0001628280-26-012438 | 10-K | XBRL Viewer

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FINANCIAL STATEMENT SCHEDULE - Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Condensed Financial Statements, Captions [Line Items]
Operating revenue	$ 800,590	$ 748,439	$ 670,363
Operating expense:
Administrative and general	125,998	105,830	98,656
Property taxes and other non-income taxes	37,686	35,928	34,475
Total operating expense	623,063	577,936	520,928
Operating income	177,527	170,503	149,435
Other (expense) income:
Interest on long-term debt and other interest expense	(72,575)	(71,390)	(66,144)
Other, net	3,545	55	8,882
Income tax benefit	12,355	8,970	5,956
Net income	102,578	93,967	84,987
Other comprehensive income, net	(493)	169	314
Comprehensive income	102,085	94,136	85,301
H2O America
Condensed Financial Statements, Captions [Line Items]
Operating revenue	0	0	0
Operating expense:
Administrative and general	4,664	5,568	2,239
Property taxes and other non-income taxes	118	388	80
Total operating expense	4,782	5,956	2,319
Operating income	(4,782)	(5,956)	(2,319)
Other (expense) income:
Interest on long-term debt and other interest expense	(17,862)	(18,022)	(17,692)
Interest income on intercompany notes receivable	6,292	6,756	3,862
Other, net	(4,613)	(3,456)	1,034
Loss before income taxes and equity earnings from subsidiaries	(20,965)	(20,678)	(15,115)
Income tax benefit	(6,015)	(5,727)	(4,294)
Equity earnings from subsidiaries, net of taxes	117,528	108,918	95,808
Net income	$ 102,578	$ 93,967	$ 84,987

Segment Reporting - Narrative (Details)	12 Months Ended
Segment Reporting - Narrative (Details)	Dec. 31, 2025 segment
Segment Reporting [Abstract]
Number of reportable segments	1

Summary of Significant Accounting Policies - Asset Retirement Obligation (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Accounting Policies [Abstract]
Estimated future retirement costs	$ 4,220	$ 4,303
Discount rate	6.00%	6.00%
Retirement obligation, present value	$ 930	$ 887

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Stockholders' Equity [Abstract]
Unrealized gain (loss) on investment, tax expense (benefit)	$ 0	$ (163)	$ 166
Adjustment to pension benefit plans, tax benefit	$ 0	$ 0	$ 80
Common stock, dividends per share, paid (usd per share)	$ 1.68	$ 1.60	$ 1.52

Commitments (Details) $ / billionGallon in Thousands, $ in Thousands						1 Months Ended	12 Months Ended
	Jun. 12, 2024	May 19, 2023 gal	Nov. 07, 2020 gal	Nov. 06, 2020	May 19, 2003	Oct. 31, 2024 USD ($) serviceConnection	Dec. 31, 2025 USD ($) acre_foot employee $ / billionGallon $ / hundredCubicFeet gal	Dec. 31, 2024 USD ($) gal	Dec. 31, 2023 USD ($) gal
Long-term Purchase Commitment [Line Items]
Purchased water \| $							$ 126,343	$ 158,568	$ 135,982
Number of service connections \| serviceConnection						4,700
Service agreement, term of contract						12 years
Service agreement, renewal term						8 years
Service agreement, upfront concession fee \| $						$ 22,100
Service agreement, annual rent expense \| $						$ 1,800
Union Member
Long-term Purchase Commitment [Line Items]
Collective bargaining agreement percent of wage increase for 2026							3.00%
Collective bargaining agreement percent of wage increase for 2027							3.00%
Collective bargaining agreement percent of wage increase for 2028							4.00%
H2O America
Long-term Purchase Commitment [Line Items]
Number of employees \| employee							396
H2O America \| Union Member
Long-term Purchase Commitment [Line Items]
Number of employees \| employee							242
RWA \| Capacity Agreement
Long-term Purchase Commitment [Line Items]
Current contract water rate \| $ / billionGallon							3,300
RWA \| Maximum \| Capacity Agreement
Long-term Purchase Commitment [Line Items]
Agreement to purchase water (in gallons of water) \| gal							1,000,000
MDC \| Capacity Agreement
Long-term Purchase Commitment [Line Items]
Current contract water rate \| $ / hundredCubicFeet							3.91
Agreement to purchase water (in gallons of water) \| gal		280,000,000
Purchase commitment period					50 years
Kennebec Water District
Long-term Purchase Commitment [Line Items]
Agreement to purchase water (in gallons of water) \| gal			50,000,000.00
Contract agreement, term			5 years	20 years
Contract agreement, renewal term			20 years
Long-term purchase commitment, wholesale discount (in USD per hundred cubic feet) \| $ / hundredCubicFeet							0.20
Tariff rate (in USD per hundred cubic feet) \| $ / hundredCubicFeet							1.51
International Union of Operating Engineers \| H2O America
Long-term Purchase Commitment [Line Items]
Bargaining agreements, term							3 years
Santa Clara Valley Water District
Long-term Purchase Commitment [Line Items]
Master contract, negotiated term for delivery schedules							3 years
Water purchased (in gallons) \| gal							15,900,000,000	17,000,000,000.0	18,300,000,000
Purchased water \| $							$ 120,322	$ 117,698	$ 111,173
Reduction in delivery schedule, percent	23.00%
Minimum percent of delivery schedule to be purchased							90.00%
Minimum volume of water to be purchased (in gallons) \| gal							18,900,000,000
Cost of water to be purchased \| $							$ 148,795
Current contract water rate \| $ / billionGallon							7,872
Guadalupe-Blanco River Authority \| SJWTX, Inc.
Long-term Purchase Commitment [Line Items]
Long-term purchase commitment, minimum area required (in acre-feet of water) \| acre_foot							7,602
Notice period required for contract adjustment							60 days
Lower Colorado River Authority \| SJWTX, Inc.
Long-term Purchase Commitment [Line Items]
Long-term purchase commitment, minimum area required (in acre-feet of water) \| acre_foot							350

Benefit Plans - Schedule of Actuarial Calculation Assumptions (Details)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Minimum \| Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate	5.55%	4.99%	4.95%
Net periodic benefit cost, expected return on plan assets	6.50%	6.25%	6.00%
Net periodic benefit cost, rate of compensation increase	4.50%	4.50%	4.50%
Benefit obligations, discount rate	5.35%	5.55%
Benefit obligations, rate of compensation increase	4.50%	4.50%
Minimum \| Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate	5.48%	4.95%	4.96%
Net periodic benefit cost, expected return on plan assets	4.20%	4.20%	4.20%
Benefit obligations, discount rate	5.11%	5.48%
Maximum \| Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate	5.63%	5.03%	5.24%
Net periodic benefit cost, expected return on plan assets	6.75%	6.75%	6.75%
Net periodic benefit cost, rate of compensation increase	5.00%	5.00%	5.00%
Benefit obligations, discount rate	5.54%	5.63%
Benefit obligations, rate of compensation increase	5.00%	5.00%
Maximum \| Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, discount rate	5.58%	5.01%	5.21%
Net periodic benefit cost, expected return on plan assets	6.50%	6.25%	6.00%
Benefit obligations, discount rate	5.43%	5.58%

Capitalization	12 Months Ended
Capitalization	Dec. 31, 2025
Equity [Abstract]
Capitalization	Capitalization H2O America is authorized to issue 70,000,000 shares of common stock of $0.001 par value per share. At December 31, 2025 and 2024, 36,118,242 and 33,629,169, respectively, shares of common stock were issued and outstanding. As of December 31, 2025 and 2024, 1,000,000 shares of preferred stock of $0.001 par value per share were authorized for H2O America. At December 31, 2025 and 2024, no shares of preferred stock were issued or outstanding. On October 29, 2024, H2O America entered into an equity distribution agreement (the, “New Equity Distribution Agreement”) with BofA Securities, Inc., J.P. Morgan Securities LLC, RBC Capital Markets, LLC and Wells Fargo Securities, LLC, pursuant to which the company may offer and sell shares of its common stock, $0.001 par value per share, from time to time in “at-the-market” offerings, having an aggregate gross sales price of up to $200,000. Since the inception of the New Equity Distribution Agreement, H2O America has issued and sold 2,763,359 shares of common stock at a weighted average price of $52.39 for a total net proceeds of $142,975 and has $55,239 of aggregate gross sales price of shares remaining to issue under the New Equity Distribution Agreement as of December 31, 2025. For the year ended December 31, 2025, H2O America issued and sold a total of 2,387,846 shares of common stock with a weighted average price of $51.90 per share and received $122,806 in net proceeds under the aforementioned equity distribution agreements.

- Definition

The entire disclosure for equity.

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+ Details

Income Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Deferred tax assets:
Advances and contributions	$ 28,183	$ 26,744
Unamortized investment tax credit	1,141	1,061
Pensions, postretirement benefits and stock-based compensation	11,749	12,529
Debt premium, net	2,734	3,446
California franchise tax	257	503
Deferred revenue	0	0
Tax related regulatory liability	22,572	23,112
Other	9,560	6,337
Total deferred tax assets	76,196	73,732
Deferred tax liabilities:
Utility plant	304,002	277,085
Pension and postretirement	9,272	9,068
Deferred gain and other-property	608	608
Regulatory asset - business combinations debt premium, net	2,734	3,446
Intangibles	2,193	2,443
Deferred revenue	2,330	1,418
Tax related regulatory asset	57,503	50,728
Other	5,447	4,979
Total deferred tax liabilities	384,089	349,775
Net deferred tax liabilities	$ 307,893	$ 276,043

Segment Reporting

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Segment Reporting

H2O America’s single reportable segment provides water utility and utility-related services to its customers through H2O America’s subsidiaries, SJWC, CWC, TWC, MWC, and Acequia, which are aggregated and referred to as “Water Utility Services.” Water Utility Services’ activities are water utility operations with both regulated and non-tariffed businesses. Other business activities that do not comprise separately reportable segments primarily include SJWC’s City of Cupertino service concession arrangement operations, property management and investment activity conducted by H2O America Land Company and Chester Realty, Inc., contract water and sewer operations and other water-related services provided by NEWUS are referred to as “Other Services.”

H2O America’s operating segments have been determined based on information used by the chief operating decision maker. H2O America’s chief operating decision makers (“CODM”) include the Chair and Chief Executive Officer; the Chief Financial Officer and Treasurer; the President and Chief Operating Officer; the President of Shared Services and Senior Vice President and Chief Administrative Officer; and the Vice President and General Counsel. However, ultimate decision-making authority rests with the Chair and Chief Executive Officer. The CODM reviews financial information presented on a consolidated basis that is accompanied by certain disaggregated information about operating revenue, expenses, net income, and total assets. The CODM uses the net income to assess the financial performance of the segments and allocate resources (including employees, financial, or capital resources) in the budgeting and forecasting process.

Previously, H2O America presented a separate reportable segment for Real Estate Services and also presented a disaggregation of regulated and non-tariffed activities within the Water Utility Services reportable segment. Considering the sale of the Tennessee properties, as discussed in Note 2, which were part of the Real Estate Services segment, management has updated its segment presentation and has recast the prior periods presented to conform with the current period presentation. Under the current presentation, the activities of Water Utility Services previously presented as “non-tariffed” are generally presented as “Other Services” along with the real estate activity. Certain allocated assets, such as goodwill, revenue and expenses have been included in the reportable segment amounts. Certain corporate costs and expenses are not allocated to Water Utility Services or Other Services and are shown separately to reconcile to the applicable consolidated amounts.


	For the year ended December 31, 2025
	Reportable Segment
	Water Utility Services		Other Services (1)	Unallocated Corporate (2)	Consolidated
Operating revenue	$	787,099	13,491	—	800,590

Less:
Production expenses	305,460		5,701	—	311,161
Administrative and general	119,665		1,306	5,027	125,998
Maintenance	30,124		2,771	—	32,895
Property taxes and other non-income taxes	37,521		47	118	37,686
Depreciation and amortization	114,286		121	916	115,323
Interest on long-term debt and other interest expense	51,463		—	21,112	72,575

Provision (benefit) for income taxes	19,928		1,371	(8,944)	12,355
Other (3)	(6,531)		(587)	(2,863)	(9,981)
Net income (loss)	$	115,183	2,761	(15,366)	102,578

Capital expenditures	$	519,753	—	—	519,753


	For the year ended December 31, 2024
	Reportable Segment
	Water Utility Services		Other Services (1)	Unallocated Corporate (2)	Consolidated
Operating revenue	$	732,580	15,859	—	748,439

Less:
Production expenses	286,763		5,259	—	292,022
Administrative and general	97,420		2,632	5,778	105,830
Maintenance	29,249		2,052	—	31,301
Property taxes and other non-income taxes	35,223		317	388	35,928
Depreciation and amortization	111,709		253	893	112,855
Interest on long-term debt and other interest expense	47,485		521	23,384	71,390

Provision (benefit) for income taxes	17,134		1,569	(9,733)	8,970
Other (3)	(920)		191	(3,095)	(3,824)
Net income (loss)	$	108,517	3,065	(17,615)	93,967

Capital expenditures	$	377,208	29	—	377,237


	For the year ended December 31, 2023
	Reportable Segment
	Water Utility Services		Other Services (1)	Unallocated Corporate (2)	Consolidated
Operating revenue	$	652,045	18,318	—	670,363

Less:
Production expenses	251,898		4,302	—	256,200
Administrative and general	93,255		2,777	2,624	98,656
Maintenance	23,972		1,757	—	25,729
Property taxes and other non-income taxes	33,469		926	80	34,475
Depreciation and amortization	104,329		646	893	105,868
Interest on long-term debt and other interest expense	42,743		329	23,072	66,144

Provision (benefit) for income taxes	11,293		2,213	(7,550)	5,956
Other (3)	(4,279)		(121)	(3,252)	(7,652)
Net income (loss)	$	95,365	5,489	(15,867)	84,987

Capital expenditures	$	288,627	24,244	—	312,871

___________________________________

(1) The “Other Services” category includes the accounts of H2O America Land Co, Chester Reality, Inc., SJWC’s Cupertino service concession arrangement operations, TWOS, TWR, and NEWUS, on a stand-alone basis.

(2) The “Unallocated Corporate” category includes the accounts of H2O America, H2O America NE LLC, H2O America TX Holdings, Inc., CTWS, NWU on a stand-alone basis.

(3) Primarily comprised of pension non-service credit (cost) and items of miscellaneous non-operating income (expense).

H2O America’s assets for the Water Utility Services reportable segment and all other are as follows as of December 31:


	2025		2024
Water Utility Services (reportable segment)	$	5,054,235	4,567,182
Other Services	26,707		25,053
Unallocated Corporate	68,624		66,074
Total assets	$	5,149,566	4,658,309

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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+ Details

Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 51,683	$ 51,604
Amortization of intangible assets	1,095	1,429	$ 1,310
Future Amortization of Intangible Assets
2026	1,095
2027	1,095
2028	1,095
2029	1,095
2030	1,095
Thereafter	1,095
Purchase premium customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets	13,400	13,400
Other intangibles
Finite-Lived Intangible Assets [Line Items]
Intangible assets	9,897	9,818
Service Agreements
Finite-Lived Intangible Assets [Line Items]
Intangible assets	4,371
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets	1,400
Contractual Rights
Finite-Lived Intangible Assets [Line Items]
Intangible assets	1,040
Indefinite-lived water rights
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived water rights	$ 28,386	$ 28,386

FINANCIAL STATEMENT SCHEDULE (Tables)

12 Months Ended

Dec. 31, 2025

Condensed Financial Information Disclosure [Abstract]

Schedule of Maturities of Long-term Debt

The following is a table of the consolidated company’s schedule of principal payments:


Year
2026	$	23,950
2027	3,207
2028	44,699
2029	325,624
2030	53,201
Thereafter	1,450,520

The following is a table of the H2O America’s schedule of principal payments on long-term debt:


Year
2026	$	—
2027	—
2028	—
2029	310,000
2030	50,000
Thereafter	200,000

Summary of Significant Accounting Policies - Financial Instruments and Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Accounting Policies [Abstract]
Bank owned life insurance	$ 9,870	$ 8,944
Value of life insurance contracts	$ 4,852	$ 4,294

Regulatory Matters - Schedule of Regulatory Assets, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Regulatory assets:
Total regulatory assets	$ 254,862	$ 242,227
Less: current regulatory asset	8,315	18,172
Total regulatory assets, less current portion	246,547	224,055
Regulatory liabilities:
Total regulatory liabilities	546,797	484,841
Less: current regulatory liabilities	0	1,122
Total regulatory liabilities, less current portion	$ 546,797	483,719
Minimum
Regulatory liabilities:
Estimated service lives of assets	5 years
Maximum
Regulatory liabilities:
Estimated service lives of assets	100 years
Cost of removal
Regulatory liabilities:
Total regulatory liabilities	$ 394,391	364,398
Future income tax benefits due to customers
Regulatory liabilities:
Total regulatory liabilities	82,285	84,128
Unrecognized pensions and other postretirement benefits
Regulatory liabilities:
Total regulatory liabilities	32,996	27,872
PFAS Legal Settlement Proceeds
Regulatory liabilities:
Total regulatory liabilities	24,682	0
Employee benefit costs
Regulatory liabilities:
Total regulatory liabilities	8,771	1,137
Revenue adjustment mechanisms
Regulatory liabilities:
Total regulatory liabilities	0	1,122
Water supply costs
Regulatory liabilities:
Total regulatory liabilities	0	3,386
Other
Regulatory liabilities:
Total regulatory liabilities	3,672	2,798
Future income tax benefits due to customers
Regulatory assets:
Total regulatory assets	204,384	180,103
MWRAM
Regulatory assets:
Total regulatory assets	8,553	9,985
Business combinations debt premium
Regulatory assets:
Total regulatory assets	9,772	12,313
Employee benefit costs
Regulatory assets:
Total regulatory assets	5,823	6,370
Catastrophic event memorandum accounts (“CEMA”)
Regulatory assets:
Total regulatory assets	127	986
Revenue adjustment mechanisms
Regulatory assets:
Total regulatory assets	7,931	5,024
Customer Assistance Program (“CAP”) balancing account
Regulatory assets:
Total regulatory assets	3,696	6,599
Water supply costs
Regulatory assets:
Total regulatory assets	847	0
Unrecognized pensions and other postretirement benefits
Regulatory assets:
Total regulatory assets	0	3,177
2022 general rate case interim memorandum account
Regulatory assets:
Total regulatory assets	0	3,392
Other
Regulatory assets:
Total regulatory assets	$ 13,729	$ 14,278

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Depreciable Utility Plant and Equipment

The major components of depreciable plant and equipment as of December 31, 2025 and 2024 are as follows:


	2025		2024
Source of supply	$	243,335	228,621
Pumping plant	331,134		301,280
Water treatment plant	396,061		367,836
Transmission and distribution plant	3,323,482		3,015,978
General plant	394,632		335,599
Total depreciable plant and equipment	$	4,688,644	4,249,314

Depreciation is computed using the straight-line method over the estimated remaining service lives of groups of assets. The estimated service lives of depreciable plant and equipment are as follows:


			Useful Lives
Source of supply			20 to 100 years
Pumping plant			5 to 70 years
Water treatment plant			5 to 62 years
Transmission and distribution plant			10 to 100 years
General plant			5 to 68 years

For the years 2025, 2024 and 2023, depreciation expense as a percentage of the beginning of the year balance of depreciable plant was 2.75%, 2.9% and 2.9%, respectively. Depreciation expense for utility plant for the years ended December 31, 2025, 2024 and 2023 was $114,265, $111,575 and $104,325, respectively. The cost of utility plant retired (less salvage) is charged to accumulated depreciation and no gain or loss is recognized. To the extent H2O America recovers retirement costs through rates during the life of the associated asset and before the costs are incurred, these amounts result in a regulatory liability being reported based on the amounts previously recovered through customer rates until the costs to retire those assets are incurred.

Allowance For Funds Used During Construction (“AFUDC”)

AFUDC represents the capitalized costs of borrowed funds or a return on equity funds used to finance utility plant under construction and is capitalized as part of construction work in progress. AFUDC is recorded to the extent approved by the respective states’ utility regulators and is recovered through water rates as the utility plant depreciates. The amount of AFUDC debt capitalized in 2025, 2024 and 2023 was $7,335, $3,524 and $2,900, respectively. Interest on long-term debt is presented net of AFUDC debt capitalized on the Consolidated Statements of Comprehensive Income. The amount of AFUDC equity capitalized in 2025, 2024 and 2023 was $6,237, $2,362 and $2,114, respectively, reflected in “Other, net” on the Consolidated Statements of Comprehensive Income.

Intangible Assets

Finite-lived intangible assets are recorded at cost and are amortized using the straight-line method over the estimated useful life of the asset, ranging from 3 to 70 years. Indefinite-lived intangibles assets are not amortized, but instead are tested for impairment annually, or more frequently if events or changes in circumstances indicate that it is more likely than not that the asset is impaired. (see Note 8, “Intangible Assets”).

Nonutility Properties and Real Estate Investments

Nonutility properties and real estate investments are recorded at cost and consist primarily of land and buildings. Net gains and losses from the sale of nonutility properties and real estate investments are recorded as a component of other (expense) income and operating expense, respectively, in the Consolidated Statements of Comprehensive Income. Nonutility property is property that is neither used nor useful in providing water utility services to customers and is excluded from rate base for rate-setting purposes. SJWC recognizes gain or loss on the disposition of nonutility property in accordance with California Public Utilities Commission (“CPUC”) Code Section 790, whereby the net proceeds are reinvested back into property that is useful in providing water utility services to customers. CTWS and TWC do not have regulatory restrictions on the use of proceeds from the sale of nonutility property. There is no depreciation associated with Water Utility Services nonutility property as it is all undeveloped land.

The major components of nonutility properties and real estate investments are as follows as of December 31:


	2025		2024
Land	$	914	915
Wholesale water supply assets	—		—
Buildings and improvements	769		399

Subtotal	1,683		1,314
Less: accumulated depreciation and amortization	103		98
Total	$	1,580	1,216

Depreciation on buildings and improvements for real estate investments is computed using the straight-line method over the estimated useful lives of the assets, ranging from 7 to 39 years.

Business Combinations and Asset Acquisitions

H2O America applies the provisions of Financial Accounting Standards Board (“FASB”) ASC Topic 805—“Business Combinations” for the accounting related to business and asset acquisitions. First, H2O America applies the guidance in Topic 805 to determine whether a transaction represents a business combination or an acquisition of assets. If the transaction is a business combination, Topic 805 requires H2O America to recognize separately from goodwill the assets acquired and the liabilities assumed at the acquisition date fair values. Goodwill as of the acquisition date is measured as the excess of consideration transferred over the net of the acquisition date fair values of the assets acquired and the liabilities assumed. If the transaction is an acquisition of assets, the cost of the transaction, including transaction costs, is allocated to the individual assets acquired and liabilities assumed on a relative fair value basis without recognition of goodwill. While H2O America uses best available estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date, such estimates are inherently uncertain and subject to refinement. For business combinations, Topic 805 provides for a measurement period from the acquisition date of up to one year, during which we may record adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill. Upon the conclusion of the measurement period, any subsequent adjustments are recorded to the Consolidated Statements of Comprehensive Income. Accounting for business combinations and asset acquisitions requires H2O America to make significant estimates and assumptions, especially at the acquisition date, including estimates for intangible assets, contractual obligations assumed and pre-acquisition contingencies. Although H2O America believes that the assumptions and estimates we make are reasonable and appropriate, they are based in part on historical experience and information obtained from the acquired company’s management and are inherently uncertain. Events and circumstances may occur that may affect the accuracy or validity of such assumptions, estimates or actual results. Examples of critical estimates in valuing certain of the intangible assets we have acquired include, but are not limited to: future expected cash flows from services; historical and expected customer attrition rates and anticipated growth in revenue from acquired customers; the expected use of the acquired assets; and discount rates. See Note 14, “Acquisitions” for further information on business combinations and asset acquisitions.

Impairment of Long-Lived Assets and Goodwill

In accordance with the requirements of FASB ASC Topic 360—“Property, Plant and Equipment,” the long-lived assets of H2O America, including property, plant and equipment and finite-lived intangible assets, are reviewed for impairment when changes in circumstances or events indicate that the carrying amount of the assets may not be recoverable. In assessing qualitative factors, H2O America considers the impact of these key factors: change in industry and competitive environment, financial performance, and other relevant company-specific events. When such changes in circumstances or events occur, the company assesses recoverability by determining whether the carrying value of such assets will be recovered through the undiscounted expected future cash flows. To the extent an impairment exists, the asset is written down to its estimated fair value with a corresponding charge to operations in the period in which the impairment is identified. No impairments occurred during 2025 and 2024.

Goodwill is not amortized but is tested for impairment annually on October 1st or more frequently if an event occurs or circumstances change that would, more likely than not, reduce the fair value of a reporting unit below its carrying amount. Indefinite-lived intangible assets, other than goodwill, are not amortized but are tested for impairment annually on October 1st or more frequently if an event occurs or circumstances change that would, more likely than not, reduce the fair value of indefinite-lived intangible assets below their carrying amount. In performing impairment tests of goodwill and indefinite-lived intangible assets, H2O America first performs a qualitative assessment to determine whether it is necessary to perform the quantitative impairment test. In assessing the qualitative factors, H2O America considers the impact of these key factors: change in industry and competitive environment, financial performance, macroeconomic conditions, and other relevant Company-specific events. If H2O America determines that as a result of the qualitative assessment it is more likely than not (> 50% likelihood) that the fair value is less than carrying amount, then a quantitative test is performed. As of October 1, 2025, H2O America performed qualitative assessments of both goodwill and indefinite-lived intangible assets and found no indicators of impairment and therefore did not perform quantitative impairment tests. No impairments of goodwill or indefinite-lived intangible assets occurred during 2025, 2024 or 2023.

Cash and Cash Equivalents

Cash and cash equivalents primarily consisted of cash on deposit with banks and short-term, highly liquid investments with original maturities of three months or less.

Accounts Receivable

Accounts receivable are recorded at the invoiced amounts. The allowance for uncollectible accounts is H2O America’s best estimate of credit losses in its existing accounts receivable and is determined based on current expected losses. The estimate is

based on historical loss information adjusted for current conditions. Accounts balances are written off against the allowance when it is probable the receivable will not be recovered or is over a certain number of days outstanding. During the second quarter of 2024, H2O America recorded a reduction to its allowance for credit losses of $7,822, of which $3,960 resulted in a reduction to regulatory assets and $3,862 was recorded through administrative and general expense.

Financial Instruments and Investments

The following instruments are not measured at fair value on the company’s Consolidated Balance Sheets but require disclosure of fair values: cash and cash equivalents, accounts receivable, accounts payable, and lines of credit. The estimated fair value of such instruments approximates their carrying value as reported on the Consolidated Balance Sheets. The fair value of such financial instruments are determined using the income approach based on the present value of estimated future cash flows. The fair value of these instruments would be categorized as Level 2 in the fair value hierarchy, with the exception of cash and cash equivalents, which would be categorized as Level 1. The fair value of long-term debt is discussed in Note 6, “Long-Term Debt” and pension plan assets in Note 11, “Benefit Plans.”

H2O America has investments in company owned life insurance which are valued at cash surrender value of the policies as reported by the insurer. The value of these contracts is based principally on a referenced pool of investment funds that actively redeem shares, are observable and measurable, and are presented in “Investments” on H2O America’s Consolidated Balance Sheets. As of December 31, 2025 and 2024, the value of the company owned life insurance was $9,870 and $8,944, respectively, of which $4,852 and $4,294, respectively, was related to assets to fund CTWS’ supplemental retirement plan agreements. See discussion on pension plans in Note 11, “Benefit Plans.”

Income Taxes

Income taxes are accounted for using the asset and liability method. Deferred tax assets and liabilities are recognized for the effect of temporary differences between financial and tax reporting. Deferred tax assets and liabilities are measured using current tax rates in effect. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that includes the enactment date.

To the extent permitted by the regulators, investment tax credits resulting from public utility plant additions are deferred and amortized over the estimated useful lives of the related property. In addition, investment tax credits resulting from other asset additions are recognized in the year the property is put in service.

Advances for Construction and Contributions in Aid of Construction

In California, advances for construction received after 1981 are primarily refunded ratably over 40 years. In Connecticut and Maine, advances for construction are refunded as services are connected to the main over periods not exceeding 15 years and in Texas advances for construction are primarily non-refundable. Estimated refunds for the next five years and thereafter are shown below:


	Estimated Refunds
2026	$	2,569
2027	2,535
2028	2,615
2029	2,592
2030	2,549
Thereafter	45,627

As of December 31, 2025, advances for construction totaled $201,413 including $108,311 in non-refundable advances and $34,615 in advances that will be refunded based on service connections made, though the timing of these refunds cannot be estimated. As of December 31, 2024, advances for construction totaled $155,397 including $64,920 in non-refundable advances and $31,983 in advances that will be refunded based on service connections made, though the timing of these refunds cannot be estimated. As of December 31, 2025 and 2024, the fair value of the advances for construction refunded ratably over 40 years is $51,356 and $43,718, respectively.

Contributions in aid of construction represent funds or property received from developers that are not refundable under applicable regulations. Depreciation applicable to utility plant constructed with these contributions is charged to contributions in aid of construction.

Asset Retirement Obligation

H2O America’s asset retirement obligation is recorded as a liability included in other non-current liabilities. It reflects principally the retirement costs of wells and other anticipated clean-up costs, which by law, must be remediated upon retirement.

As of December 31, 2025 and 2024, the asset retirement obligation is as follows:


	2025			2024
Estimated future retirement costs	$	4,220		4,303
Discount rate	6		%	6	%


Retirement obligation, present value	$	930		887

Revenue

H2O America recognizes revenue under ASC Topic 606—“Revenue from Contracts with Customers” for metered revenue of Water Utility Services, which includes billings to customers based on meter readings plus an estimate of water used between the customers’ last meter reading and the end of the accounting period. H2O America satisfies its performance obligation upon delivery of water to the customer at which time the customer consumes the benefits provided by the company. The customer is generally billed on a quarterly, monthly, or bi-monthly basis after water delivery has occurred. The customer is charged both a service charge which is based upon meter size and covers a portion of the fixed costs of furnishing water to the customer and a consumption charge based on actual water usage. Unbilled revenue from the last meter reading date to the end of the accounting period is estimated based on the most recent usage patterns, production records and the effective tariff rates. As the company has the right to bill for services that it has provided, H2O America estimates the dollar value of deliveries during the unbilled period and recognizes the associated revenue. Actual results could differ from those estimates, which may result in an adjustment to revenue when billed in a subsequent period.

H2O America also recognizes revenue under ASC Topic 980-605-25—“Alternative Revenue Programs.” Under programs established by the CPUC and Public Utilities Regulatory Authority of Connecticut (“PURA”), allowing for automatic adjustment of future rates, the company recognizes revenue when it is objectively determinable, probable of recovery and expected to be collected within 24 months of the year-end in which the revenue is recognized. A reserve, based on an estimate of actual usage over the recovery period, is recorded for any amounts H2O America estimates will not be collected within the 24-month period. H2O America’s alternative revenue programs include SJWC’s Water Conservation Memorandum Account (“WCMA”) and CWC’s Water Rate Adjustment mechanism (“WRA”). See further discussion on WCMA and WRA in Note 3, “Regulatory Matters.”

H2O America’s revenues also reflect the impact of other balancing and memorandum accounts and other regulatory mechanisms that are accounted for under FASB ASC Topic 980—“Regulated Operations.” Balancing and memorandum accounts are recognized when it is probable that future recovery of previously incurred costs or future refunds that are to be credited to customers will occur through the ratemaking process. See further discussion in Note 3, “Regulatory Matters.”

H2O America also recognizes revenue from rental income, which represents lease rental income. Tenants pay monthly in accordance with lease agreements and H2O America recognizes the income ratably over the lease term as this is the most representative of the pattern in which the benefit is expected to be derived from H2O Americas underlying asset.

Detail of H2O America’s revenue components are as follows for the years ended December 31:


	2025		2024	2023
Revenue from contracts with customers	$	805,594	736,326	678,168
Alternative revenue programs, net	6,672		6,181	3,634
Other balancing and memorandum accounts and regulatory mechanisms, net	(11,919)		(153)	(17,123)
Rental income	243		6,085	5,684
	$	800,590	748,439	670,363

Revenue also includes a surcharge collected from regulated customers that is paid to the CPUC. This surcharge is recorded both in operating revenue and administrative and general expenses. For the years ended December 31, 2025, 2024 and 2023, the surcharge was $3,927, $3,668 and $4,085, respectively.

Share-Based Compensation

H2O America calculates the fair value of service-based and performance-based restricted stock awards based on the grant date fair value of the company’s stock price reduced by the present value of the dividends expected to be declared on outstanding shares.

H2O America utilizes the Monte Carlo valuation model, which requires the use of subjective assumptions, to compute the fair value of market-vesting restricted stock units.

The compensation cost for service-based restricted stock awards is charged to income on a straight-line basis over the requisite service period, which is the vesting period. For performance-based stock awards, compensation expense is charged to income on a straight-line basis over the requisite service period based on expected attainment of performance targets. Changes in the estimates of the expected attainment of performance targets will result in a change in the number of shares that are expected to vest which may cause a cumulative catch up for the amount of share-based compensation expense during each reporting period in which such estimates are altered. Forfeitures are accounted for as they occur.

Earnings per Share

Basic earnings per share is calculated using income available to common stockholders, divided by the weighted average number of shares outstanding during the period. Diluted earnings per share is calculated using income available to common stockholders divided by the weighted average number of shares of common stock including both shares outstanding and shares potentially issuable in connection with restricted common stock awards under H2O America’s long-term incentive plans, shares potentially issuable under the performance stock plans assumed through the business combination with CTWS, and shares potentially issuable under H2O America’s employee stock purchase plans. Restricted common stock units of 40,452, 8,075 and 14,193 as of December 31, 2025, 2024 and 2023, respectively, were excluded from the diluted earnings per share calculation as their effect would have been antidilutive.

Related-Party Transaction

The Force for Good Foundation, established in 2024, is a non-consolidated not-for-profit corporation funded by H2O America that has made and continues to make contributions to selected charitable organizations. H2O America made contributions of $4,400 and $3,000 in 2025 and 2024 respectively, which are included as an expense in the “Other, net” line of the Consolidated Statements of Comprehensive Income.

New Accounting Standards

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2023-09 “Improvements to Income Tax Disclosures”

The ASU amends certain income tax disclosure requirements, including adding requirements to present the reconciliation of income tax expense computed at the statutory rate to actual income tax expense using both percentages and amounts and providing a disaggregation of income taxes paid. Further, certain disclosures are eliminated, including the current requirement to disclose information on changes in unrecognized tax benefits in the next 12 months.

The ASU was adopted with the annual financial statements for the year ended December 31, 2025.

Prospective, with retrospective application also permitted.

The standard only resulted in updates to disclosure and did not have a material impact on the Company’s financial position and results of operations.

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2024-03 “Disaggregation of Income Statement Expenses”

The ASU requires disclosure, in the notes to the financial statements, of specified information about certain costs and expenses. The ASU requires disclosure of purchases of inventory, employee compensation, depreciation, and intangible asset amortization in interim and annual reporting periods. Further, other amounts already required to be disclosed in accordance with current U.S. GAAP would be included in the same disclosure as the other disaggregation requirements. Additionally, the ASU requires qualitative descriptions of amounts remaining in relevant expense captions that are not separately disaggregated quantitatively as well as disclosure of selling expenses in annual periods and an entity’s definition of selling expenses.

The ASU is effective for H2O America for its annual financial statements for the year ending December 31, 2027 and for interim reporting periods for the year ending December 31, 2028. Early adoption is permitted.

Prospective, with retrospective application also permitted.

The standard is expected to only result in updates to disclosure and is not expected to have a material impact on the Company’s financial position and results of operations.

ASU 2025-06 “Intangibles-Goodwill and Other-Internal-Use Software (subtopic 350-40)”

The ASU updates the accounting for internal-use software by removing project stage references and introduces a new capitalization threshold based on management authorization and project completion probability. The guidance requires evaluation of significant development uncertainty, including novel functionality and unresolved performance requirements. ASU 2025-06 clarifies that capitalized internal-use software costs are subject to the property, plant and equipment disclosure requirements under ASC 360-10.

The ASU is effective for H2O America for its annual financial statements for the year ending December 31, 2028 and for interim reporting periods for the year ending December 31, 2028.

Prospective, retrospective or on a modified transition approach with early adoption permitted.

H2O America is currently evaluating the impact of ASU 2025-06 on its financial statements and will adopt ASU 2025-06 in fiscal year ended December 31, 2028.

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2025-10 “Government Grants (Topic 832)”

The ASU establishes accounting for government grants received by business entities and includes guidance for (1) a grant related to an asset and (2) a grant related to income. The ASU requires that a government grant should not be recognized until it is probable that a business entity will comply with the conditions attached to the grant and the grant will be received. Additionally, the ASU requires that a grant related to an asset be recognized on the balance sheet as the business entity incurs the related costs for which the grant is intended to compensate either as deferred income or an adjustment to the cost basis of the related asset. A grant related to income or a grant recognized as deferred income should be recognized in earnings on a systematic and rational basis over the periods in which the related costs are incurred that the grant is intended to compensate.

The ASU is effective for H2O America for annual reporting periods beginning after December 15, 2028 and interim reporting periods within those annual reporting periods. Early adoption is permitted.

Retrospective adoption with modified prospective and modified retrospective application also permitted.

H2O America is currently evaluating the impact of ASU 2025-10 on its financial statements and will adopt ASU 2025-10 in fiscal year ended December 31, 2029.

ASU 2025-11 “Interim Reporting (Topic 270)”

The ASU provides clarity about the current requirements, rather than evaluate whether to expand or reduce interim disclosure requirements. The ASU includes a disclosure principle that requires entities to disclose events since the end of the last annual reporting period that have a material impact on the entity. The intent of the disclosure principle, which is modeled after a previous SEC disclosure requirement, is to help entities determine whether disclosures not specified in Topic 270 should be provided in interim reporting periods.

The ASU is effective for H2O America for interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted.

Prospective, with retrospective application also permitted.

H2O America is currently evaluating the disclosure impact of ASU 2025-11; however, the standard is not expected to impact the consolidated financial position, results of operations or cash flows.

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense

The components of income tax expense were:


	2025		2024	2023
Current:
Federal	$	5,276	(1,828)	10,185
State	1,896		443	4,281
Deferred:
Federal	5,360		11,063	(8,871)
State	(177)		(708)	361
	$	12,355	8,970	5,956

Schedule of Effective Income Tax Rate Reconciliation

The following table reconciles income tax expense to the amount computed by applying the federal statutory rate to income before income taxes of $114,933, $102,937 and $90,943 in 2025, 2024 and 2023, respectively:


	2025 (a)				2024	2023
Income tax at federal statutory rate	$	24,136	21.0	%	21,617	19,098
Increase (decrease) in taxes attributable to:
State and local income taxes, net of federal income tax effect (b)	1,326		1.2	%	6,488	6,001

Tax credits	(208)		(0.2)	%	—	—
Nontaxable or nondeductible items	543		0.5	%	—	—
Changes in unrecognized tax benefits	331		0.3	%	(1,053)	(4,330)
Property flow-through	—		—	%	(14,793)	(9,045)


Pension flow-through	—		—	%	(530)	(597)
Stock-based compensation	—		—	%	192	(491)
Other adjustments:
Impact of rate regulation
Flow-through	(11,933)		(10.4)	%	—	—
Reversal of excess deferred taxes recognized in regulatory liability	(1,517)		(1.3)	%	(3,227)	(3,625)

Other items	(323)		(0.3)	%	276	(1,055)
	$	12,355	10.8	%	8,970	5,956

(a)ASU 2023-09 “Improvements to Income Tax Disclosures” was adopted prospectively with the annual financial statements for the year ended December 31, 2025. Accordingly, the table above was updated for the year ended December 31, 2025 to present disclosures as per the new ASU.

(b)Majority of the tax expense reported in this category relates to California. State flow-through adjustments are included in this category for the year ended December 31, 2025.

Schedule of Deferred Tax Assets and Liabilities

The components of the net deferred tax liability as of December 31 were as follows:


	2025		2024
Deferred tax assets:
Advances and contributions	$	28,183	26,744
Unamortized investment tax credit	1,141		1,061
Pensions, postretirement benefits and stock-based compensation	11,749		12,529
Debt premium, net	2,734		3,446
California franchise tax	257		503

Deferred revenue	—		—
Tax related regulatory liability	22,572		23,112
Other	9,560		6,337


Total deferred tax assets	76,196		73,732
Deferred tax liabilities:
Utility plant	304,002		277,085
Pension and postretirement	9,272		9,068
Deferred gain and other-property	608		608
Regulatory asset - business combinations debt premium, net	2,734		3,446
Intangibles	2,193		2,443
Deferred revenue	2,330		1,418
Tax related regulatory asset	57,503		50,728


Other	5,447		4,979
Total deferred tax liabilities	384,089		349,775
Net deferred tax liabilities	$	307,893	276,043

Schedule of Unrecognized Tax Benefits Roll Forward

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:


	2025		2024	2023
Balance at beginning of year	$	3,707	4,511	9,004
Increase related to tax positions taken during the current year	663		658	231
Increase related to tax positions taken during a prior year	113		380	364
Reductions related to statute expiration	(389)		(1,701)	(1,191)
Reductions related to tax positions taken in a prior year	—		(141)	(3,897)

Balance at end of year	$	4,094	3,707	4,511

Schedule of Income Taxes Paid (Net of Refunds)

Income Taxes paid (net of refunds) for the year ending December 31, 2025 were as below:


	2025
Federal	$	2,000
State	1,238
Foreign	—
Total	$	3,238

Income Taxes paid (net of refunds) exceeded 5% of total income taxes paid (net of refunds) in the following jurisdictions:


State:	2025
California	$	400
Connecticut	521
Maine	*
Tennessee	219
Texas	*
Total	$	1,140

*Jurisdiction below the threshold for the period presented

Summary of Significant Accounting Policies - Property, Plant and Equipment and Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Major components of depreciable plant and equipment [Abstract]
Source of supply	$ 243,335	$ 228,621
Pumping plant	331,134	301,280
Water treatment plant	396,061	367,836
Transmission and distribution plant	3,323,482	3,015,978
General plant	394,632	335,599
Total depreciable plant and equipment	$ 4,688,644	$ 4,249,314
Useful Lives
Depreciation expense as percentage of beginning of year balance of depreciable plant	2.75%	2.90%	2.90%
Capitalized interest costs	$ 7,335	$ 3,524	$ 2,900
Equity funds capitalized	6,237	2,362	2,114
Water Plant
Useful Lives
Depreciation	$ 114,265	$ 111,575	$ 104,325
Minimum
Useful Lives
Source of supply	20 years
Pumping plant	5 years
Water treatment plant	5 years
Transmission and distribution plant	10 years
General plant	5 years
Useful life of intangible assets	3 years
Maximum
Useful Lives
Source of supply	100 years
Pumping plant	70 years
Water treatment plant	62 years
Transmission and distribution plant	100 years
General plant	68 years
Useful life of intangible assets	70 years

FINANCIAL STATEMENT SCHEDULE - Narrative (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Condensed Financial Information Disclosure [Abstract]
Restricted net assets, subsidiaries	$ 501,724
Restricted net assets, subsidiaries, percent of consolidated assets	33.00%

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2025

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

Long-term debt as of December 31 was as follows:


Description	Rate	Maturity	2025		2024

H2O America Senior notes (a)	2.47% - 3.53%	2029 - 2039	$	560,000	560,000
SJWC:
Senior notes (a)	3.00% - 7.20%	2026 - 2055	560,000		505,000
California Pollution Control Financing Authority Revenue Bond	4.75%	2046	70,000		70,000
Total SJWC			630,000		575,000
CTWS bank term loans	4.09%, 4.15%	2027, 2037	12,212		14,389
CWC:
Connecticut Innovations Revenue Bonds, variable rate		2028 - 2029	22,050		22,050
Senior notes (a)	3.07% - 6.46%	2037 - 2055	330,000		270,000
State revolving fund loans	2.00%	2044	308		327
Bank term loans	4.04% - 4.75%	2028 - 2036	96,295		96,295
Total CWC			448,653		388,672
TWC:
Senior note (a)	6.27%	2036	15,000		15,000
Bank term loans	4.01% - 6.68%	2041 - 2055	105,000		65,000
Seller financing debt	(b)	2053	29,000		29,000
Total TWC			149,000		109,000

MWC:
State revolving fund loans	0.00% - 2.23%	2026 - 2054	16,336		12,763
Bank term loans	3.89% - 6.47%	2026 - 2055	85,000		60,000
Total MWC			101,336		72,763
Total debt			1,901,201		1,719,824
Unamortized debt premium and discount, net			(1,644)		(56)

Unamortized debt issuance costs			(9,234)		(9,216)
Current portion			(23,504)		(3,648)
Total long-term debt, less current portion			$	1,866,819	1,706,904

___________________________________

(a)Senior notes held by institutional investors are unsecured obligations of H2O America, SJWC, CWC, TWC and MWC and require interest-only payments until maturity. To minimize issuance costs, the companies’ debt has primarily been placed privately.

(b)Debt does not contain a stated interest rate but is discounted using an effective rate of 5.61%.

Schedule of Maturities of Long-term Debt

The following is a table of the consolidated company’s schedule of principal payments:


Year
2026	$	23,950
2027	3,207
2028	44,699
2029	325,624
2030	53,201
Thereafter	1,450,520

The following is a table of the H2O America’s schedule of principal payments on long-term debt:


Year
2026	$	—
2027	—
2028	—
2029	310,000
2030	50,000
Thereafter	200,000

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

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-Paragraph 1
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 3
-Subparagraph (SX 210.12-04(a))
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Reference 5: http://www.xbrl.org/2003/role/exampleRef
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-Paragraph 69B
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Reference 6: http://www.xbrl.org/2003/role/exampleRef
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-URI https://asc.fasb.org/1943274/2147481568/470-20-55-69E

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
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-Name Accounting Standards Codification
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-Paragraph 2
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-URI https://asc.fasb.org/1943274/2147482925/835-30-45-2

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI https://asc.fasb.org/1943274/2147477734/942-470-50-3

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI https://asc.fasb.org/1943274/2147481112/505-10-50-7

+ Details

Benefit Plans - Schedule of Accumulated and Projected Benefit Obligations (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Pension Benefits
Plans with projected benefit obligation in excess of plan assets:
Projected benefit obligation	$ 43,644	$ 40,328
Fair value of plan assets	0	0
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	40,890	38,053
Fair value of plan assets	0	0
Other Postretirement Benefits
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	15,874	16,891
Fair value of plan assets	$ 10,047	$ 9,844

Lines of Credit - Narrative (Details) $ in Thousands		1 Months Ended	12 Months Ended
Lines of Credit - Narrative (Details) $ in Thousands	Jul. 11, 2025 USD ($)	Aug. 31, 2022 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 12, 2025 USD ($)	Jun. 11, 2025 USD ($)	Aug. 02, 2023	Dec. 31, 2019 USD ($)	Oct. 09, 2019 USD ($)
Line of Credit Facility [Line Items]
Weighted-average interest rate on short-term borrowings			4.75%	6.08%
Repayments of lines of credit			$ 468,821	$ 295,260	$ 134,493
Revolving Credit Facility \| Line of Credit
Line of Credit Facility [Line Items]
Aggregate outstanding balance on lines of credit			86,834	119,124
Unused Portion			283,166
Line Limit			370,000
Revolving Credit Facility \| Line of Credit \| Credit Agreement
Line of Credit Facility [Line Items]
Aggregate outstanding balance on lines of credit			85,000	77,000
Line Limit		$ 300,000				$ 350,000
Debt instrument term		5 years
Capitalization ratio								0.70
Revolving Credit Facility \| Line of Credit \| CTWS Credit Agreement Maturing May 2025
Line of Credit Facility [Line Items]
Aggregate outstanding balance on lines of credit			0	40,000
Unused Portion			0
Line Limit			0							$ 40,000
Repayments of lines of credit	$ 25,000
Revolving Credit Facility \| Line of Credit \| CTWS Credit Agreement Maturing August 2028
Line of Credit Facility [Line Items]
Aggregate outstanding balance on lines of credit			1,834	2,124
Unused Portion			8,166
Line Limit			10,000						$ 10,000	$ 75,000
Revolving Credit Facility \| Line of Credit \| SJWC Credit Agreement Maturing June 2026
Line of Credit Facility [Line Items]
Aggregate outstanding balance on lines of credit			0	$ 0
Unused Portion			10,000
Line Limit			$ 10,000				$ 10,000

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2022		30,801,912
Beginning balance at Dec. 31, 2022	$ 1,110,868	$ 31	$ 651,004	$ 458,356	$ 1,477
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	84,987			84,987
Unrealized gain (loss) on investment, net of tax effect	530				530
Adjustment to pension benefit plans, net of taxes	(216)				(216)
Share-based compensation	4,592		4,647	(55)
Issuance of restricted and deferred stock units (in shares)		67,164
Issuance of restricted and deferred stock units	$ (2,259)		(2,259)
Employee stock purchase plan (in shares)	34,122	34,122
Employee stock purchase plan	$ 2,141		2,141
Common stock issuance, net of costs (in shares)		1,119,806
Issuance of common stock, net of issuance costs	80,659	$ 1	80,658
Dividends paid	(47,905)			(47,905)
Ending balance (in shares) at Dec. 31, 2023		32,023,004
Ending balance at Dec. 31, 2023	1,233,397	$ 32	736,191	495,383	1,791
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	93,967			93,967
Unrealized gain (loss) on investment, net of tax effect	(442)				(442)
Adjustment to pension benefit plans, net of taxes	611				611
Share-based compensation	5,589		5,623	(34)
Issuance of restricted and deferred stock units (in shares)		41,023
Issuance of restricted and deferred stock units	$ (1,212)		(1,212)
Employee stock purchase plan (in shares)	42,853	42,853
Employee stock purchase plan	$ 2,188		2,188
Common stock issuance, net of costs (in shares)		1,522,289
Issuance of common stock, net of issuance costs	85,008	$ 2	85,006
Dividends paid	$ (52,132)			(52,132)
Ending balance (in shares) at Dec. 31, 2024	33,629,169	33,629,169
Ending balance at Dec. 31, 2024	$ 1,366,974	$ 34	827,796	537,184	1,960
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	102,578			102,578
Unrealized gain (loss) on investment, net of tax effect	0
Adjustment to pension benefit plans, net of taxes	(493)				(493)
Share-based compensation	6,407		6,444	(37)
Issuance of restricted and deferred stock units (in shares)		50,366
Issuance of restricted and deferred stock units	$ (989)		(989)
Employee stock purchase plan (in shares)	50,861	50,861
Employee stock purchase plan	$ 2,131		2,131
Common stock issuance, net of costs (in shares)		2,387,846
Issuance of common stock, net of issuance costs	122,808	$ 2	122,806
Dividends paid	$ (58,645)			(58,645)
Ending balance (in shares) at Dec. 31, 2025	36,118,242	36,118,242
Ending balance at Dec. 31, 2025	$ 1,540,771	$ 36	$ 958,188	$ 581,080	$ 1,467

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Schedule of Property, Plant and Equipment

The major components of depreciable plant and equipment as of December 31, 2025 and 2024 are as follows:


	2025		2024
Source of supply	$	243,335	228,621
Pumping plant	331,134		301,280
Water treatment plant	396,061		367,836
Transmission and distribution plant	3,323,482		3,015,978
General plant	394,632		335,599
Total depreciable plant and equipment	$	4,688,644	4,249,314

Depreciation is computed using the straight-line method over the estimated remaining service lives of groups of assets. The estimated service lives of depreciable plant and equipment are as follows:


			Useful Lives
Source of supply			20 to 100 years
Pumping plant			5 to 70 years
Water treatment plant			5 to 62 years
Transmission and distribution plant			10 to 100 years
General plant			5 to 68 years

Property, Plant and Equipment

The major components of nonutility properties and real estate investments are as follows as of December 31:


	2025		2024
Land	$	914	915
Wholesale water supply assets	—		—
Buildings and improvements	769		399

Subtotal	1,683		1,314
Less: accumulated depreciation and amortization	103		98
Total	$	1,580	1,216

Schedule of Estimated Refunds of Advances for Construction and Contributions in Aid of Construction

Estimated refunds for the next five years and thereafter are shown below:


	Estimated Refunds
2026	$	2,569
2027	2,535
2028	2,615
2029	2,592
2030	2,549
Thereafter	45,627

Schedule of Asset Retirement Obligations

As of December 31, 2025 and 2024, the asset retirement obligation is as follows:


	2025			2024
Estimated future retirement costs	$	4,220		4,303
Discount rate	6		%	6	%


Retirement obligation, present value	$	930		887

Schedule of Disaggregation of Revenue

Detail of H2O America’s revenue components are as follows for the years ended December 31:


	2025		2024	2023
Revenue from contracts with customers	$	805,594	736,326	678,168
Alternative revenue programs, net	6,672		6,181	3,634
Other balancing and memorandum accounts and regulatory mechanisms, net	(11,919)		(153)	(17,123)
Rental income	243		6,085	5,684
	$	800,590	748,439	670,363

Accounting Standards Update and Change in Accounting Principle

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2023-09 “Improvements to Income Tax Disclosures”

The ASU was adopted with the annual financial statements for the year ended December 31, 2025.

Prospective, with retrospective application also permitted.

The standard only resulted in updates to disclosure and did not have a material impact on the Company’s financial position and results of operations.

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2024-03 “Disaggregation of Income Statement Expenses”

Prospective, with retrospective application also permitted.

The standard is expected to only result in updates to disclosure and is not expected to have a material impact on the Company’s financial position and results of operations.

ASU 2025-06 “Intangibles-Goodwill and Other-Internal-Use Software (subtopic 350-40)”

The ASU is effective for H2O America for its annual financial statements for the year ending December 31, 2028 and for interim reporting periods for the year ending December 31, 2028.

Prospective, retrospective or on a modified transition approach with early adoption permitted.

H2O America is currently evaluating the impact of ASU 2025-06 on its financial statements and will adopt ASU 2025-06 in fiscal year ended December 31, 2028.

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2025-10 “Government Grants (Topic 832)”

The ASU is effective for H2O America for annual reporting periods beginning after December 15, 2028 and interim reporting periods within those annual reporting periods. Early adoption is permitted.

Retrospective adoption with modified prospective and modified retrospective application also permitted.

H2O America is currently evaluating the impact of ASU 2025-10 on its financial statements and will adopt ASU 2025-10 in fiscal year ended December 31, 2029.

ASU 2025-11 “Interim Reporting (Topic 270)”

The ASU is effective for H2O America for interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted.

Prospective, with retrospective application also permitted.

H2O America is currently evaluating the disclosure impact of ASU 2025-11; however, the standard is not expected to impact the consolidated financial position, results of operations or cash flows.

Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Finite-Lived Intangible Assets

The components of intangible assets as of December 31, 2025 and 2024 are as follows:


	2025		2024
Utility Plant Intangible Assets:
Indefinite-lived water rights	$	28,386	28,386
Purchase premium customer relationships	13,400		13,400

Other intangibles	9,897		9,818
Utility plant intangible assets	51,683		51,604
Less: Accumulated amortization
Purchase premium customer relationships	5,561		4,667

Other intangibles	5,059		4,858
Utility plant net intangible assets	$	41,063	42,079

Equity Plans - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Equity Plans - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Apr. 26, 2023
Option Indexed to Issuer's Equity [Line Items]
Fair value of restricted stock awards	$ 1,478	$ 4,788	$ 4,170
Performance-based and market-based restricted stock awards issued (in shares)	29,413	33,670	15,955
Performance-based and market-based restricted stock awards vested (in shares)	7,805
Performance-based and market-based restricted stock awards outstanding (in shares)	28,598
Employee stock purchase plan (in shares)	50,861	42,853	34,122
Restricted stock and deferred restricted stock
Option Indexed to Issuer's Equity [Line Items]
Share-based payment arrangement, nonvested award, cost not yet recognized, amount	$ 8,939
Period for recognition of compensation cost	1 year 1 month 20 days
Performance Shares \| Minimum
Option Indexed to Issuer's Equity [Line Items]
Range of shares issuable	0.00%
Performance Shares \| Maximum
Option Indexed to Issuer's Equity [Line Items]
Range of shares issuable	150.00%
Market-based RSU \| Minimum
Option Indexed to Issuer's Equity [Line Items]
Range of shares issuable	0.00%
Market-based RSU \| Maximum
Option Indexed to Issuer's Equity [Line Items]
Range of shares issuable	200.00%
Incentive Plan
Option Indexed to Issuer's Equity [Line Items]
Remaining shares available for issuance (in shares)				1,142,000
Incentive Plan \| Restricted stock and deferred restricted stock
Option Indexed to Issuer's Equity [Line Items]
Remaining shares available for issuance (in shares)	862,815
Shares issuable under the plan upon exercise of outstanding awards (in shares)	278,565
Incentive Plan \| Common Stock
Option Indexed to Issuer's Equity [Line Items]
Maximum number of shares per employee (in shares)	600,000
Shares issued pursuant to the plan (in shares)	1,213,202	1,142,770	1,080,759
Shares issuable under the plan upon exercise of outstanding awards (in shares)		191,177	150,704
Employee Stock Purchase Plan
Option Indexed to Issuer's Equity [Line Items]
Purchase price of common stock to employees under the plan, percent	85.00%
Maximum percent of base salary employees can designate for share purchase under the plan	10.00%
Employee Stock Purchase Plan \| Common Stock
Option Indexed to Issuer's Equity [Line Items]
Remaining shares available for issuance (in shares)	406,286
Number of shares reserved for issuance under the plan (in shares)	500,000

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Operating revenue	$ 800,590	$ 748,439	$ 670,363
Production Expenses:
Purchased water	126,343	158,568	135,982
Power	21,769	11,457	9,602
Groundwater extraction charges	112,076	73,146	62,980
Other production expenses	50,973	48,851	47,636
Total production expenses	311,161	292,022	256,200
Administrative and general	125,998	105,830	98,656
Maintenance	32,895	31,301	25,729
Property taxes and other non-income taxes	37,686	35,928	34,475
Depreciation and amortization	115,323	112,855	105,868
Total operating expense	623,063	577,936	520,928
Operating income	177,527	170,503	149,435
Other (expense) income:
Interest on long-term debt and other interest expense	(72,575)	(71,390)	(66,144)
Pension non-service credit (cost)	6,436	3,769	(1,230)
Other, net	3,545	55	8,882
Income before income taxes	114,933	102,937	90,943
Provision for income taxes	12,355	8,970	5,956
Net income	102,578	93,967	84,987
Other comprehensive income:
Unrealized (loss) gain on investment, net of taxes of $0 in 2025, $(163) in 2024 and $166 in 2023	0	(442)	530
Adjustment to pension benefit plans, net of taxes of $0 in 2025, $0 in 2024 and $80 in 2023	(493)	611	(216)
Comprehensive income	$ 102,085	$ 94,136	$ 85,301
Earnings per share
—Basic (in dollars per share)	$ 2.93	$ 2.87	$ 2.69
—Diluted (in dollars per share)	$ 2.92	$ 2.87	$ 2.68
Weighted average shares outstanding
—Basic (shares)	35,002,252	32,701,292	31,575,197
—Diluted (shares)	35,102,487	32,779,573	31,663,274

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2025

Accounting Policies [Abstract]

Consolidation

The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of H2O America, its wholly owned subsidiaries, and one variable interest entity in which one H2O America subsidiary is the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. The accounting policies of H2O America’s subsidiaries comply with the applicable uniform system of accounts prescribed by the respective regulators and conform to generally accepted accounting principles for rate-regulated public utilities.

Use of Estimates

Depreciable Utility Plant and Equipment and Allowance For Funds Used During Construction ("AFUDC")

The cost of utility plant retired (less salvage) is charged to accumulated depreciation and no gain or loss is recognized. To the extent H2O America recovers retirement costs through rates during the life of the associated asset and before the costs are incurred, these amounts result in a regulatory liability being reported based on the amounts previously recovered through customer rates until the costs to retire those assets are incurred.

Allowance For Funds Used During Construction (“AFUDC”)

Intangible Assets

Nonutility Properties and Real Estate Investments

Depreciation on buildings and improvements for real estate investments is computed using the straight-line method over the estimated useful lives of the assets, ranging from 7 to 39 years.

Business Combinations and Asset Acquisitions

Impairment of Long-Lived Assets and Goodwill

Cash and Cash Equivalents

Cash and cash equivalents primarily consisted of cash on deposit with banks and short-term, highly liquid investments with original maturities of three months or less.

Accounts Receivable

Financial Instruments and Investments

Income Taxes

Advances for Construction and Contributions in Aid of Construction

Asset Retirement Obligation

Revenue

Revenue also includes a surcharge collected from regulated customers that is paid to the CPUC. This surcharge is recorded both in operating revenue and administrative and general expenses.

Share-Based Compensation

H2O America utilizes the Monte Carlo valuation model, which requires the use of subjective assumptions, to compute the fair value of market-vesting restricted stock units.

Earnings Per Share

Earnings per Share

Related-Party Transaction

New Accounting Standards

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2023-09 “Improvements to Income Tax Disclosures”

The ASU was adopted with the annual financial statements for the year ended December 31, 2025.

Prospective, with retrospective application also permitted.

The standard only resulted in updates to disclosure and did not have a material impact on the Company’s financial position and results of operations.

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2024-03 “Disaggregation of Income Statement Expenses”

Prospective, with retrospective application also permitted.

The standard is expected to only result in updates to disclosure and is not expected to have a material impact on the Company’s financial position and results of operations.

ASU 2025-06 “Intangibles-Goodwill and Other-Internal-Use Software (subtopic 350-40)”

The ASU is effective for H2O America for its annual financial statements for the year ending December 31, 2028 and for interim reporting periods for the year ending December 31, 2028.

Prospective, retrospective or on a modified transition approach with early adoption permitted.

H2O America is currently evaluating the impact of ASU 2025-06 on its financial statements and will adopt ASU 2025-06 in fiscal year ended December 31, 2028.

Standard

Description

Date of Adoption

Application

Effect on the Consolidated Financial Statements

ASU 2025-10 “Government Grants (Topic 832)”

The ASU is effective for H2O America for annual reporting periods beginning after December 15, 2028 and interim reporting periods within those annual reporting periods. Early adoption is permitted.

Retrospective adoption with modified prospective and modified retrospective application also permitted.

H2O America is currently evaluating the impact of ASU 2025-10 on its financial statements and will adopt ASU 2025-10 in fiscal year ended December 31, 2029.

ASU 2025-11 “Interim Reporting (Topic 270)”

The ASU is effective for H2O America for interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted.

Prospective, with retrospective application also permitted.

H2O America is currently evaluating the disclosure impact of ASU 2025-11; however, the standard is not expected to impact the consolidated financial position, results of operations or cash flows.

Equity Plans - Schedule of Restricted Stock and Deferred Restricted Stock Activity (Details) - Restricted stock and deferred restricted stock - Incentive Plan	12 Months Ended
	Dec. 31, 2025 $ / shares shares
Units
Outstanding, beginning balance (in shares) \| shares	191,177
Granted (in shares) \| shares	175,037
Issued (in shares) \| shares	(70,611)
Forfeited (in shares) \| shares	(17,038)
Outstanding ending balance (in shares) \| shares	278,565
Vested (in shares) \| shares	30,162
Weighted- Average Grant- Date Fair Value
Outstanding, beginning balance (in dollars per share) \| $ / shares	$ 65.36
Granted (in dollars per share) \| $ / shares	48.65
Issued (in dollars per share) \| $ / shares	63.53
Forfeited (in dollars per share) \| $ / shares	58.29
Outstanding, ending balance (in dollars per share) \| $ / shares	52.32
Vested (in dollars per share) \| $ / shares	$ 79.89
Units
Nonvested, beginning balance (in shares) \| shares	159,156
Granted (in shares) \| shares	175,037
Vested (in shares) \| shares	(76,725)
Forfeited (in shares) \| shares	(9,065)
Nonvested, ending balance (in shares) \| shares	248,403
Weighted- Average Grant- Date Fair Value
Nonvested, beginning balance (in dollars per share) \| $ / shares	$ 64.30
Granted (in dollars per share) \| $ / shares	48.65
Vested (in dollars per share) \| $ / shares	68.03
Forfeited (in dollars per share) \| $ / shares	58.29
Nonvested, ending balance (in dollars per share) \| $ / shares	$ 52.34

Intangible Assets

12 Months Ended

Dec. 31, 2025

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

Utility plant intangible assets consist of $28,386 of indefinite-lived water rights, $13,400 related to the purchase premium for customer relationships, and other intangibles of $9,897 as of December 31, 2025. Other intangibles primarily consist of $4,371 for service area expansions by TWC, $1,400 for customer relationships and $1,040 incurred in conjunction with Valley Water water contracts related to the operation of SJWC.

Amortization expense for the intangible assets was $1,095, $1,429 and $1,310 for the years ended December 31, 2025, 2024 and 2023, respectively. Amortization expense for 2026 through 2030 and thereafter is anticipated to be approximately $1,095 per year.

The components of intangible assets as of December 31, 2025 and 2024 are as follows:


	2025		2024
Utility Plant Intangible Assets:
Indefinite-lived water rights	$	28,386	28,386
Purchase premium customer relationships	13,400		13,400

Other intangibles	9,897		9,818
Utility plant intangible assets	51,683		51,604
Less: Accumulated amortization
Purchase premium customer relationships	5,561		4,667

Other intangibles	5,059		4,858
Utility plant net intangible assets	$	41,063	42,079

Intangible Assets - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Utility Plant Intangible Assets:
Intangible assets	$ 51,683	$ 51,604
Utility plant intangible assets	51,683	51,604
Utility plant net intangible assets	41,063	42,079
Purchase premium customer relationships
Utility Plant Intangible Assets:
Intangible assets	13,400	13,400
Accumulated amortization of intangible assets	5,561	4,667
Other intangibles
Utility Plant Intangible Assets:
Intangible assets	9,897	9,818
Accumulated amortization of intangible assets	5,059	4,858
Indefinite-lived water rights
Utility Plant Intangible Assets:
Indefinite-lived water rights	$ 28,386	$ 28,386

Summary of Significant Accounting Policies - Advances for Construction and Contributions in Aid of Construction, Estimated Refunds (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Estimated Refunds of Advances for Construction [Abstract]
2026	$ 2,569
2027	2,535
2028	2,615
2029	2,592
2030	2,549
Thereafter	$ 45,627

Summary of Significant Accounting Policies - Advances for Construction and Contributions in Aid of Construction (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Schedule Of Estimated Refunds Of Advances For Construction [Line Items]
Contract with customer, refund period	40 years
Advances for construction	$ 201,413	$ 155,397
Customer advances for construction, non-refundable	108,311	64,920
Customer advances for construction, refunded on service connections	34,615	31,983
Contract with customer, fair value of advances	$ 51,356	$ 43,718
California
Schedule Of Estimated Refunds Of Advances For Construction [Line Items]
Contract with customer, refund period	40 years
Connecticut
Schedule Of Estimated Refunds Of Advances For Construction [Line Items]
Contract with customer, refund period	15 years
Maine
Schedule Of Estimated Refunds Of Advances For Construction [Line Items]
Contract with customer, refund period	15 years

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Utility plant:
Land	$ 44,600	$ 44,657
Depreciable plant and equipment	4,688,644	4,249,314
Construction work in progress	269,272	179,486
Intangible assets	51,683	51,604
Total utility plant	5,054,199	4,525,061
Less: accumulated depreciation and amortization	1,120,232	1,036,450
Net utility plant	3,933,967	3,488,611
Nonutility properties	1,683	1,314
Less: accumulated depreciation and amortization	103	98
Net nonutility properties	1,580	1,216
Current assets:
Cash and cash equivalents	20,686	11,114
Accounts receivable:
Customers, net of allowances for uncollectible accounts of $722 and $1,172 in 2025 and 2024, respectively	62,471	68,679
Income tax	2,720	5,953
Other	7,710	7,059
Accrued unbilled revenue	68,971	60,847
Prepaid expenses	11,634	10,297
Current regulatory assets	8,315	18,172
Other current assets	8,086	8,593
Total current assets	190,593	190,714
Other assets:
Regulatory assets, less current portion	246,547	224,055
Investments	19,711	18,087
Postretirement benefit plans	80,967	66,422
Goodwill	640,311	640,311
Other	35,890	28,893
Total other assets	1,023,426	977,768
Total assets	5,149,566	4,658,309
Stockholders’ equity:
Common stock, $0.001 par value; authorized 70,000,000 shares in 2025 and 2024; issued and outstanding 36,118,242 shares in 2025 and 33,629,169 shares in 2024	36	34
Additional paid-in capital	958,188	827,796
Retained earnings	581,080	537,184
Accumulated other comprehensive income	1,467	1,960
Total stockholders’ equity	1,540,771	1,366,974
Long-term debt, less current portion	1,866,819	1,706,904
Total capitalization	3,407,590	3,073,878
Current liabilities:
Lines of credit	86,834	119,124
Current portion of long-term debt	23,504	3,648
Accrued groundwater extraction charges, purchased water and power	29,321	25,118
Accounts payable	75,427	56,256
Accrued interest	18,241	17,476
Accrued payroll	19,109	15,193
Current regulatory liabilities	0	1,122
Other current liabilities	20,942	23,236
Total current liabilities	273,378	261,173
Deferred income taxes	307,893	276,043
Advances for construction	201,413	155,397
Contributions in aid of construction	342,697	340,738
Postretirement benefit plans	45,878	45,063
Regulatory liabilities, less current portion	546,797	483,719
Other noncurrent liabilities	23,920	22,298
Commitments and contingencies
Total capitalization and liabilities	$ 5,149,566	$ 4,658,309

Commitments	12 Months Ended
Commitments	Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
Commitments	Commitments SJWC purchases water from Valley Water under terms of a master contract expiring in 2051. Delivery schedules for purchased water are based on a contract year beginning July 1, and are negotiated every three years under terms of the master contract with Valley Water. For the years ended December 31, 2025, 2024 and 2023, SJWC purchased from Valley Water 15.9 billion gallons ($120,322), 17.0 billion gallons ($117,698) and 18.3 billion gallons ($111,173), respectively, of contract water. On June 12, 2024, the Valley Water Board of Directors approved treated water deliveries reflecting the contractual delivery schedule reduced by 23% through June 30, 2025. Based on current prices and estimated deliveries, SJWC is committed to purchase from Valley Water a minimum of 90% of the reduced delivery schedule, or 18.9 billion gallons ($148,795) of water at the current contract water rate of $7.872 million per billion gallons for the year ending December 31, 2026. Additionally, SJWC purchases non-contract water from Valley Water on an “as needed” basis if the water supply is available. SJWC operates the Cupertino municipal water system under a service concession arrangement. The system is adjacent to the SJWC service area and has approximately 4,700 service connections. The original agreement commenced in October 1997 and expired on September 30, 2024. Effective October 2024, SJWC entered into a new 12-year agreement with the City of Cupertino subject to an additional term of eight years if agreed to by the parties. SJWC paid an upfront concession fee of $22.1 million in 2024 and agreed to pay, beginning in 2024, an annual investment rent of $1.8 million, subject to annual adjustment based on a specified construction cost index. The concession fees are amortized as reductions to operating revenue over the applicable contract term and the annual investment rent payments are amortized as reductions to operating revenue over the annual period to which they relate. Under the terms of the agreement, SJWC assumes responsibility for all maintenance and operating costs of the system, while receiving all payments for water service. CWC is able, but under no obligation, to purchase up to one million gallons of water per day from RWA, at the then-current wholesale rates per the agreement, $3.3 million per billion gallons as of December 31, 2025. CWC has an agreement with The MDC to purchase water from MDC to serve the Unionville system. The agreement became effective on October 6, 2000 and has a term of fifty years beginning May 19, 2003, the date the water supply facilities related to the agreement were placed in service. CWC agrees to purchase 0.28 billion gallons of water annually from MDC. The rate charged by the MDC at December 31, 2025 was $3.91 per hundred cubic feet. TWC has multiple long-term contracts with the GBRA. The terms of the agreements expire in 2037, 2040, 2044 and 2050, respectively. The agreements, which are take-or-pay contracts, provide TWC with 7,602 acre-feet per year of water supply from Canyon Lake. The water rate may be adjusted by GBRA at any time, provided they give TWC a 60-day written notice on the proposed adjustment. TWC also has treated water supply agreements with the Lower Colorado River Authority and West Travis County Public Utility Agency expiring in 2059 and 2046, respectively, to provide for 350 acre-feet of water per year from Lake Austin and the Colorado River, respectively, at prices that may be adjusted periodically by the agencies. MWC had an agreement with the Kennebec Water District for potable water service. The agreement had previously been in place for 20 years prior to being renewed on November 7, 2020. The renewal contained an initial term of five years and the ability to renew for up to up to 20 years at Kennebec Water District’s option. In November 2025, the agreement was terminated and MWC transitioned from the previously negotiated rate to a standard tariff rate. MWC guarantees a minimum consumption of 0.05 billion gallons of water annually. Through November 2025, water sales to MWC were billed at a wholesale discount of $0.20 per hundred cubic feet of water below Kennebec Water District's tariffed rates. The current tariff rate was $1.51 per hundred cubic feet as of December 31, 2025. As of December 31, 2025, SJWC had 396 employees, of whom 242 were members of unions. In the final quarter of 2025, SJWC executed three-year bargaining agreements with the International Union of Operating Engineers (“OE”), representing certain employees in the engineering department, and the Utility Workers of America (“UWUA”), representing the majority of all nonadministrative employees at SJWC covering the period from January 1, 2026 through December 31, 2028. The agreements include a 3% wage increase provided in 2026, 3% in 2027 and 4.0% in 2028 for the union employees.

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Dec. 31, 2025
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Regulatory Matters

12 Months Ended

Dec. 31, 2025

Regulated Operations [Abstract]

Regulatory Matters

Regulation

Water Utility Services, excluding non-tariffed activities, are subject to rate regulation based on cost recovery and meets the criteria of accounting guidance for rate-regulated operations under ASC Topic 980, which affects the timing of the recognition of certain revenues and expenses. H2O America’s consolidated financial statements reflect the actions of regulators in the rate-making process. The ratemaking process is intended to provide revenues sufficient to recover normal operating expenses, provide funds for replacement of water infrastructure and produce a fair and reasonable return on stockholder common equity.

Water Utility Services, excluding non-tariffed activities, recognizes regulatory assets for incurred costs that are deemed probable of recovery from customers. Also, Water Utility Services recognizes regulatory liabilities for amounts expected to be refunded to customers in the ratemaking process and for amounts collected in advance of the related expenditures. Regulatory assets or liabilities are also recognized for special revenue programs such as WCMA and WRA in accordance with guidance on alternative revenue programs under ASC Topic 980. Application of ASC Topic 980, including determining whether recovery is probable, requires significant judgment by management and includes assessing evidence that may exist prior to regulatory

authorization, including regulatory rules and decisions, historical ratemaking practices, and other facts and circumstances that would indicate that recovery or refund is probable.

If the regulated utility determines that it is no longer probable that regulatory assets or liabilities would be recovered or refunded through the regulatory process, or if the utility ceased to be subject to rate regulation, the affected regulatory assets and liabilities would be derecognized with a corresponding adjustment to income in the period in which that determination was made.

SJWC has established balancing accounts for the purpose of tracking the under-collection or over-collection associated with expense changes and the revenue authorized by the CPUC to offset those expense changes. SJWC’s Full Cost Balancing Account (“FCBA”) tracks water supply costs and energy consumption. The Monterey Water Revenue Adjustment (“MWRAM”) balancing account tracks the difference between the revenue received for actual metered sales through the tiered volumetric rate and the revenue that would have been received with the same actual metered sales if a uniform rate would have been in effect.

SJWC also maintains memorandum accounts to track impacts due to catastrophic events, certain unforeseen water quality expenses related to new federal and state water quality standards, energy efficiency, water conservation, water tariffs, and other approved activities or as directed by the CPUC. The Water Contamination Litigation Memorandum Account (“WCLMA”) allows SJWC to track net proceeds and costs resulting from water contamination litigation. The WCMA allows SJWC to track lost revenue, net of related water costs, associated with reduced sales due to water conservation and associated calls for water use reduction, both mandatory and voluntary. SJWC records the lost revenue captured in the WCMA balancing accounts, including amounts related to a 20-basis point reduction in the authorized return on equity per the terms of the WCMA. Applicable drought surcharges collected are used to offset the revenue losses tracked in the WCMA. Mandatory water conservation requirements from Santa Clara Valley Water District (“Valley Water”) ended on April 11, 2023, which also ended SJWC’s Mandatory Conservation Plan, that included drought allocations and surcharges. On October 2, 2023, the CPUC approved the continuation of WCMA and Water Conservation Expense Memorandum Account under the voluntary call for conservation effective April 20, 2023. All balancing accounts and memorandum accounts not included for recovery or refund in current customer rates will be reviewed by the CPUC in SJWC’s next general rate case or at the time an individual account balance reaches a threshold of 2% of authorized revenue, whichever occurs first. On December 19, 2024, the CPUC issued General Rate Case Decision No. 24-12-077, which approved a recovery of $15,792 in balancing and memorandum accounts from customers through a 12-month surcharge effective January 1, 2025.

CWC has been authorized by PURA to utilize WRA, a decoupling mechanism, to mitigate risks associated with changes in demand. The WRA is used to reconcile actual water demands with the demands projected in the most recent general rate case and allows the company to implement a surcharge or sur-credit as necessary to recover or refund the revenues approved in the general rate case. The WRA allows the company to defer, as a regulatory asset or liability, the amount by which actual revenues deviate from the revenues allowed in the most recent general rate proceedings.

Regulatory Assets and Liabilities

Regulatory assets and liabilities are comprised of the following as of December 31:


	2025		2024
Regulatory assets:
Income tax temporary differences (a) (q)	$	204,384	180,103
MWRAM (b)	8,553		9,985
Business combinations debt premium (c) (q)	9,772		12,313
Employee benefit costs (d) (q)	5,823		6,370
Catastrophic event memorandum accounts (“CEMA”) (p)	127		986
Revenue adjustment mechanisms (e) (q)	7,931		5,024
Customer Assistance Program (“CAP”) balancing account (f)	3,696		6,599
Water supply costs (i)	847		—
Unrecognized pensions and other postretirement benefits (g) (q)	—		3,177
2022 general rate case interim memorandum account (h)	—		3,392
Other (j)	13,729		14,278
Total regulatory assets	254,862		242,227
Less: current regulatory asset (k)	8,315		18,172
Total regulatory assets, less current portion	$	246,547	224,055
Regulatory liabilities:
Cost of removal (l)	$	394,391	364,398
Future income tax benefits due to customers (m)	82,285		84,128
Unrecognized pensions and other postretirement benefits (g)	32,996		27,872
PFAS legal settlement proceeds (r)	24,682		—
Employee benefit costs (d)	8,771		1,137
Revenue adjustment mechanisms (e)	—		1,122
Water supply costs (i)	—		3,386
Other (n)	3,672		2,798
Total regulatory liabilities	546,797		484,841
Less: current regulatory liabilities (o)	—		1,122
Total regulatory liabilities, less current portion	$	546,797	483,719

___________________________________

(a)Consists primarily of temporary income tax differences that are flowed through to customers, which will be recovered in future rates as these temporary differences reverse. The company expects to recover regulatory assets related to plant depreciation income tax temporary differences over the lives of the plant assets, which are between 5 to 100 years.

(b)MWRAM is described in the previous section.

(c)Consists of debt fair value adjustments recognized through purchase accounting for the completed merger with CTWS in 2019.

(d)Includes deferrals of pension and other postretirement benefit expense, cost of accrued benefits for vacation, and group health insurance.

(e)Consists of WRA and WCMA, which are described in the previous section.

(f)Represents costs associated with SJWC’s CAP.

(g)Represents actuarial losses and gains and prior service cost that have not yet been recognized as components of net periodic benefit cost for certain pension and other postretirement benefit plans.

(h)Represents the difference between revenues collected in interim rates in effect as of January 1, 2022 and revenues that would result from rates authorized in SJWC’s 2022 general rate case retroactive to January 1, 2022.

(i)Reflects primarily SJWC’s FCBA which tracks differences in actual water supply costs compared to amounts assumed in base rates, including applicable changes and variations in costs and quantities that affect the overall mix of the water supply.

(j)Other includes other balancing and memorandum accounts and regulatory mechanisms, deferred costs for certain information technology activities, asset retirement obligations, tank painting, well reconditioning and rate case expenses.

(k)Primarily relates to SJWC’s balancing and memorandum account surcharge in accordance with Decision No. 24-12-077 and the current portion of CWC’s deferred well redevelopment and rate case costs.

(l)Represents amounts collected in rates from customers for estimated costs to retire assets at the end of their expected useful lives before the costs are incurred.

(m)On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the "Tax Act”) was signed into law. The Tax Act included a reduction in the federal income tax rate from 35% to 21%. The rate reduction was effective on January 1, 2018 and resulted in a regulatory liability for the excess deferred income taxes. The benefit of amortization of excess deferred income taxes flows back to the customers under current normalization rules and agreed upon methods with the commissions.

(n)Other includes other balancing and memorandum accounts and regulatory mechanisms, and other regulatory mechanisms.

(o)Primarily relates to the current portion of WRA.

(p)The CPUC has authorized water utilities to activate CEMA accounts in order to track savings and costs related to SJWC’s response to catastrophic events, which includes external labor and materials, increases in bad debt from suspension of shutoffs for non-payment, waived deposits and reconnection fees, and divergence from actual versus authorized usage. The balances primarily relate to expenses associated with SJWC’s response to COVID-19, including bad debt.

(q)Generally not earning a return either by interest on the regulatory asset or as a component of rate base at the allowed rate of return.

(r)Primarily relates to legal settlements received by SJWC and CWC from ongoing PFAS water contamination litigation against manufacturers which will be used to offset future costs incurred, recorded as Contributions in Aid of Construction (“CIAC”), or returned to customers through future rates. WCLMA has been established to track net proceeds and costs resulting from water contamination litigation related to SJWC.

Acquisitions (Details) $ in Thousands			1 Months Ended
Acquisitions (Details) $ in Thousands	Aug. 07, 2025 appraiser	Jul. 07, 2025 USD ($)	Dec. 31, 2025 USD ($)
Quadvest Retail Asset Purchase Agreement
Business Combination [Line Items]
Asset acquisition, consideration transferred		$ 483,600	$ 483,600
Asset acquisition, number of appraisers \| appraiser	3
Quadvest Wholesale Asset Purchase Agreement
Business Combination [Line Items]
Asset acquisition, consideration transferred		$ 56,400

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482573/350-20-50-4

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 47
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-47

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-5

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (f)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Equity Plans

12 Months Ended

Dec. 31, 2025

Share-Based Payment Arrangement [Abstract]

Equity Plans

Common Stock

H2O America’s long-term incentive plans provide employees, non-employee board members or the board of directors of any parent or subsidiary, consultants, and other independent advisors who provide services to the company or subsidiary the opportunity to acquire an equity interest in H2O America. H2O America also maintains stock plans in connection with its acquisition of CTWS which are no longer granting new stock awards. In addition, shares are issued to employees under H2O America’s employee stock purchase plan.

On April 26, 2023, H2O America adopted the successor plans, the 2023 Long-Term Incentive Plan and the 2023 Employee Stock Purchase Plan, to replace the Amended and Restated Long-Term Incentive Plan (the “Predecessor Incentive Plan”) and the 2014 Employee Stock Purchase Plan (the “Predecessor ESPP”), respectively. The Predecessor Incentive Plan terminated on April 23, 2023 and the Predecessor ESPP terminated on July 31, 2023. Each outstanding award under the Predecessor Incentive Plan will remain outstanding under the Predecessor Incentive Plan and shall be governed solely by the terms of the documents evidencing such awards. The 2023 Long-Term Incentive Plan reserves a total of 1,142,000 shares of H2O America’s common

stock for issuance to employees, non-employee board members or the board of directors of any parent or subsidiary, consultants, and other independent advisors who provide services to the H2O America and its subsidiaries. The 2023 Employee Stock Purchase Plan reserves for a total of 500,000 shares of H2O America’s common stock for issuance for eligible employees to purchase common stock at a discount through accumulated payroll deductions. Remaining reserves for both of the predecessor plans were terminated with the adoption of the successor plans.

A participant in the plans generally may not receive plan awards covering an aggregate of more than 600,000 shares of common stock in any calendar year. Additionally, awards granted under the plans may be conditioned upon the attainment of specified Company performance goals. The types of awards included in the plans are restricted stock awards, restricted stock units, performance shares, or other share-based awards. In addition, shares are issued to employees under the employee stock purchase plan (“ESPP”) that was approved by H2O America stockholders.

As of December 31, 2025, 2024 and 2023, 1,213,202, 1,142,770 and 1,080,759 shares have been issued pursuant to the plans, and 278,565, 191,177 and 150,704 shares are issuable upon the vesting of outstanding restricted stock units, performance-based stock units, and deferred restricted stock units for the years ended 2025, 2024 and 2023, respectively. The remaining shares available for issuance under the plans are 862,815 as of December 31, 2025. The compensation costs charged to income is recognized on a straight-line basis over the requisite service period.

A summary of compensation costs charged to income and proceeds from share-based compensation, which are recorded to additional paid-in capital and common stock, by award type, are presented below for the years ended December 31:


	2025		2024	2023
Compensation costs charged to income:
ESPP	$	360	557	378
Restricted stock and deferred restricted stock	6,084		5,066	4,269
Total compensation costs charged to income	$	6,444	5,623	4,647
ESPP proceeds	$	2,131	2,188	2,141

Restricted Stock and Deferred Restricted Stock

A summary of H2O America’s outstanding restricted and deferred restricted stock awards under the Plan as of December 31, 2025, and changes during the year ended December 31, 2025, are presented below:


	Units	Weighted- Average Grant- Date Fair Value
Outstanding as of January 1, 2025	191,177	$	65.36
Granted	175,037	48.65
Issued	(70,611)	63.53
Forfeited	(17,038)	58.29
Outstanding as of December 31, 2025	278,565	$	52.32
Shares vested as of December 31, 2025	30,162	$	79.89

A summary of the status of H2O America’s nonvested restricted and deferred restricted stock awards under the plans as of December 31, 2025, and changes during the year ended December 31, 2025, are presented below:


	Units	Weighted- Average Grant- Date Fair Value
Nonvested as of January 1, 2025	159,156	$	64.30
Granted	175,037	48.65
Vested	(76,725)	68.03
Forfeited	(9,065)	58.29
Nonvested as of December 31, 2025	248,403	$	52.34

Total fair value of restricted stock awards for all plans that were vested for the years ended 2025, 2024 and 2023 were $1,478, $4,788 and $4,170, respectively. As of December 31, 2025, the total unrecognized compensation costs related to restricted and

deferred restricted stock plans amounted to $8,939. This cost is expected to be recognized over a weighted-average period of 1.14 years.

For the years ended December 31, 2025, 2024 and 2023, 29,413, 33,670 and 15,955, respectively, of performance-based and market-based restricted stock awards were issued upon the attainment of certain performance metrics and service-based vesting under the Plan. Based upon actual attainment relative to the target performance metric, the number of shares issuable can range between 0% to 150% of the target number of shares for performance-based restricted stock awards, or between 0% and 200% of the target number of shares for market-based restricted stock awards. As of December 31, 2025, 7,805 performance-based and market-based restricted stock awards vested and 28,598 remained outstanding.

Employee Stock Purchase Plan

The ESPP allows eligible employees to purchase shares of H2O America’s common stock at 85% of the fair value of shares on the purchase date. Under the ESPP, employees can designate up to a maximum of 10% of their base compensation for the purchase of shares of common stock, subject to certain restrictions. A total of 500,000 shares of H2O America’s common stock have been reserved for issuance under the ESPP. The remaining shares available for issuance under the ESPP are 406,286 as of December 31, 2025.

For the year ended December 31, 2025, 2024 and 2023, a total of 50,861, 42,853 and 34,122 shares, respectively, were issued under the ESPP. The plan has no look-back provisions.

Lines of Credit - Schedule of Lines of Credit (Details) - Revolving Credit Facility - Line of Credit - USD ($) $ in Thousands	Dec. 31, 2025	Jun. 11, 2025	Dec. 31, 2024	Dec. 31, 2019	Oct. 09, 2019
Line of Credit Facility [Line Items]
Line Limit	$ 370,000
Amounts Outstanding	86,834		$ 119,124
Unused Portion	283,166
Syndicated Credit Agreement
Line of Credit Facility [Line Items]
Line Limit	350,000
Amounts Outstanding	85,000		77,000
Unused Portion	265,000
H2O America Credit Agreement Maturing September 2030
Line of Credit Facility [Line Items]
Line Limit	50,000
Amounts Outstanding	11,000		3,000
Unused Portion	39,000
SJWC Credit Agreement Maturing September 2030
Line of Credit Facility [Line Items]
Line Limit	165,000
Amounts Outstanding	45,000		44,000
Unused Portion	120,000
CTWS Syndicated Credit Agreement Maturing September 2030
Line of Credit Facility [Line Items]
Line Limit	0
Amounts Outstanding	0		30,000
Unused Portion	0
CWC Credit Agreement Maturing September 2030
Line of Credit Facility [Line Items]
Line Limit	80,000
Amounts Outstanding	13,000		0
Unused Portion	67,000
MWC Credit Agreement Maturing September 2030
Line of Credit Facility [Line Items]
Line Limit	25,000
Amounts Outstanding	0		0
Unused Portion	25,000
SJWTX Credit Agreement Maturing September 2030
Line of Credit Facility [Line Items]
Line Limit	30,000
Amounts Outstanding	16,000		0
Unused Portion	14,000
SJWC Credit Agreement Maturing June 2026
Line of Credit Facility [Line Items]
Line Limit	10,000	$ 10,000
Amounts Outstanding	0		0
Unused Portion	10,000
CTWS Credit Agreement Maturing August 2028
Line of Credit Facility [Line Items]
Line Limit	10,000			$ 10,000	$ 75,000
Amounts Outstanding	1,834		2,124
Unused Portion	8,166
CTWS Credit Agreement Maturing May 2025
Line of Credit Facility [Line Items]
Line Limit	0				$ 40,000
Amounts Outstanding	0		$ 40,000
Unused Portion	$ 0

Long-Term Debt

12 Months Ended

Dec. 31, 2025

Debt Disclosure [Abstract]

Long-Term Debt

Long-term debt as of December 31 was as follows:


Description	Rate	Maturity	2025		2024

H2O America Senior notes (a)	2.47% - 3.53%	2029 - 2039	$	560,000	560,000
SJWC:
Senior notes (a)	3.00% - 7.20%	2026 - 2055	560,000		505,000
California Pollution Control Financing Authority Revenue Bond	4.75%	2046	70,000		70,000
Total SJWC			630,000		575,000
CTWS bank term loans	4.09%, 4.15%	2027, 2037	12,212		14,389
CWC:
Connecticut Innovations Revenue Bonds, variable rate		2028 - 2029	22,050		22,050
Senior notes (a)	3.07% - 6.46%	2037 - 2055	330,000		270,000
State revolving fund loans	2.00%	2044	308		327
Bank term loans	4.04% - 4.75%	2028 - 2036	96,295		96,295
Total CWC			448,653		388,672
TWC:
Senior note (a)	6.27%	2036	15,000		15,000
Bank term loans	4.01% - 6.68%	2041 - 2055	105,000		65,000
Seller financing debt	(b)	2053	29,000		29,000
Total TWC			149,000		109,000

MWC:
State revolving fund loans	0.00% - 2.23%	2026 - 2054	16,336		12,763
Bank term loans	3.89% - 6.47%	2026 - 2055	85,000		60,000
Total MWC			101,336		72,763
Total debt			1,901,201		1,719,824
Unamortized debt premium and discount, net			(1,644)		(56)

Unamortized debt issuance costs			(9,234)		(9,216)
Current portion			(23,504)		(3,648)
Total long-term debt, less current portion			$	1,866,819	1,706,904

___________________________________

(b)Debt does not contain a stated interest rate but is discounted using an effective rate of 5.61%.

The following is a table of the consolidated company’s schedule of principal payments:


Year
2026	$	23,950
2027	3,207
2028	44,699
2029	325,624
2030	53,201
Thereafter	1,450,520

The estimated fair value of long-term debt as of December 31, 2025 and 2024 was $1,716,589 and $1,490,024, respectively, and was determined using a discounted cash flow analysis, based on the current rates for similar financial instruments of the

same duration and creditworthiness of the company. As of December 31, 2025, $1,715,635 of the total fair value of long-term debt would be categorized as Level 2 in the fair value hierarchy, and $954 would be categorized as Level 3. As of December 31, 2024, $1,473,393 of the total fair value of long-term debt was categorized as Level 2 in the fair value hierarchy, and $16,631 was categorized as Level 3.

SJWC

On July 31, 2024, SJWC entered into and closed a note purchase agreement with certain institutional investors, pursuant to which the company sold an aggregate principal amount of $75,000 of its 5.63% Senior Notes, Series Q (“Series Q Notes”). The Series Q Notes are unsecured obligations of SJWC and are due on July 31, 2054. Interest is payable semi-annually in arrears on January 31st and July 31st of each year.

On November 12, 2025, SJWC entered into a note purchase agreement with certain institutional investors, pursuant to which the company sold an aggregate principal amount of $55,000 of its 5.83% Senior Notes, Series R (“Series R Notes”). The Series R Notes are unsecured obligations of SJWC and are due on November 1, 2055. Interest is payable semi-annually in arrears on May 1st and November 1st of each year, commencing May 1, 2026.

CWC

On July 31, 2024, CWC entered into a note purchase agreement with certain institutional investors, pursuant to which the company sold an aggregate principal amount of $50,000 of its 5.78% Senior Notes, Series 2024 (“Series 2024 Notes”). The Series 2024 Notes are unsecured obligations of CWC and are due on July 31, 2054. Interest is payable semi-annually in arrears on January 31st and July 31st of each year. The closing of the notes purchase agreement occurred in August 2024.

On October 28, 2025, CWC entered into a note purchase agreement with certain institutional investors, pursuant to which the company agreed to sell an aggregate principal amount of $60,000 of its 6.08% Senior Notes, Series 2025 (“Series 2025 Notes”). The Series 2025 Notes are unsecured obligations of CWC and are due on November 1, 2055. Interest is payable semi-annually in arrears on May 1st and November 1st of each year, commencing May 1, 2026.

TWC and TWR

In August 2023, TWR closed on an asset acquisition that included an obligation for a post-closing production payment of $29,000 to the seller over a period of up to 29 years. The repayment schedule is based on the quantity of groundwater produced from the acquired wells, subject to certain provisions in the purchase agreement. The difference between the gross obligation of $29,000 and the fair value at the date of acquisition is reflected as a debt discount and is being amortized as interest expense using the effective interest method over the life of the obligation. During the third quarter of 2024, TWC assumed the obligation in connection with an asset purchase agreement pursuant to which TWC acquired all of the net assets of TWR.

On December 6, 2024, TWC issued a promissory note to CoBank under an existing master loan agreement for a principal amount of $20,000 at a fixed interest rate of 6.47%. This note is an unsecured obligation of TWC due on November 20, 2054. Interest is payable quarterly in arrears on the 20th day of January, April, July and October of each year. In January 2025, TWC amended the existing master loan agreement to modify one of the financial covenants. All of the other terms and conditions remain the same.

On September 18, 2025, TWC issued a promissory note to a CoBank under an existing master loan agreement for a principal amount of $40,000 at a fixed interest rate of 6.68%. This note is an unsecured obligation of TWC due on September 1, 2055. Interest is payable quarterly in arrears on the 20th day of January, April, July and October of each year.

MWC

MWC finances a portion of its capital improvement program through loans under state revolving fund programs, including the Safe Drinking Water Revolving Fund (“SDWSRF”). In 2024, MWC obtained MPUC approval to issue two First Mortgage Bonds through the Maine Municipal Bond Bank. The Series X Bond totaled $3,330, inclusive of $598 of principal forgiveness, resulting in a net loan of $2,732; the issuance was approved on August 22, 2024 and completed on October 1, 2024. The Series Y Bond totaled $3,596, inclusive of $1,258 of principal forgiveness, resulting in a net loan of $2,337; the issuance was approved on August 22, 2024 and completed on November 1, 2024. Each bond constitutes an unsecured obligation of MWC, with the Series X Bond maturing on April 1, 2044 and the Series Y Bond maturing on April 1, 2054, and each bears a fixed interest rate of 1%. Interest is payable semi-annually in arrears on April 1 and October 1, commencing April 1, 2025.

On December 6, 2024, MWC issued a promissory note to CoBank under an existing master loan agreement for a principal amount of $15,000 at a fixed interest rate of 6.47%. This note is an unsecured obligation of MWC due on November 20, 2054. Interest is payable quarterly in arrears on the 20th day of January, April, July and October of each year.

On May 23, 2025, MWC submitted an application with the MPUC seeking approval to issue unsecured notes in an amount up to $25,000. The MPUC granted approval on June 17, 2025. On July 10, 2025, MWC issued a promissory note to CoBank under

an existing master loan agreement for a principal amount of $25,000 at a fixed interest rate of 6.70%. The note is an unsecured obligation of MWC due on July 20, 2055. Interest is payable quarterly in arrears on the 20th day of January, April, July and October of each year.

Financial Covenants

The debt and credit agreements of H2O America and its subsidiaries contain various financial and other covenants. Non-compliance with these covenants could result in accelerated due dates and termination of the agreements. In addition, the credit agreements contain customary representations and warranties and are subject to customary events of default, which may result in outstanding notes becoming immediately due and payable. As of December 31, 2025, H2O America and its subsidiaries were in compliance with all covenants related to its long-term debt agreements.

Benefit Plans - Narrative (Details) - USD ($)	12 Months Ended
Benefit Plans - Narrative (Details) - USD ($)	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Adjustment to pension benefit plans, net of taxes	$ 493,000	$ (611,000)	$ 216,000
Value of life insurance contracts	4,852,000	4,294,000
Annual maximum contribution limit under Health Care Spending Account plan	3,300
Annual maximum contribution limit under Dependent Care Spending Account plan	5,000
Employer contributions to deferral plan	$ 4,928,000	4,221,000	3,902,000
Health care cost trend rate assumed, next fiscal year	8.00%
Ultimate health care cost trend rate	4.50%
Actuarial gain (loss), discount rate change	$ (4,219,000)	21,129,000
Actuarial gain (loss), data and other changes	873,000	(6,005,000)
Defined benefit plan, accumulated benefit obligation	269,908,000	263,607,000
Regulatory assets	0
Estimated required and discretionary employer cash contributions	7,682,000
Unrecognized pensions and other postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Regulatory liabilities	32,996,000	27,872,000
Other comprehensive income (loss), defined benefit plan, gain (loss) arising during period	32,996,000	27,872,000
Unrecognized pensions and other postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Regulatory assets		3,177,000
Other comprehensive income (loss), defined benefit plan, gain (loss) arising during period		(3,150,000)
Other comprehensive (income) loss, defined benefit plan, prior service cost (credit)		27,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	293,142,000	287,044,000	297,834,000
Net periodic pension cost	608,000	3,205,000	8,588,000
Total investments made to fund SERP	5,675,000	8,007,000
Executive Supplemental Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	43,644,000	40,328,000
Net periodic pension cost	3,212,000	3,879,000	3,257,000
Adjustment to pension benefit plans, net of taxes	(493,000)	169,000	$ 314,000
Total investments made to fund SERP	$ 7,887,000	$ 7,336,000
Minimum
Defined Benefit Plan Disclosure [Line Items]
Period for performance standards	3 years
Minimum \| Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, expected return on plan assets	6.50%	6.25%	6.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Period for performance standards	5 years
Maximum \| Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost, expected return on plan assets	6.75%	6.75%	6.75%
TWC Employees
Defined Benefit Plan Disclosure [Line Items]
Interest credits assumption rate	4.25%
TWC Employees \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Interest credits rate	3.25%
TWC Employees \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Interest credits rate	6.00%
CTWS Employees
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase to company sponsored savings plan	3.00%
Executives and Non-employee Directors \| Deferred compensation arrangement with individual, by type of compensation, pension and other postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Deferrals by executives and non-employee directors	$ 8,767,000	$ 8,216,000
Executives and Non-employee Directors \| Deferred compensation arrangement with individual, by type of compensation, pension and other postretirement benefits \| CWC
Defined Benefit Plan Disclosure [Line Items]
Deferrals by executives and non-employee directors	$ 6,552,000	$ 6,276,000

Regulatory Matters - Narrative (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 19, 2024	Dec. 31, 2025
Regulated Operations [Abstract]
Reduction in authorized return of equity		0.20%
Authorized revenue, threshold percentage		2.00%
Balancing and memorandum revenue account, refunds (collections)	$ 15,792

Income Taxes

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Income Taxes

The components of income tax expense were:


	2025		2024	2023
Current:
Federal	$	5,276	(1,828)	10,185
State	1,896		443	4,281
Deferred:
Federal	5,360		11,063	(8,871)
State	(177)		(708)	361
	$	12,355	8,970	5,956


	2025 (a)				2024	2023
Income tax at federal statutory rate	$	24,136	21.0	%	21,617	19,098
Increase (decrease) in taxes attributable to:
State and local income taxes, net of federal income tax effect (b)	1,326		1.2	%	6,488	6,001

Tax credits	(208)		(0.2)	%	—	—
Nontaxable or nondeductible items	543		0.5	%	—	—
Changes in unrecognized tax benefits	331		0.3	%	(1,053)	(4,330)
Property flow-through	—		—	%	(14,793)	(9,045)


Pension flow-through	—		—	%	(530)	(597)
Stock-based compensation	—		—	%	192	(491)
Other adjustments:
Impact of rate regulation
Flow-through	(11,933)		(10.4)	%	—	—
Reversal of excess deferred taxes recognized in regulatory liability	(1,517)		(1.3)	%	(3,227)	(3,625)

Other items	(323)		(0.3)	%	276	(1,055)
	$	12,355	10.8	%	8,970	5,956

(b)Majority of the tax expense reported in this category relates to California. State flow-through adjustments are included in this category for the year ended December 31, 2025.

The components of the net deferred tax liability as of December 31 were as follows:


	2025		2024
Deferred tax assets:
Advances and contributions	$	28,183	26,744
Unamortized investment tax credit	1,141		1,061
Pensions, postretirement benefits and stock-based compensation	11,749		12,529
Debt premium, net	2,734		3,446
California franchise tax	257		503

Deferred revenue	—		—
Tax related regulatory liability	22,572		23,112
Other	9,560		6,337


Total deferred tax assets	76,196		73,732
Deferred tax liabilities:
Utility plant	304,002		277,085
Pension and postretirement	9,272		9,068
Deferred gain and other-property	608		608
Regulatory asset - business combinations debt premium, net	2,734		3,446
Intangibles	2,193		2,443
Deferred revenue	2,330		1,418
Tax related regulatory asset	57,503		50,728


Other	5,447		4,979
Total deferred tax liabilities	384,089		349,775
Net deferred tax liabilities	$	307,893	276,043

Management evaluates the realizability of deferred tax assets based on all available evidence, both positive and negative. The realization of deferred tax assets is dependent on our ability to generate sufficient future taxable income during periods in which the deferred tax assets are expected to reverse. Based on all available evidence, management believes it is more likely than not that H2O America will realize the benefits of its deferred tax assets. Net operating loss carryforwards expire beginning in 2032 and ending in 2043. As of December 31, 2025, the estimated amount of net operating loss carryforwards available to offset future taxable income for Connecticut purposes is $20,739. The estimated state tax credit carryforwards are $907, which will expire beginning in 2028 and ending in 2049.

The change in the net deferred tax liabilities of $31,850 included non-cash items primarily consisting of regulatory assets and liabilities relating to income tax temporary differences.

The total amount of unrecognized tax benefits, before the impact of deductions for state taxes, excluding interest and penalties was $4,094 and $3,707 as of December 31, 2025 and 2024, respectively. The amount of tax benefits, net of any federal benefits for state taxes that would impact the effective rate, if recognized, is approximately $3,514 and $3,150 as of December 31, 2025 and 2024, respectively.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:


	2025		2024	2023
Balance at beginning of year	$	3,707	4,511	9,004
Increase related to tax positions taken during the current year	663		658	231
Increase related to tax positions taken during a prior year	113		380	364
Reductions related to statute expiration	(389)		(1,701)	(1,191)
Reductions related to tax positions taken in a prior year	—		(141)	(3,897)

Balance at end of year	$	4,094	3,707	4,511

The decrease in gross unrecognized tax benefits in 2023 was primarily due to the release of uncertain tax position reserve relating to repairs tax deductions. In April 2023, the IRS issued additional tax guidance that has allowed H2O America to revisit certain historical income tax reserves. Pursuant to the issuance of this guidance, which provided additional clarification regarding some of the uncertain tax areas, the company re-evaluated the risk relating to repair deductions. The result of the analysis led to a release of uncertain tax position reserve. The release relates to repairs expenditures which are more likely than not to be sustained on audit. The net release due to re-evaluation of the reserve was $3,125.

H2O America’s policy is to classify interest and penalties associated with unrecognized tax benefits, if any, in tax expense. Accrued interest expense, net of the benefit of tax deductions which would be available on the payment of such interest, is approximately $283 as of December 31, 2025. H2O America has not accrued any penalties for unrecognized tax benefits. The amount of interest recognized in 2025 was a decrease to expense of $33.

H2O America files U.S. federal income tax returns and income tax returns in various states and is subject to ordinary statute of limitation of three years for federal and three or four years for different state returns. However, due to tax attribute carryforwards, H2O America is subject to examination for tax years 2012 forward for state returns of CTWS and its subsidiaries. The statute of limitations for H2O America returns is closed for these extended years and remains open for 2022 and forward for federal and 2021 or 2022 and forward for different states.

Income Taxes paid (net of refunds) for the year ending December 31, 2025 were as below:


	2025
Federal	$	2,000
State	1,238
Foreign	—
Total	$	3,238

Income Taxes paid (net of refunds) exceeded 5% of total income taxes paid (net of refunds) in the following jurisdictions:


State:	2025
California	$	400
Connecticut	521
Maine	*
Tennessee	219
Texas	*
Total	$	1,140

*Jurisdiction below the threshold for the period presented

On July 4, 2025, Public Law No. 119-21, referred to as the One Big Beautiful Bill Act (“OBBBA”), was signed into law. The OBBBA contains several changes to corporate taxation including the extension of key provisions of the 2017 Tax Cuts and Jobs Act. The legislation has multiple effective dates, with certain provisions effective in 2025 and others phased in through tax year 2027. The legislation may be subject to further clarification and the issuance of interpretive guidance. The Company evaluated the impact of the OBBBA tax legislation for the year ended December 31, 2025, and the impact was not material to the provision for income taxes and deferred tax balances.

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 740
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477617/942-740-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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-Name Accounting Standards Codification
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-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 1
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-URI https://asc.fasb.org/1943274/2147478822/944-740-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 5: http://www.xbrl.org/2003/role/exampleRef
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-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 12C
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12C

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12B

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477891/740-270-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 1
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-URI https://asc.fasb.org/1943274/2147479360/740-10-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-13

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/740/tableOfContent

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-14

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-21

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

FINANCIAL STATEMENT SCHEDULE - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating activities:
Net income	$ 102,578	$ 93,967	$ 84,987
Adjustments to reconcile net income to net cash used in operating activities:
Deferred income taxes	5,183	10,355	(8,510)
Stock-based compensation	6,444	5,623	4,647
Changes in operating assets and liabilities, net of acquired assets and liabilities:
Accounts payable and other current liabilities	9,280	4,241	492
Tax payable and other accrued taxes	(18,280)	(18,355)	(22,415)
Proceeds from litigation settlement, net	7,823	0	0
Other changes, net	(11,254)	7,529	218
Net cash provided by operating activities	244,803	195,526	190,831
Investing activities:
Net cash used in investing activities	(520,101)	(340,095)	(322,272)
Financing activities:
Borrowings from lines of credit	436,530	242,000	146,415
Repayments of lines of credit	(468,821)	(295,260)	(134,493)
Issuance of common stock, net of issuance costs	122,808	85,008	80,659
Proceeds from litigation settlement, net	16,949	0	0
Dividends paid	(58,645)	(52,132)	(47,905)
Net cash provided by financing activities	284,870	145,960	128,820
Net change in cash and cash equivalents	9,572	1,391	(2,621)
Cash and cash equivalents, beginning of year	11,114	9,723	12,344
Cash and cash equivalents, end of year	20,686	11,114	9,723
Cash paid (refunded) during the year for:
Interest	72,093	69,744	64,608
Income taxes	3,238	(598)	23,020
H2O America
Operating activities:
Net income	102,578	93,967	84,987
Adjustments to reconcile net income to net cash used in operating activities:
Earnings from investment in subsidiaries	(117,666)	(108,918)	(95,808)
Deferred income taxes	(1,644)	(618)	718
Stock-based compensation	842	687	696
Changes in operating assets and liabilities, net of acquired assets and liabilities:
Accounts payable and other current liabilities	1,329	1,724	281
Intercompany receivables	(18,387)	(652)	(6,018)
Tax payable and other accrued taxes	14,761	452	1,550
Accrued interest	34	(31)	47
Return on capital from investments in subsidiaries	59,400	90,600	50,550
Proceeds from litigation settlement, net	0	0	0
Other changes, net	(2,677)	532	607
Net cash provided by operating activities	38,570	77,743	37,610
Investing activities:
Proceeds to subsidiaries for notes receivable	(237,246)	(173,374)	(148,392)
Repayments from subsidiaries for notes receivable	208,585	169,001	91,740
Investments in subsidiaries	(84,037)	(97,000)	(25,500)
Net cash used in investing activities	(112,698)	(101,373)	(82,152)
Financing activities:
Borrowings from subsidiaries for notes payable	1,121	27,098	700
Repayments to subsidiaries for notes payable	(155)	(28,824)	(3,140)
Borrowings from lines of credit	133,000	35,000	10,000
Repayments of lines of credit	(125,000)	(42,000)	0
Issuance of common stock, net of issuance costs	122,808	85,008	80,659
Proceeds from litigation settlement, net	0	0	0
Debt issuance costs	(132)	(82)	(46)
Dividends paid	(58,645)	(52,132)	(47,905)
Net cash provided by financing activities	72,997	24,068	40,268
Net change in cash and cash equivalents	(1,131)	438	(4,274)
Cash and cash equivalents, beginning of year	1,306	868	5,142
Cash and cash equivalents, end of year	175	1,306	868
Cash paid (refunded) during the year for:
Interest	17,713	17,919	17,465
Income taxes	(9,676)	0	(4,870)
Supplemental disclosure of non-cash activities:
Share-based compensation from investment in subsidiaries	$ 6,707	$ 5,879	$ 3,778

Summary of Significant Accounting Policies - Nonutility Properties and Real Estate Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Components of Real Estate Investments [Abstract]
Land	$ 914	$ 915
Wholesale water supply assets	0	0
Buildings and improvements	769	399
Subtotal	1,683	1,314
Less: accumulated depreciation and amortization	103	98
Net nonutility properties	$ 1,580	$ 1,216
Building and Building Improvements \| Minimum
Components of Real Estate Investments [Abstract]
Estimated useful life	7 years
Building and Building Improvements \| Maximum
Components of Real Estate Investments [Abstract]
Estimated useful life	39 years

Benefit Plans - Schedule of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 6,571	$ 6,662	$ 7,569
Interest cost	15,600	14,451	14,234
Expected return on assets	(19,777)	(17,852)	(15,440)
Amortization of prior service cost	15	15	15
Amortization of actuarial (gain) loss	(1,801)	(71)	2,210
Recognition of significant event	0	0	0
Net periodic benefit cost	608	3,205	8,588
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	624	665	638
Interest cost	1,351	1,181	1,268
Expected return on assets	(1,179)	(1,068)	(860)
Amortization of prior service cost	0	0	0
Amortization of actuarial (gain) loss	(856)	(643)	(350)
Recognition of significant event	0	0	0
Net periodic benefit cost	$ (60)	$ 135	$ 696

Contingencies	12 Months Ended
Contingencies	Dec. 31, 2025
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies H2O America and its subsidiaries are subject to ordinary routine litigation incidental to its business. In October 2023, CWC, a subsidiary of H2O America, was named as a defendant in a putative class action lawsuit alleging that the water provided by CWC contained contaminants. The case is currently pending in the State of Connecticut Superior Court. CWC is vigorously defending itself in this lawsuit. H2O America is unable to provide a reasonable estimate of loss, if any, at this time. SJWC and CWC are plaintiffs in a lawsuit against manufacturers and/or sellers of PFAS compounds for damages, contribution and reimbursement of costs incurred and continuing to be incurred to address the presence of such PFAS compounds in public water supply systems owned and operated by these utility subsidiaries and throughout their respective service areas. The lawsuit is part of Multi-District Litigation (“MDL”), that commenced on December 7, 2018, in the United States District Court for the District of South Carolina. MWC has submitted timely claims as a settlement class member. On February 8, 2024, the MDL court approved settlements involving defendants The Chemours Company, Corteva, Inc., and DuPont de Nemours, Inc. to resolve claims brought in the MDL against them by public water systems, including SJWC and CWC. On March 29, 2024, the MDL court approved a similar settlement involving defendant 3M Company. On November 22, 2024, the MDL court approved settlements involving defendants Tyco Fire Products LP, and BASF Corporation. H2O America is entitled to a portion of the settlements and is monitoring and evaluating the ongoing litigation and settlement activity with the PFAS defendants for potential impacts to the various claims that these utility subsidiaries have asserted. For the year ended December 31, 2025, the Company received cash proceeds of $25.1 million, in connection with legal settlements with 3M Company and DuPont de Nemours, Inc. related to PFAS contamination. The proceeds were allocated as follows: SJWC received $17 million; CWC received $7.6 million; and MWC received $0.5 million, which includes $0.3 million payable to contract operators. The proceeds are compensatory in nature and are intended to compensate the Company for costs incurred, or to be incurred, to address the presence of PFAS compounds in public water supply systems or to be refunded to customers through rate reductions, and have been recorded as a regulatory liability subject to regulatory approval. H2O America is entitled to receive additional cash proceeds from 3M Company in the subsequent eight years, pursuant to the terms of the settlement agreement. In addition, the Company is party to class action settlements with Tyco Fire Products LP and BASF Corporation. H2O America is monitoring and evaluating the ongoing litigation and settlement activity with the PFAS defendants for potential impacts to the various claims that these utility subsidiaries have asserted. However, the amount of any additional proceeds is not estimable as of the date of this filing.

- Definition

The entire disclosure for loss and gain contingencies. Describes any existing condition, situation, or set of circumstances involving uncertainty as of the balance sheet date (or prior to issuance of the financial statements) as to a probable or reasonably possible loss incurred by an entity that will ultimately be resolved when one or more future events occur or fail to occur, and typically discloses the amount of loss recorded or a range of possible loss, or an assertion that no reasonable estimate can be made.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-URI https://asc.fasb.org/1943274/2147483359/720-20-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 450
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+ Details

Subsequent Event	12 Months Ended
Subsequent Event	Dec. 31, 2025
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event None.

VALUATION AND QUALIFYING ACCOUNTS AND RESERVES

12 Months Ended

Dec. 31, 2025

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

VALUATION AND QUALIFYING ACCOUNTS AND RESERVES

H2O America and Subsidiaries

FINANCIAL STATEMENT SCHEDULE

Schedule II

VALUATION AND QUALIFYING ACCOUNTS AND RESERVES

Years ended December 31, 2025, 2024 and 2023

(in thousands)


Description	2025		2024	2023
Allowance for doubtful accounts:
Balance, beginning of period	$	1,172	6,551	5,753

(Credited) charged to expense	3,636		(1,338)	3,594
(Credited) charged to regulatory asset	—		(3,960)	1,628
Accounts written off	(5,179)		(3,874)	(5,479)
Recoveries of accounts written off	1,093		3,793	1,055
Balance, end of period	$	722	1,172	6,551
Reserve for litigation and claims:
Balance, beginning of period	$	615	1,888	1,768
Charged to expense	97		206	971
Revision to accrual, due to settlements	114		(39)	(166)
Payments	(411)		(1,440)	(685)
Balance, end of period	$	415	615	1,888

Summary of Significant Accounting Policies - Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Revenue from contracts with customers	$ 805,594	$ 736,326	$ 678,168
Alternative revenue programs, net	6,672	6,181	3,634
Other balancing and memorandum accounts and regulatory mechanisms, net	(11,919)	(153)	(17,123)
Rental income	243	6,085	5,684
Operating revenue	800,590	748,439	670,363
Regulated operating revenue, water surcharge	$ 3,927	$ 3,668	$ 4,085

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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+ Details

Income Taxes - Schedule of Income Taxes Paid (Net of Refunds) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Paid, by Individual Jurisdiction [Line Items]
Federal	$ 2,000
State	1,238
Foreign	0
Income taxes	3,238	$ (598)	$ 23,020
State And Local Jurisdiction, Material Amount
Income Tax Paid, by Individual Jurisdiction [Line Items]
State	1,140
California
Income Tax Paid, by Individual Jurisdiction [Line Items]
State	400
Connecticut
Income Tax Paid, by Individual Jurisdiction [Line Items]
State	521
Tennessee
Income Tax Paid, by Individual Jurisdiction [Line Items]
State	$ 219

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2023	Dec. 31, 2024
Income Tax Contingency [Line Items]
Change in net deferred tax liabilities	$ 31,850
Unrecognized tax benefits before impact of deductions for state taxes, excluding interest and penalties	4,094		$ 3,707
Unrecognized tax benefits that would impact effective tax rate	3,514		$ 3,150
Unrecognized tax benefits, decrease resulting from re-evaluation of reserve		$ 3,125
Accrued interest, expense net of the benefit of tax deductions	283
Cumulative reduction in unrecognized tax benefits, due to lapsing of statutes of limitations	33
State
Income Tax Contingency [Line Items]
Operating loss carryforwards	20,739
Tax credit carryforward	$ 907

Contingencies (Details) $ in Millions	12 Months Ended
Contingencies (Details) $ in Millions	Dec. 31, 2025 USD ($)
Loss Contingencies [Line Items]
Proceeds from legal settlements	$ 25.1
Receivable period for noncurrent cash proceeds receivable form legal settlement	8 years
SJWC
Loss Contingencies [Line Items]
Proceeds from legal settlements	$ 17.0
CWC
Loss Contingencies [Line Items]
Proceeds from legal settlements	7.6
MWC
Loss Contingencies [Line Items]
Proceeds from legal settlements	0.5
Settlement payable to contract operators	$ 0.3

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

Long-Term Debt - Schedule of Maturities of Long-term Debt (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Debt Disclosure [Abstract]
2026	$ 23,950
2027	3,207
2028	44,699
2029	325,624
2030	53,201
Thereafter	$ 1,450,520

Segment Reporting (Tables)

12 Months Ended

Dec. 31, 2025

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

Certain allocated assets, such as goodwill, revenue and expenses have been included in the reportable segment amounts. Certain corporate costs and expenses are not allocated to Water Utility Services or Other Services and are shown separately to reconcile to the applicable consolidated amounts.


	For the year ended December 31, 2025
	Reportable Segment
	Water Utility Services		Other Services (1)	Unallocated Corporate (2)	Consolidated
Operating revenue	$	787,099	13,491	—	800,590

Less:
Production expenses	305,460		5,701	—	311,161
Administrative and general	119,665		1,306	5,027	125,998
Maintenance	30,124		2,771	—	32,895
Property taxes and other non-income taxes	37,521		47	118	37,686
Depreciation and amortization	114,286		121	916	115,323
Interest on long-term debt and other interest expense	51,463		—	21,112	72,575

Provision (benefit) for income taxes	19,928		1,371	(8,944)	12,355
Other (3)	(6,531)		(587)	(2,863)	(9,981)
Net income (loss)	$	115,183	2,761	(15,366)	102,578

Capital expenditures	$	519,753	—	—	519,753


	For the year ended December 31, 2024
	Reportable Segment
	Water Utility Services		Other Services (1)	Unallocated Corporate (2)	Consolidated
Operating revenue	$	732,580	15,859	—	748,439

Less:
Production expenses	286,763		5,259	—	292,022
Administrative and general	97,420		2,632	5,778	105,830
Maintenance	29,249		2,052	—	31,301
Property taxes and other non-income taxes	35,223		317	388	35,928
Depreciation and amortization	111,709		253	893	112,855
Interest on long-term debt and other interest expense	47,485		521	23,384	71,390

Provision (benefit) for income taxes	17,134		1,569	(9,733)	8,970
Other (3)	(920)		191	(3,095)	(3,824)
Net income (loss)	$	108,517	3,065	(17,615)	93,967

Capital expenditures	$	377,208	29	—	377,237


	For the year ended December 31, 2023
	Reportable Segment
	Water Utility Services		Other Services (1)	Unallocated Corporate (2)	Consolidated
Operating revenue	$	652,045	18,318	—	670,363

Less:
Production expenses	251,898		4,302	—	256,200
Administrative and general	93,255		2,777	2,624	98,656
Maintenance	23,972		1,757	—	25,729
Property taxes and other non-income taxes	33,469		926	80	34,475
Depreciation and amortization	104,329		646	893	105,868
Interest on long-term debt and other interest expense	42,743		329	23,072	66,144

Provision (benefit) for income taxes	11,293		2,213	(7,550)	5,956
Other (3)	(4,279)		(121)	(3,252)	(7,652)
Net income (loss)	$	95,365	5,489	(15,867)	84,987

Capital expenditures	$	288,627	24,244	—	312,871

___________________________________

(2) The “Unallocated Corporate” category includes the accounts of H2O America, H2O America NE LLC, H2O America TX Holdings, Inc., CTWS, NWU on a stand-alone basis.

(3) Primarily comprised of pension non-service credit (cost) and items of miscellaneous non-operating income (expense).

H2O America’s assets for the Water Utility Services reportable segment and all other are as follows as of December 31:


	2025		2024
Water Utility Services (reportable segment)	$	5,054,235	4,567,182
Other Services	26,707		25,053
Unallocated Corporate	68,624		66,074
Total assets	$	5,149,566	4,658,309

Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of year	$ 3,707	$ 4,511	$ 9,004
Increase related to tax positions taken during the current year	663	658	231
Increase related to tax positions taken during a prior year	113	380	364
Reductions related to statute expiration	(389)	(1,701)	(1,191)
Reductions related to tax positions taken in a prior year	0	(141)	(3,897)
Balance at end of year	$ 4,094	$ 3,707	$ 4,511

Segment Reporting - Reportable Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Operating revenue	$ 800,590	$ 748,439	$ 670,363
Less:
Production expenses	311,161	292,022	256,200
Administrative and general	125,998	105,830	98,656
Maintenance	32,895	31,301	25,729
Property taxes and other non-income taxes	37,686	35,928	34,475
Depreciation and amortization	115,323	112,855	105,868
Interest on long-term debt and other interest expense	72,575	71,390	66,144
Provision (benefit) for income taxes	12,355	8,970	5,956
Other	(9,981)	(3,824)	(7,652)
Net income	102,578	93,967	84,987
Capital expenditures	519,753	377,237	312,871
Assets	5,149,566	4,658,309
Operating Segments \| Water Utility Services
Segment Reporting Information [Line Items]
Operating revenue	787,099	732,580	652,045
Less:
Production expenses	305,460	286,763	251,898
Administrative and general	119,665	97,420	93,255
Maintenance	30,124	29,249	23,972
Property taxes and other non-income taxes	37,521	35,223	33,469
Depreciation and amortization	114,286	111,709	104,329
Interest on long-term debt and other interest expense	51,463	47,485	42,743
Provision (benefit) for income taxes	19,928	17,134	11,293
Other	(6,531)	(920)	(4,279)
Net income	115,183	108,517	95,365
Capital expenditures	519,753	377,208	288,627
Assets	5,054,235	4,567,182
Other Services
Segment Reporting Information [Line Items]
Operating revenue	13,491	15,859	18,318
Less:
Production expenses	5,701	5,259	4,302
Administrative and general	1,306	2,632	2,777
Maintenance	2,771	2,052	1,757
Property taxes and other non-income taxes	47	317	926
Depreciation and amortization	121	253	646
Interest on long-term debt and other interest expense	0	521	329
Provision (benefit) for income taxes	1,371	1,569	2,213
Other	(587)	191	(121)
Net income	2,761	3,065	5,489
Capital expenditures	0	29	24,244
Assets	26,707	25,053
Unallocated Corporate
Segment Reporting Information [Line Items]
Operating revenue	0	0	0
Less:
Production expenses	0	0	0
Administrative and general	5,027	5,778	2,624
Maintenance	0	0	0
Property taxes and other non-income taxes	118	388	80
Depreciation and amortization	916	893	893
Interest on long-term debt and other interest expense	21,112	23,384	23,072
Provision (benefit) for income taxes	(8,944)	(9,733)	(7,550)
Other	(2,863)	(3,095)	(3,252)
Net income	(15,366)	(17,615)	(15,867)
Capital expenditures	0	0	$ 0
Assets	$ 68,624	$ 66,074

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2025
Audit Information [Abstract]
Auditor Name	Deloitte & Touche LLP
Auditor Location	San Jose, California
Auditor Firm ID	34

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
Cybersecurity Risk Management and Strategy Disclosure	Dec. 31, 2025
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	We have taken critical steps to ensure the security and protection of our computer systems and networks. Our processes for assessment, identification and management of material risks from cybersecurity threats include routine monitoring of vulnerabilities, evaluations of new service providers, written policies for incident identification and management, and regular testing and assessment of our cybersecurity posture. We have integrated cybersecurity risk management as part of our company-wide culture. The measures undertaken include, but are not limited to, monthly cybersecurity training for all employees and frequent communication to all employees on the importance of cybersecurity measures. We continue to advance our cybersecurity governance program and are evolving key practices to align with the National Institute of Standards and Technology (“NIST”) Cybersecurity Framework. These efforts include strengthening our risk assessment processes, control environment, and incident‑response capabilities. We have engaged third-party experts to assist us in monitoring and managing our cybersecurity process. Furthermore, we monitor cybersecurity threats at certain of our third-party vendors on a regular basis. As of the date of this report, we are not aware of any material risks from cybersecurity threats that have materially affected or are reasonably likely to materially affect the company, including our business strategy, results of operations, or financial condition. We have discussed cybersecurity risks that may affect the company in Item 1A, “Risk Factors,” under the headings, “The necessity for ongoing physical and technological security has resulted, and may continue to result, in increased operating costs,” “Water Utility Services rely on information technology and systems that are key to business operations. A system malfunction, security breach, cyber-attacks or other disruption that compromises our information and expose us to liability and adversely affect business operations. In addition, noncompliance could expose us to liability and adversely affect business operations,” and “We may not be able to maintain adequate insurance coverage at reasonable costs, or at all, to cover all losses incurred in our operations.”
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	We have taken critical steps to ensure the security and protection of our computer systems and networks. Our processes for assessment, identification and management of material risks from cybersecurity threats include routine monitoring of vulnerabilities, evaluations of new service providers, written policies for incident identification and management, and regular testing and assessment of our cybersecurity posture. We have integrated cybersecurity risk management as part of our company-wide culture. The measures undertaken include, but are not limited to, monthly cybersecurity training for all employees and frequent communication to all employees on the importance of cybersecurity measures. We continue to advance our cybersecurity governance program and are evolving key practices to align with the National Institute of Standards and Technology (“NIST”) Cybersecurity Framework. These efforts include strengthening our risk assessment processes, control environment, and incident‑response capabilities.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	On the basis of these meetings and discussions regarding such risks, the Chairman of the Audit Committee reports periodically to the full Board. The Vice President, Information Security Officer provides cybersecurity updates to the Audit Committee and other members of our senior management as appropriate at least quarterly. Our Vice President, Information Security Officer, and his team is responsible for leading enterprise-wide cybersecurity strategy, policy, standards, architecture, and processes, with the support of third-party experts. The Vice President, Information Security Officer has over 30 years of experience in information technology of which over 20 years is in cybersecurity, with industry experience in utilities, banking and e-commerce.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	The Vice President, Information Security Officer provides cybersecurity updates to the Audit Committee and other members of our senior management as appropriate at least quarterly. Our Vice President, Information Security Officer, and his team is responsible for leading enterprise-wide cybersecurity strategy, policy, standards, architecture, and processes, with the support of third-party experts.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	On the basis of these meetings and discussions regarding such risks, the Chairman of the Audit Committee reports periodically to the full Board. The Vice President, Information Security Officer provides cybersecurity updates to the Audit Committee and other members of our senior management as appropriate at least quarterly. Our Vice President, Information Security Officer, and his team is responsible for leading enterprise-wide cybersecurity strategy, policy, standards, architecture, and processes, with the support of third-party experts. The Vice President, Information Security Officer has over 30 years of experience in information technology of which over 20 years is in cybersecurity, with industry experience in utilities, banking and e-commerce.
Cybersecurity Risk Role of Management [Text Block]	We have implemented an internal risk assessment process that focuses on the principal risks that have been identified for us, including risks associated with our regulatory environment, business operations and continuity, compliance requirements, information technology and data storage and retrieval facilities, cyber risk, insurance coverage. The Audit Committee, pursuant to its charter, meets at least quarterly with senior leadership and other employees to discuss identified risks and the measures taken to control, manage and mitigate those risks, which include cyber and information security risk. On the basis of these meetings and discussions regarding such risks, the Chairman of the Audit Committee reports periodically to the full Board. The Vice President, Information Security Officer provides cybersecurity updates to the Audit Committee and other members of our senior management as appropriate at least quarterly. Our Vice President, Information Security Officer, and his team is responsible for leading enterprise-wide cybersecurity strategy, policy, standards, architecture, and processes, with the support of third-party experts. The Vice President, Information Security Officer has over 30 years of experience in information technology of which over 20 years is in cybersecurity, with industry experience in utilities, banking and e-commerce.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	The Vice President, Information Security Officer provides cybersecurity updates to the Audit Committee and other members of our senior management as appropriate at least quarterly. Our Vice President, Information Security Officer, and his team is responsible for leading enterprise-wide cybersecurity strategy, policy, standards, architecture, and processes, with the support of third-party experts. The Vice President, Information Security Officer has over 30 years of experience in information technology of which over 20 years is in cybersecurity, with industry experience in utilities, banking and e-commerce.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	The Vice President, Information Security Officer has over 30 years of experience in information technology of which over 20 years is in cybersecurity, with industry experience in utilities, banking and e-commerce.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	The Vice President, Information Security Officer provides cybersecurity updates to the Audit Committee and other members of our senior management as appropriate at least quarterly. Our Vice President, Information Security Officer, and his team is responsible for leading enterprise-wide cybersecurity strategy, policy, standards, architecture, and processes, with the support of third-party experts.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Organization and Operations	12 Months Ended
Organization and Operations	Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Operations	Organization and Operations The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of H2O America, its wholly owned subsidiaries, and one variable interest entity in which one H2O America subsidiary is the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. The accounting policies of H2O America’s subsidiaries comply with the applicable uniform system of accounts prescribed by the respective regulators and conform to generally accepted accounting principles for rate-regulated public utilities. H2O America is a holding company that conducts its business through the following wholly owned subsidiaries: San Jose Water Company (“SJWC”), H2O America TX Holdings, Inc., H2O America Land Company, H2O America NE LLC, and National Water Utility Service, LLC (“NWU”). H2O America TX Holdings, Inc. is a holding company for its wholly owned subsidiaries, SJWTX, Inc., doing business as The Texas Water Company (“TWC”), Texas Water Operation Services, LLC (“TWOS”) and Texas Water Resources, LLC (“TWR”). H2O America NE LLC is the holding company for Connecticut Water Service, Inc. (“CTWS”) whose wholly owned subsidiaries are The Connecticut Water Company (“CWC”), The Maine Water Company (“MWC”), New England Water Utility Services, Inc. (“NEWUS”), and Chester Realty, Inc. NWU is the contracting entity for shared services among the H2O America affiliates formed in October 2024. H2O America, through its wholly owned subsidiaries, primarily provides water utility and other related services in California, Connecticut, Maine and Texas. H2O America has business in property management and real estate investment activity conducted by H2O America Land Company and Chester Realty, Inc. TWC is a public utility in the business of providing water service in Bandera, Blanco, Comal, Hays, Kendall, Medina and Travis Counties in the growing region between San Antonio and Austin, Texas. TWC additionally provides wastewater service in Comal and Kendall counties. TWC also holds a 25% equity interest in Acequia Water Supply Corporation (“Acequia”). Acequia has been determined to be a variable interest entity within the scope of Accounting Standards Codification (“ASC”) Topic 810—“Consolidation” with TWC as the primary beneficiary. As a result, Acequia has been consolidated with TWC. TWOS was created for non-tariffed service operations and TWR was formed to hold wholesale water supply assets. Water sales are seasonal in nature and influenced by weather conditions. The timing of precipitation and climatic conditions can cause seasonal water consumption by customers to vary significantly. Revenue is generally higher in the warm, dry summer months when water usage and sales are greater and lower in the winter months when cooler temperatures and increased rainfall curtail water usage and sales.

Benefit Plans - Schedule of Amounts Recognized in Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	$ 80,967	$ 66,422
Noncurrent liabilities	(45,878)	(45,063)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	73,954	61,231
Current liabilities	(2,958)	(2,308)
Noncurrent liabilities	(40,686)	(38,020)
Liabilities, net	30,310	20,903
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	7,013	5,191
Current liabilities	(129)	(146)
Noncurrent liabilities	(5,697)	(6,900)
Liabilities, net	$ 1,187	$ (1,855)

- Definition

Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

+ References + Details

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (k)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (j)(1)
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (j)(3)
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (c)(ii)
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-7

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
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Reference 20: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-5

+ Details

Benefit Plans

12 Months Ended

Dec. 31, 2025

Retirement Benefits [Abstract]

Benefit Plans

Pension Plans

H2O America maintains noncontributory defined benefit pension plans for its eligible employees. SJWC employees hired before March 31, 2008 and CWC and MWC employees hired before January 1, 2009 are entitled to benefits under the pension plans based on the employee’s years of service and compensation. For SJWC employees hired on or after March 31, 2008, benefits are determined using a cash balance formula based upon compensation credits and interest credits for each employee. Effective January 1, 2023, TWC employees became eligible to participate under SJWC’s cash balance plan. Interest is credited based on the annual yield on 30-year Treasury bonds as of October for the preceding plan year with a minimum annual rate of 3.25% and a maximum annual rate of 6.00%. For the year ended December 31, 2025, the interest credits assumption was 4.25%. Certain employees hired before March 1, 2012, and covered by a plan merged into the CWC plan in 2013 are also entitled to benefits based on the employee’s years of service and compensation. CTWS employees hired on or after January 1, 2009 are entitled to an additional 3.0% of eligible compensation to their company sponsored savings plan. H2O America does not have multi-employer plans.

The pension plans are administered by their respective committees which oversee plan governance and are responsible for establishing investment objectives, policies, and guidelines to achieve the goals of income generation and long-term capital

preservation. H2O America engages third-party investment professionals to assist with, among other things, asset allocation strategy, investment policy advice, performance monitoring, and investment manager due diligence. Effective in 2025, the pension plan committees appointed a discretionary investment manager that qualifies as an “investment manager” under Section 3(38) of the employee retirement income security act of 1974. Under this arrangement, the investment manager has discretionary authority to make investment decisions and to select, appoint, monitor, and terminate underlying investment managers within the parameters established by the pension plans’ investment policies. The pension plan committees retain oversight responsibility and continue to monitor the performance of the investment manager, including reviews of investment results and compliance with the plans’ investment guidelines. Investment managers are not permitted to invest outside of the asset class or strategy authorized under those guidelines. The committees ensure that the plans establish a target mix that is expected to achieve its investment objectives by assuring a broad diversification of investment assets among investment types, while minimizing volatility of the target asset mix, unless market conditions make such a change appropriate to reduce risk. The pension plans require a minimum portion of plan assets to be allocated to fixed income securities and provide guidelines and restrictions on equity investments for the assets.

Plan assets are marked to market at each measurement date, resulting in unrealized actuarial gains or losses. Unrealized actuarial gains and losses on pension assets are amortized over the expected future working lifetime of participants for actuarial expense calculation purposes.

Generally, it is expected of the investment managers that the performance of the assets held in the pension plans, computed on a total annual rate of return basis, should meet or exceed specific performance standards over a three-to-five-year period and/or full market cycle. These standards include specific absolute and risk-adjusted performance standards over a three-to-five-year period and/or full market cycle. The expected long-term rate of return on the pension plan assets is between 6.50% and 6.75% for the year ended December 31, 2025.

H2O America calculates the market-related value of defined benefit pension plan assets, which is defined under FASB ASC Topic 715—“Compensation—Retirement Benefits,” as a balance used to calculate the expected return on plan assets, using fair value. The fair value is based on quoted prices in active markets for identical assets and significant observable inputs.

Certain senior management hired before March 31, 2008 for SJWC and January 1, 2009 for CWC are eligible to receive additional retirement benefits under the supplemental executive retirement plans and retirement contracts (collectively, “SERP”). SJWC’s senior management hired on or after March 31, 2008 are eligible to receive additional retirement benefits under SJWC’s Cash Balance Executive Supplemental Retirement Plan (“Cash Balance Executive Supplemental Retirement Plan”). Both of the plans are non-qualified plans in which only senior management and other designated members of management may participate. The annual cost of the plans has been included in the determination of the net periodic benefit cost shown below. The SERP and Cash Balance Executive Supplemental Retirement Plan had a projected benefit obligation of $43,644 and $40,328 as of December 31, 2025 and 2024, respectively, and net periodic pension cost of $3,212, $3,879 and $3,257 for 2025, 2024 and 2023, respectively. For the years ended December 31, 2025, 2024 and 2023, the amounts not recognized as a component of net periodic benefit cost was $(493), $169, and $314, respectively, recorded as other comprehensive income on the consolidated financial statements. SJWC’s non-qualified deferred compensation plans (“NQDCs”) are unfunded. By contrast, CWC’s non-qualified deferred compensation plans are funded, including SERP, through investments consisting primarily of life insurance contracts and assets are held in a Rabbi Trust. As of December 31, 2025 and 2024, total investments made to fund CWC’s SERP were $7,887 and $7,336, respectively, which is included in “Investments” in H2O America’s Consolidated Balance Sheets. The life insurance contracts are valued at cash surrender value of the policies as reported by the insurer. As of December 31, 2025 and 2024, the value of the life insurance contracts was $4,852 and $4,294, respectively.

The following tables summarize the fair values of the Rabbi Trust investment assets to fund CWC’s SERP by major categories as of December 31, 2025 and 2024:


			Fair Value Measurements at December 31, 2025
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Money market funds	$	354	354	—	—
Mutual funds	1,844		1,844	—	—
Fixed income	593		593	—	—
Total	$	2,791	2,791	—	—


			Fair Value Measurements at December 31, 2024
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Money market funds	$	28	28	—	—
Mutual funds	2,062		2,062	—	—
Fixed income	722		722	—	—
Total	$	2,812	2,812	—	—

Other Postretirement Benefits

In addition to providing pension and savings benefits, the company also provides health care and life insurance benefits for eligible retired employees under the respective employer-sponsored postretirement benefits other than pension plans. The benefits are paid by the company and not from plan assets due to limitations imposed by Internal Revenue Service.

Flexible Spending Plan

H2O America sponsors flexible spending account plans for its employees for the purpose of providing eligible employees with the opportunity to choose from among the fringe benefits available under the plans. The flexible spending plan is intended to qualify as a cafeteria plan under the provisions of the Internal Revenue Code Section 125. The flexible spending plan allows employees to save pre-tax income in a Health Care Spending Account (“HCSA”) and/or a Dependent Care Spending Account (“DCSA”) to help defray the cost of out-of-pocket medical and dependent care expenses. The annual maximum limit under the HCSA and DCSA plans is $3.3 and $5, respectively.

Savings Plans for Employees

H2O America also sponsors salary deferral plans which are defined contribution plans that allow employees to defer and contribute a portion of their earnings to the plan. Contributions, not to exceed set limits, are matched by the company. H2O America contributions were $4,928, $4,221 and $3,902 in 2025, 2024 and 2023, respectively. All of the company’s contributions are invested at the direction of the employees in funds offered under the plans.

Special Deferral Election Plans and Deferral Election Program

H2O America maintains a special deferral election plan and a deferred compensation plan and agreements for senior management and a deferral election program for non-employee directors allowing for the deferral of a portion of their earnings each year and to realize an investment return on those funds during the deferral period. Senior management and non-employee directors have to make an election on the deferral and distribution method of the deferrals before services are rendered. CWC’s deferred compensation plan allows the company to make discretionary contributions. Senior management and non-employee directors had deferred $8,767 and $8,216 under the plans as of December 31, 2025 and 2024, respectively. As of December 31, 2025 and 2024, $6,552 and $6,276, respectively, of the total amount deferred is related to CWC agreements.

Assumptions Utilized on Actuarial Calculations

Net periodic cost for the defined benefit plans and other postretirement benefits was calculated using the following assumptions:


	Pension Benefits			Other Postretirement Benefits
	2025	2024	2023	2025	2024	2023
	%	%	%	%	%	%
Discount rate	5.55 - 5.63	4.99 - 5.03	4.95 - 5.24	5.48 - 5.58	4.95 - 5.01	4.96 - 5.21
Expected return on plan assets	6.50, 6.75	6.25, 6.75	6.00, 6.75	4.20, 6.50	4.20, 6.25	4.20, 6.00
Rate of compensation increase	4.50, 5.00	4.50, 5.00	4.50, 5.00	N/A	N/A	N/A

The expected rate of return on plan assets was determined based on a review of historical returns, for the pension plans and for medium- to large-sized defined benefit pension funds with similar asset allocations. This review generated separate expected returns for each asset class. These expected future returns were then blended based on the pension plans’ target asset allocations.

Benefit obligations for the defined benefit plans and other postretirement benefits were calculated using the following assumptions as of December 31:


	Pension Benefits		Other Postretirement Benefits
	2025	2024	2025	2024
	%	%	%	%
Discount rate	5.35 - 5.54	5.55 - 5.63	5.11 - 5.43	5.48 - 5.58
Rate of compensation increase	4.50 - 5.00	4.50 - 5.00	N/A	N/A

H2O America utilized each plan’s projected benefit stream in conjunction with the FTSE Pension Discount Curve in determining the discount rate used in calculating the pension and other postretirement benefits liabilities at the measurement date.

H2O America has adopted MP-2021, Mortality Improvement Scales to determine mortality assumptions. The tables and scales reflect increasing life expectancies of participants in the United States. See also “Reconciliation of Funded Status” below.

For other postretirement benefits, the assumed healthcare cost trend rate for 2025 is 8.00%, grading down gradually to 4.50% by 2033.

Net Periodic Pension Costs

Net periodic costs for the defined benefit plans and other postretirement benefits for the years ended December 31 were as follows:


	Pension Benefits				Other Postretirement Benefits
	2025		2024	2023	2025		2024	2023
Components of net periodic benefit cost
Service cost	$	6,571	6,662	7,569	$	624	665	638
Interest cost	15,600		14,451	14,234	1,351		1,181	1,268
Expected return on assets	(19,777)		(17,852)	(15,440)	(1,179)		(1,068)	(860)

Amortization of prior service cost	15		15	15	—		—	—
Amortization of actuarial (gain) loss	(1,801)		(71)	2,210	(856)		(643)	(350)
Recognition of significant event	—		—	—	—		—	—
Net periodic benefit cost	$	608	3,205	8,588	$	(60)	135	696

Reconciliation of Funded Status

For the defined benefit plans and other postretirement benefits, the benefit obligation is the projected benefit obligation and the accumulated benefit obligation, respectively. The projected benefit obligations and the funded status of the defined benefit pension and other postretirement plans as of December 31 were as follows:


	Pension Benefits			Other Postretirement Benefits
	2025		2024	2025		2024
Change in benefit obligation
Benefit obligation at beginning of year	$	287,044	297,834	$	25,080	24,264
Service cost	6,571		6,662	624		665
Interest cost	15,600		14,451	1,351		1,181


Actuarial loss (gain)	4,860		(14,816)	(2,332)		(146)
Implicit rate subsidy	—		—	(109)		(336)
Plan participants contributions	—		—	149		183
Administrative expenses paid	(101)		(146)	—		—
Benefits paid and settlements	(20,832)		(16,941)	(1,042)		(731)
Benefit obligation at end of year	$	293,142	287,044	$	23,721	25,080
Change in plan assets
Fair value of assets at beginning of year	$	307,947	285,504	$	23,225	21,207
Actual return on plan assets	30,763		31,523	2,562		2,879

Employer contributions	5,675		8,007	7		7
Plan participants contributions	—		—	149		183
Administrative expenses paid	(101)		(146)	(48)		(71)
Benefits paid and settlements	(20,832)		(16,941)	(987)		(980)
Fair value of plan assets at end of year	323,452		307,947	24,908		23,225
Funded status at end of year	$	30,310	20,903	$	1,187	(1,855)

For the year ended December 31, 2025, the net actuarial loss on the benefit obligation was related primarily to a loss from changes in the discount rate of $4,219 and a $873 gain from pension data changes. For the year ended December 31, 2024, the net actuarial gain on the benefit obligation was related primarily to a gain from changes of discount rate of $21,129 and a $6,005 loss from pension data changes.

The amounts recognized on the balance sheet as of December 31 were as follows:


	Pension Benefits			Other Postretirement Benefits
	2025		2024	2025		2024
Noncurrent assets	$	73,954	61,231	$	7,013	5,191
Current liabilities	(2,958)		(2,308)	(129)		(146)
Noncurrent liabilities	(40,686)		(38,020)	(5,697)		(6,900)
	$	30,310	20,903	$	1,187	(1,855)

As of December 31, 2025 and 2024, the accumulated benefit obligation of the defined benefit pension plans was $269,908 and $263,607, respectively.

The following table provides selected information about plans with projected benefit obligation and accumulated benefit obligation in excess of plan assets as of December 31:


	2025		2024
Pension Benefits:
Plans with projected benefit obligation in excess of plan assets:
Projected benefit obligation	$	43,644	40,328
Fair value of plan assets	—		—
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	40,890		38,053
Fair value of plan assets	—		—
Other Postretirement Benefits:
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	15,874		16,891
Fair value of plan assets	10,047		9,844

H2O America recognizes regulatory assets and liabilities that represent actuarial losses and gains and prior service cost that have not yet been recognized as components of net periodic benefit cost for certain of its pension and other postretirement benefit plans, in accordance with ASC Topic 980. H2O America had no recorded regulatory assets as of December 31, 2025, and $3,177 as of December 31, 2024. Regulatory liabilities were $32,996 and $27,872 as of December 31, 2025 and 2024, respectively. As of December 31, 2024, the amount deferred in regulatory assets that has not yet been recognized as a component of net periodic benefit cost included a net loss of $3,150 and prior service cost of $27. As of December 31, 2025 and 2024, the amounts deferred in regulatory liabilities that have not yet been recognized as components of net periodic benefit cost include net gain of $32,996 and $27,872, respectively.

Plan Assets

Plan assets as of December 31 were as follows:


	Pension Benefits					Other Postretirement Benefits
	2025			2024		2025			2024
Fair value of assets at end of year:
Debt securities	$	169,758		116,987		$	8,656		5,368
	52		%	38	%	36		%	23	%
Equity securities	146,967			179,103		15,716			16,737
	45		%	58	%	63		%	72	%
Cash and equivalents	6,727			11,857		536			1,120
	2		%	4	%	2		%	5	%
Total	$	323,452		307,947		$	24,908		23,225

The following tables summarize the fair values of plan assets by major categories as of December 31, 2025 and 2024:


			Fair Value Measurements at December 31, 2025
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Cash and cash equivalents	$	7,263	7,263	—	—
Equity securities (a)	162,683		162,683	—	—
Fixed Income (b)	178,414		171,622	6,792	—
Total	$	348,360	341,568	6,792	—

___________________________________

(a)Actively managed portfolio of equity securities with the goal to exceed the benchmark performance.

(b)Actively managed portfolio of fixed income securities with the goal to exceed the benchmark performance.


			Fair Value Measurements at December 31, 2024
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Cash and cash equivalents	$	12,977	12,977	—	—
Equity securities	195,840		195,840	—	—
Fixed Income	122,355		46,549	75,806	—
Total	$	331,172	255,366	75,806	—

In 2026, H2O America expects to make required and discretionary cash contributions of up to $7,682 to the pension plans and other postretirement benefit plans.

Benefits expected to be paid in the next five years and in the aggregate for the five years thereafter are:


	Pension Plans		Other Postretirement Benefit Plans
2026	$	19,103	$	1,578
2027	20,009		1,659
2028	20,148		1,667
2029	20,855		1,675
2030	21,449		1,693
2031 - 2035	116,122		9,023

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (o)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (p)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (q)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480266/715-60-50-3

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480126/715-20-S99-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480794/715-70-50-1

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480482/715-20-55-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iv)(03)
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
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-Subparagraph (d)(i)
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/715/tableOfContent

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)(iii)
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-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Equity Plans (Tables)

12 Months Ended

Dec. 31, 2025

Share-Based Payment Arrangement [Abstract]

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan


	2025		2024	2023
Compensation costs charged to income:
ESPP	$	360	557	378
Restricted stock and deferred restricted stock	6,084		5,066	4,269
Total compensation costs charged to income	$	6,444	5,623	4,647
ESPP proceeds	$	2,131	2,188	2,141

Schedule of Restricted and Deferred Restricted Stock Awards


	Units	Weighted- Average Grant- Date Fair Value
Outstanding as of January 1, 2025	191,177	$	65.36
Granted	175,037	48.65
Issued	(70,611)	63.53
Forfeited	(17,038)	58.29
Outstanding as of December 31, 2025	278,565	$	52.32
Shares vested as of December 31, 2025	30,162	$	79.89

Schedule of Nonvested Restricted Stock Units Activity


	Units	Weighted- Average Grant- Date Fair Value
Nonvested as of January 1, 2025	159,156	$	64.30
Granted	175,037	48.65
Vested	(76,725)	68.03
Forfeited	(9,065)	58.29
Nonvested as of December 31, 2025	248,403	$	52.34

Summary of Significant Accounting Policies - Related-Party Transaction (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Related Party Transaction [Line Items]
Other, net	$ 3,545	$ 55	$ 8,882
Related Party
Related Party Transaction [Line Items]
Other, net	$ 4,400	$ 3,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147483326/850-10-50-3

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
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-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-13

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c)(2)(i))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(c)(2)(ii))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(2)(g)(3))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

+ Details

Lines of Credit (Tables)

12 Months Ended

Dec. 31, 2025

Debt Disclosure [Abstract]

Schedule of Line of Credit Facilities

A summary of the line of credit agreements as of December 31, 2025 and 2024 are as follows:


		2025				2024
	Maturity Date	Line Limit		Amounts Outstanding	Unused Portion	Amounts Outstanding
Syndicated credit agreement:	September 12, 2030
H2O America		$	50,000	11,000	39,000	3,000
SJWC		165,000		45,000	120,000	44,000
CTWS		—		—	—	30,000
CWC		80,000		13,000	67,000	—
MWC		25,000		—	25,000	—
SJWTX		30,000		16,000	14,000	—
Total syndicated credit agreement		350,000		85,000	265,000	77,000
SJWC credit agreement	June 11, 2026	10,000		—	10,000	—
CTWS credit agreement	August 2, 2028	10,000		1,834	8,166	2,124
CTWS credit agreement (1)	May 15, 2025	—		—	—	40,000
		$	370,000	86,834	283,166	119,124

(1) CTWS repaid the outstanding balance under this credit agreement and concurrently terminated this credit agreement.

Lines of Credit

12 Months Ended

Dec. 31, 2025

Debt Disclosure [Abstract]

Lines of Credit

H2O America and its subsidiaries have unsecured line of credit agreements where borrowings are used to refinance existing debt, for working capital, and for general corporate purposes. A summary of the line of credit agreements as of December 31, 2025 and 2024 are as follows:


		2025				2024
	Maturity Date	Line Limit		Amounts Outstanding	Unused Portion	Amounts Outstanding
Syndicated credit agreement:	September 12, 2030
H2O America		$	50,000	11,000	39,000	3,000
SJWC		165,000		45,000	120,000	44,000
CTWS		—		—	—	30,000
CWC		80,000		13,000	67,000	—
MWC		25,000		—	25,000	—
SJWTX		30,000		16,000	14,000	—
Total syndicated credit agreement		350,000		85,000	265,000	77,000
SJWC credit agreement	June 11, 2026	10,000		—	10,000	—
CTWS credit agreement	August 2, 2028	10,000		1,834	8,166	2,124
CTWS credit agreement (1)	May 15, 2025	—		—	—	40,000
		$	370,000	86,834	283,166	119,124

(1) CTWS repaid the outstanding balance under this credit agreement and concurrently terminated this credit agreement.

Total outstanding borrowings under the unsecured lines of credits as of December 31, 2025 and 2024 were $86,834 and $119,124, respectively. The weighted-average interest rate on short-term borrowings outstanding at December 31, 2025, was 4.75% compared to 6.08% at December 31, 2024. As of December 31, 2025, the unused portion of the lines of credit available for future borrowings was $283,166.

All of H2O America’s and subsidiaries’ lines of credit contain customary representations, warranties and events of default, as well as certain restrictive covenants customary for facilities of this type, including restrictions on indebtedness, liens, acquisitions and investments, restricted payments, asset sales, and fundamental changes. The lines of credit also include certain customary financial covenants such as a funded debt to capitalization ratio and a minimum interest coverage ratio. As of December 31, 2025, H2O America and its subsidiaries were in compliance with all covenants on the lines of credit.

Syndicated Credit Agreement

In August 2022, H2O America, SJWC, TWC, and CTWS have entered into a $300,000 credit agreement (the “Credit Agreement”) with JPMorgan Chase Bank, N.A., as Administrative Agent (“JP Morgan”), Wells Fargo Bank, National Association, as Documentation Agent, and a syndicate of banks with a term of five years. The Credit Agreement was subsequently amended to extend the maturity date from August 2027 to August 2028 and further amended to extend the maturity date to August 2029.

On September 12, 2025, H2O America and its subsidiaries, SJWC, SJWTX, CWC and MWC, entered into an Amended and Restated Credit Agreement to extend and increase the revolving credit facility with JPMorgan Chase Bank and Wells Fargo Securities, LLC. Pursuant to the amended agreement, the total commitment under the facility was increased from $300,000 to $350,000, and the maturity date was extended from August 2029 to September 12, 2030.

Under the terms of the Credit Agreement, each of H2O America, SJWC, SJWTX, CWC and MWC is a borrower with several and not joint liability. Each borrower has an initial borrowing entitlement, or sublimit, which can be periodically adjusted from time to time as set forth in the Credit Agreement. The initial sublimit of each borrower is as presented in the table above.

Borrowings under the Credit Agreement bear interest at either the Alternative Base Rate (as defined in the Credit Agreement and hereinafter referred to as “ABR”) or the Adjusted Term Secured Overnight Financing Rate (as defined in the Credit Agreement and hereinafter referred to as “SOFR”). ABR borrowings (which are borrowings bearing interest at a rate determined by reference to ABR) will bear interest at a rate per annum equal to ABR plus the applicable rate. SOFR borrowings (which are borrowings bearing interest at a rate determined by reference to SOFR) will bear interest at a rate per annum equal to SOFR plus the applicable rate. The applicable rate and pricing is variable depending on credit ratings of the borrower.

The Credit Agreement includes a financial covenant that requires each of the borrowers to maintain its funded debt to capitalization ratio at or below 70%.

As of December 31, 2025 and 2024, there were $85,000 and $77,000, respectively, in outstanding borrowings under the Credit Agreement.

CTWS Credit Agreements

Upon acquisition, CTWS held effective credit agreements with CoBank, ACB and Citizens Bank, N.A., (a former subsidiary of RBS Citizens, N.A. that was a party to the original credit agreement) that provided up to $40,000 and $75,000, respectively, in available borrowings. The credit agreement between CTWS and Citizens Bank, N.A. was amended in December 2019 which reduced available borrowings from $75,000 to $10,000. The credit agreement between CTWS and Citizens Bank, N.A., was further amended in August 2023 which extended the termination date from December 2023 to August 2, 2028. On July 11, 2025, CTWS repaid the outstanding balance of $25,000 under its credit agreement with CoBank, ACB and concurrently terminated the credit agreement.

As of December 31, 2025 and 2024, there were $1,834 and $2,124, respectively, in outstanding borrowings under the CTWS credit agreement with Citizens Bank, N.A.

SJWC Credit Agreement

On June 11, 2025, SJWC entered into a $10,000 credit agreement with JPMorgan Chase Bank, N.A., with a maturity date of June 11, 2026.

There were no outstanding borrowings under the credit agreement between SJWC and JPMorgan Chase Bank, N.A., as of December 31, 2025 and 2024.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Long-Term Debt - Narrative (Details) - USD ($) $ in Thousands			1 Months Ended
	Nov. 01, 2024	Oct. 01, 2024	Aug. 31, 2023	Dec. 31, 2025	Nov. 12, 2025	Oct. 28, 2025	Sep. 18, 2025	Jul. 10, 2025	Jun. 17, 2025	Dec. 31, 2024	Dec. 06, 2024	Jul. 31, 2024
Debt Instrument [Line Items]
Fair value of long-term debt				$ 1,716,589						$ 1,490,024
Long-term debt				1,901,201						1,719,824
KT Water Resource L. P.
Debt Instrument [Line Items]
Asset acquisition, period of post-closing production payment			29 years
SJWC \| Senior notes
Debt Instrument [Line Items]
Long-term debt				560,000						505,000
SJWC \| Senior notes \| 5.63% Senior Note, Series Q
Debt Instrument [Line Items]
Aggregate principal amount												$ 75,000
Rate												5.63%
SJWC \| Senior notes \| 5.83% Senior Note, Series R
Debt Instrument [Line Items]
Aggregate principal amount					$ 55,000
Rate					5.83%
CWC
Debt Instrument [Line Items]
Long-term debt				448,653						388,672
CWC \| Senior notes
Debt Instrument [Line Items]
Long-term debt				330,000						270,000
CWC \| Senior notes \| 5.78% Senior Note, Series 2024
Debt Instrument [Line Items]
Aggregate principal amount												$ 50,000
Rate												5.78%
CWC \| Senior notes \| 6.08% Senior Note, Series 2025
Debt Instrument [Line Items]
Aggregate principal amount						$ 60,000
Rate						6.08%
CWC \| Bank term loans
Debt Instrument [Line Items]
Long-term debt				96,295						96,295
TWR \| KT Water Resource L. P.
Debt Instrument [Line Items]
Asset acquisition, post-closing production payment			$ 29,000
TWC
Debt Instrument [Line Items]
Long-term debt				$ 149,000						109,000
TWC \| Senior notes
Debt Instrument [Line Items]
Rate				6.27%
Long-term debt				$ 15,000						15,000
TWC \| Bank term loans
Debt Instrument [Line Items]
Long-term debt				105,000						65,000
TWC \| Bank term loans \| 6.473% Promissory Note Due November 20, 2054
Debt Instrument [Line Items]
Rate											6.47%
Line Limit											$ 20,000
TWC \| Bank term loans \| 6.68% Promissory Note Due September 1, 2055
Debt Instrument [Line Items]
Rate							6.68%
Line Limit							$ 40,000
MWC
Debt Instrument [Line Items]
Long-term debt				101,336						72,763
MWC \| Bank term loans
Debt Instrument [Line Items]
Long-term debt				85,000						$ 60,000
MWC \| Bank term loans \| 6.473% Promissory Note Due November 20, 2054
Debt Instrument [Line Items]
Rate											6.47%
Line Limit											$ 15,000
MWC \| State revolving fund loans \| Series X Bond
Debt Instrument [Line Items]
Rate										1.00%
Long-term debt, gross		$ 3,330
Debt instrument, principal forgiveness		598
Long-term debt		$ 2,732
MWC \| State revolving fund loans \| Series Y Bond
Debt Instrument [Line Items]
Rate										1.00%
Long-term debt, gross	$ 3,596
Debt instrument, principal forgiveness	1,258
Long-term debt	$ 2,337
MWC \| Unsecured Debt \| 6.70% Promissory Note Due July 20, 2055
Debt Instrument [Line Items]
Rate								6.70%
Line Limit								$ 25,000	$ 25,000
Significant Observable Inputs (Level 2)
Debt Instrument [Line Items]
Fair value of long-term debt				1,715,635						$ 1,473,393
Significant Unobservable Inputs (Level 3)
Debt Instrument [Line Items]
Fair value of long-term debt				$ 954						$ 16,631

Summary of Significant Accounting Policies - Accounts Receivable (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2024 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reduction to allowance for credit losses	$ 7,822
Regulatory Asset Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reduction to allowance for credit losses	3,960
General and Administrative Expense
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reduction to allowance for credit losses	$ 3,862

Benefit Plans - Schedule of Fair Value of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 348,360	$ 331,172
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	341,568	255,366
Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,792	75,806
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Executive Supplemental Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,791	2,812
Executive Supplemental Retirement Plan \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,791	2,812
Executive Supplemental Retirement Plan \| Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Executive Supplemental Retirement Plan \| Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Executive Supplemental Retirement Plan \| Money market funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	354	28
Executive Supplemental Retirement Plan \| Money market funds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	354	28
Executive Supplemental Retirement Plan \| Money market funds \| Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Executive Supplemental Retirement Plan \| Money market funds \| Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Executive Supplemental Retirement Plan \| Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,844	2,062
Executive Supplemental Retirement Plan \| Mutual funds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,844	2,062
Executive Supplemental Retirement Plan \| Mutual funds \| Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Executive Supplemental Retirement Plan \| Mutual funds \| Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Executive Supplemental Retirement Plan \| Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	593	722
Executive Supplemental Retirement Plan \| Fixed income \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	593	722
Executive Supplemental Retirement Plan \| Fixed income \| Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Executive Supplemental Retirement Plan \| Fixed income \| Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

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+ Details

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Current assets:
Allowance for uncollectible accounts	$ 722	$ 1,172
Capitalization:
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	70,000,000	70,000,000
Common stock, shares issued (in shares)	36,118,242	33,629,169
Common stock, shares outstanding (in shares)	36,118,242	33,629,169

VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Allowance for doubtful accounts:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of period	$ 1,172	$ 6,551	$ 5,753
(Credited) charged to expense	3,636	(1,338)	3,594
(Credited) charged to regulatory asset	0	(3,960)	1,628
Accounts written off	(5,179)	(3,874)	(5,479)
Recoveries of accounts written off	1,093	3,793	1,055
Balance, end of period	722	1,172	6,551
Reserve for litigation and claims:
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, beginning of period	615	1,888	1,768
(Credited) charged to expense	97	206	971
Accounts written off	114	(39)	(166)
Payments	(411)	(1,440)	(685)
Balance, end of period	$ 415	$ 615	$ 1,888

Equity Plans - Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs charged to income:	$ 6,444	$ 5,623	$ 4,647
Restricted stock and deferred restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs charged to income:	6,084	5,066	4,269
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs charged to income:	360	557	378
ESPP proceeds	$ 2,131	$ 2,188	$ 2,141

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Income Taxes - Schedule of Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Current:
Federal	$ 5,276	$ (1,828)	$ 10,185
State	1,896	443	4,281
Deferred:
Federal	5,360	11,063	(8,871)
State	(177)	(708)	361
Income tax expense	$ 12,355	$ 8,970	$ 5,956

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 220
-SubTopic 40
-Name Accounting Standards Codification
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-Subparagraph (ee)
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-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
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-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.7)
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-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Section 45
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-Topic 235
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+ Details

Benefit Plans - Schedule of Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 348,360	$ 331,172
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	341,568	255,366
Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,792	75,806
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	162,683	195,840
Equity securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	162,683	195,840
Equity securities \| Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity securities \| Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,263	12,977
Cash and equivalents \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,263	12,977
Cash and equivalents \| Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and equivalents \| Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	178,414	122,355
Fixed income \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	171,622	46,549
Fixed income \| Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,792	75,806
Fixed income \| Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	323,452	307,947	$ 285,504
Pension Benefits \| Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 169,758	$ 116,987
Actual plan asset allocations as a percent of total plan assets	52.00%	38.00%
Pension Benefits \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 146,967	$ 179,103
Actual plan asset allocations as a percent of total plan assets	45.00%	58.00%
Pension Benefits \| Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 6,727	$ 11,857
Actual plan asset allocations as a percent of total plan assets	2.00%	4.00%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 24,908	$ 23,225	$ 21,207
Other Postretirement Benefits \| Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 8,656	$ 5,368
Actual plan asset allocations as a percent of total plan assets	36.00%	23.00%
Other Postretirement Benefits \| Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 15,716	$ 16,737
Actual plan asset allocations as a percent of total plan assets	63.00%	72.00%
Other Postretirement Benefits \| Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 536	$ 1,120
Actual plan asset allocations as a percent of total plan assets	2.00%	5.00%

Summary of Significant Accounting Policies - Impairments of Long-Lived Assets and Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Impairment of long-lived asset	$ 0	$ 0
Goodwill, impairment loss	$ 0	$ 0	$ 0

- Definition

Amount of impairment loss from asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

+ References + Details

Organization and Operations (Details)	12 Months Ended
Organization and Operations (Details)	Dec. 31, 2025 entity subsidiary
Public Utilities, General Disclosures [Line Items]
Number of variable interest entities \| entity	1
SJWC
Public Utilities, General Disclosures [Line Items]
Number of subsidiaries that are primary beneficiaries \| subsidiary	1
Variable Interest Entity, Not Primary Beneficiary
Public Utilities, General Disclosures [Line Items]
Ownership percentage in acequia water supply corporation	25.00%

Summary of Significant Accounting Policies - Earnings per Share (Details) - shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive restricted common stock units excluded from computation of earnings per share (in shares)	40,452	8,075	14,193

Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2025

Retirement Benefits [Abstract]

Schedule of Allocation of Plan Assets

The following tables summarize the fair values of the Rabbi Trust investment assets to fund CWC’s SERP by major categories as of December 31, 2025 and 2024:


			Fair Value Measurements at December 31, 2025
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Money market funds	$	354	354	—	—
Mutual funds	1,844		1,844	—	—
Fixed income	593		593	—	—
Total	$	2,791	2,791	—	—


			Fair Value Measurements at December 31, 2024
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Money market funds	$	28	28	—	—
Mutual funds	2,062		2,062	—	—
Fixed income	722		722	—	—
Total	$	2,812	2,812	—	—

Plan assets as of December 31 were as follows:


	Pension Benefits					Other Postretirement Benefits
	2025			2024		2025			2024
Fair value of assets at end of year:
Debt securities	$	169,758		116,987		$	8,656		5,368
	52		%	38	%	36		%	23	%
Equity securities	146,967			179,103		15,716			16,737
	45		%	58	%	63		%	72	%
Cash and equivalents	6,727			11,857		536			1,120
	2		%	4	%	2		%	5	%
Total	$	323,452		307,947		$	24,908		23,225

The following tables summarize the fair values of plan assets by major categories as of December 31, 2025 and 2024:


			Fair Value Measurements at December 31, 2025
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Cash and cash equivalents	$	7,263	7,263	—	—
Equity securities (a)	162,683		162,683	—	—
Fixed Income (b)	178,414		171,622	6,792	—
Total	$	348,360	341,568	6,792	—

___________________________________

(a)Actively managed portfolio of equity securities with the goal to exceed the benchmark performance.

(b)Actively managed portfolio of fixed income securities with the goal to exceed the benchmark performance.


			Fair Value Measurements at December 31, 2024
Asset Category	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)	Significant Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)
Cash and cash equivalents	$	12,977	12,977	—	—
Equity securities	195,840		195,840	—	—
Fixed Income	122,355		46,549	75,806	—
Total	$	331,172	255,366	75,806	—

Schedule of Assumptions Used

Net periodic cost for the defined benefit plans and other postretirement benefits was calculated using the following assumptions:


	Pension Benefits			Other Postretirement Benefits
	2025	2024	2023	2025	2024	2023
	%	%	%	%	%	%
Discount rate	5.55 - 5.63	4.99 - 5.03	4.95 - 5.24	5.48 - 5.58	4.95 - 5.01	4.96 - 5.21
Expected return on plan assets	6.50, 6.75	6.25, 6.75	6.00, 6.75	4.20, 6.50	4.20, 6.25	4.20, 6.00
Rate of compensation increase	4.50, 5.00	4.50, 5.00	4.50, 5.00	N/A	N/A	N/A

Benefit obligations for the defined benefit plans and other postretirement benefits were calculated using the following assumptions as of December 31:


	Pension Benefits		Other Postretirement Benefits
	2025	2024	2025	2024
	%	%	%	%
Discount rate	5.35 - 5.54	5.55 - 5.63	5.11 - 5.43	5.48 - 5.58
Rate of compensation increase	4.50 - 5.00	4.50 - 5.00	N/A	N/A

Schedule of Net Benefit Costs

Net periodic costs for the defined benefit plans and other postretirement benefits for the years ended December 31 were as follows:


	Pension Benefits				Other Postretirement Benefits
	2025		2024	2023	2025		2024	2023
Components of net periodic benefit cost
Service cost	$	6,571	6,662	7,569	$	624	665	638
Interest cost	15,600		14,451	14,234	1,351		1,181	1,268
Expected return on assets	(19,777)		(17,852)	(15,440)	(1,179)		(1,068)	(860)

Amortization of prior service cost	15		15	15	—		—	—
Amortization of actuarial (gain) loss	(1,801)		(71)	2,210	(856)		(643)	(350)
Recognition of significant event	—		—	—	—		—	—
Net periodic benefit cost	$	608	3,205	8,588	$	(60)	135	696

Schedule of Net Funded Status

The projected benefit obligations and the funded status of the defined benefit pension and other postretirement plans as of December 31 were as follows:


	Pension Benefits			Other Postretirement Benefits
	2025		2024	2025		2024
Change in benefit obligation
Benefit obligation at beginning of year	$	287,044	297,834	$	25,080	24,264
Service cost	6,571		6,662	624		665
Interest cost	15,600		14,451	1,351		1,181


Actuarial loss (gain)	4,860		(14,816)	(2,332)		(146)
Implicit rate subsidy	—		—	(109)		(336)
Plan participants contributions	—		—	149		183
Administrative expenses paid	(101)		(146)	—		—
Benefits paid and settlements	(20,832)		(16,941)	(1,042)		(731)
Benefit obligation at end of year	$	293,142	287,044	$	23,721	25,080
Change in plan assets
Fair value of assets at beginning of year	$	307,947	285,504	$	23,225	21,207
Actual return on plan assets	30,763		31,523	2,562		2,879

Employer contributions	5,675		8,007	7		7
Plan participants contributions	—		—	149		183
Administrative expenses paid	(101)		(146)	(48)		(71)
Benefits paid and settlements	(20,832)		(16,941)	(987)		(980)
Fair value of plan assets at end of year	323,452		307,947	24,908		23,225
Funded status at end of year	$	30,310	20,903	$	1,187	(1,855)

Schedule of Amounts Recognized in Balance Sheet

The amounts recognized on the balance sheet as of December 31 were as follows:


	Pension Benefits			Other Postretirement Benefits
	2025		2024	2025		2024
Noncurrent assets	$	73,954	61,231	$	7,013	5,191
Current liabilities	(2,958)		(2,308)	(129)		(146)
Noncurrent liabilities	(40,686)		(38,020)	(5,697)		(6,900)
	$	30,310	20,903	$	1,187	(1,855)

Schedule of Accumulated and Projected Benefit Obligations

The following table provides selected information about plans with projected benefit obligation and accumulated benefit obligation in excess of plan assets as of December 31:


	2025		2024
Pension Benefits:
Plans with projected benefit obligation in excess of plan assets:
Projected benefit obligation	$	43,644	40,328
Fair value of plan assets	—		—
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	40,890		38,053
Fair value of plan assets	—		—
Other Postretirement Benefits:
Plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	15,874		16,891
Fair value of plan assets	10,047		9,844

Schedule of Expected Benefit Payments

Benefits expected to be paid in the next five years and in the aggregate for the five years thereafter are:


	Pension Plans		Other Postretirement Benefit Plans
2026	$	19,103	$	1,578
2027	20,009		1,659
2028	20,148		1,667
2029	20,855		1,675
2030	21,449		1,693
2031 - 2035	116,122		9,023

FINANCIAL STATEMENT SCHEDULE - Condensed Balance Sheets (Details) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 20,686	$ 11,114
Other current assets	8,086	8,593
Total current assets	190,593	190,714
Other assets
Other	35,890	28,893
Total other assets	1,023,426	977,768
Total assets	5,149,566	4,658,309
Stockholders’ equity:
Common stock, $0.001 par value; authorized 70,000,000 shares in 2025 and 2024; issued and outstanding 36,118,242 shares in 2025 and 33,629,169 shares in 2024	36	34
Additional paid-in capital	958,188	827,796
Retained earnings	581,080	537,184
Accumulated other comprehensive income	1,467	1,960
Total stockholders’ equity	1,540,771	1,366,974	$ 1,233,397	$ 1,110,868
Long-term debt, less current portion	1,866,819	1,706,904
Total capitalization	3,407,590	3,073,878
Current liabilities:
Line of credit	86,834	119,124
Accounts payable	75,427	56,256
Accrued interest	18,241	17,476
Other current liabilities	20,942	23,236
Total current liabilities	273,378	261,173
Deferred income taxes	307,893	276,043
Other noncurrent liabilities	23,920	22,298
Total capitalization and liabilities	$ 5,149,566	$ 4,658,309
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	70,000,000	70,000,000
Common stock, shares issued (in shares)	36,118,242	33,629,169
Common stock, shares outstanding (in shares)	36,118,242	33,629,169
H2O America
Assets
Investments in subsidiaries	$ 2,037,519	$ 1,877,922
Current assets:
Cash and cash equivalents	175	1,306
Intercompany receivables	6,680	1,473
Intercompany notes receivable	102,780	74,119
Other current assets	4,372	1,177
Total current assets	114,007	78,075
Other assets
Other	287	222
Total other assets	287	222
Total assets	2,151,813	1,956,219
Stockholders’ equity:
Common stock, $0.001 par value; authorized 70,000,000 shares in 2025 and 2024; issued and outstanding 36,118,242 shares in 2025 and 33,629,169 shares in 2024	36	34
Additional paid-in capital	958,188	827,796
Retained earnings	581,080	537,184
Accumulated other comprehensive income	1,467	1,960
Total stockholders’ equity	1,540,771	1,366,974
Long-term debt, less current portion	557,832	557,430
Total capitalization	2,098,603	1,924,404
Current liabilities:
Line of credit	11,000	3,000
Intercompany payables	0	2,210
Intercompany notes payable	966	0
Accounts payable	3,274	1,588
Accrued interest	3,258	3,224
Income tax payable	31,661	16,871
Other current liabilities	408	765
Total current liabilities	50,567	27,658
Deferred income taxes	815	2,488
Other noncurrent liabilities	1,828	1,669
Total capitalization and liabilities	$ 2,151,813	$ 1,956,219

Insider Trading Policies and Procedures	12 Months Ended
Insider Trading Policies and Procedures	Dec. 31, 2025
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Benefit Plans - Schedule of Reconciliation of Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Change in plan assets
Fair value of assets at beginning of year	$ 331,172
Fair value of plan assets at end of year	348,360	$ 331,172
Pension Benefits
Change in benefit obligation
Benefit obligation at beginning of year	287,044	297,834
Service cost	6,571	6,662	$ 7,569
Interest cost	15,600	14,451	14,234
Actuarial loss (gain)	4,860	(14,816)
Implicit rate subsidy	0	0
Plan participants contributions	0	0
Administrative expenses paid	(101)	(146)
Benefits paid and settlements	(20,832)	(16,941)
Benefit obligation at end of year	293,142	287,044	297,834
Change in plan assets
Fair value of assets at beginning of year	307,947	285,504
Actual return on plan assets	30,763	31,523
Employer contributions	5,675	8,007
Plan participants contributions	0	0
Administrative expenses paid	(101)	(146)
Benefits paid and settlements	(20,832)	(16,941)
Fair value of plan assets at end of year	323,452	307,947	285,504
Funded status at end of year	30,310	20,903
Other Postretirement Benefits
Change in benefit obligation
Benefit obligation at beginning of year	25,080	24,264
Service cost	624	665	638
Interest cost	1,351	1,181	1,268
Actuarial loss (gain)	(2,332)	(146)
Implicit rate subsidy	(109)	(336)
Plan participants contributions	149	183
Administrative expenses paid	0	0
Benefits paid and settlements	(1,042)	(731)
Benefit obligation at end of year	23,721	25,080	24,264
Change in plan assets
Fair value of assets at beginning of year	23,225	21,207
Actual return on plan assets	2,562	2,879
Employer contributions	7	7
Plan participants contributions	149	183
Administrative expenses paid	(48)	(71)
Benefits paid and settlements	(987)	(980)
Fair value of plan assets at end of year	24,908	23,225	$ 21,207
Funded status at end of year	$ 1,187	$ (1,855)

Benefit Plans - Schedule of Benefits Expected to be Paid in Next Five Years (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Estimated required and discretionary employer cash contributions	$ 7,682
Pension Benefits
Expected Future Benefit Payments [Abstract]
2026	19,103
2027	20,009
2028	20,148
2029	20,855
2030	21,449
2031 - 2035	116,122
Other Postretirement Benefits
Expected Future Benefit Payments [Abstract]
2026	1,578
2027	1,659
2028	1,667
2029	1,675
2030	1,693
2031 - 2035	$ 9,023

Income Taxes - Schedule of Federal Statutory Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Tax Disclosure [Abstract]
Income before income taxes	$ 114,933	$ 102,937	$ 90,943
Amount
Income tax at federal statutory rate	24,136	21,617	19,098
Increase (decrease) in taxes attributable to:
State and local income taxes, net of federal income tax effect	1,326	6,488	6,001
Tax credits	(208)	0	0
Nontaxable or nondeductible items	543	0	0
Changes in unrecognized tax benefits	331	(1,053)	(4,330)
Property flow-through	0	(14,793)	(9,045)
Pension flow-through	0	(530)	(597)
Stock-based compensation	0	192	(491)
Flow-through	(11,933)	0	0
Reversal of excess deferred taxes recognized in regulatory liability	(1,517)	(3,227)	(3,625)
Other items	(323)	276	(1,055)
Income tax expense	$ 12,355	$ 8,970	$ 5,956
Percent
Income tax at federal statutory rate	21.00%
Increase (decrease) in taxes attributable to:
State and local income taxes, net of federal income tax effect	1.20%
Tax credits	(0.20%)
Nontaxable or nondeductible items	0.50%
Changes in unrecognized tax benefits	0.30%
Property flow-through	0.00%
Pension flow-through	0.00%
Stock-based compensation	0.00%
Flow-through	(10.40%)
Reversal of excess deferred taxes recognized in regulatory liability	(1.30%)
Other items	(0.30%)
Effective income tax rate	10.80%

FINANCIAL STATEMENT SCHEDULE

12 Months Ended

Dec. 31, 2025

Condensed Financial Information Disclosure [Abstract]

FINANCIAL STATEMENT SCHEDULE

Schedule I

H2O America (Parent Only)

CONDENSED BALANCE SHEETS

(in thousands, except share and per share data)


	December 31,
	2025		2024
Assets

Investments in subsidiaries	$	2,037,519	1,877,922

Current assets:
Cash and cash equivalents	175		1,306
Intercompany receivables	6,680		1,473

Intercompany notes receivable	102,780		74,119
Other current assets	4,372		1,177
Total current assets	114,007		78,075
Other assets


Other	287		222
Total other assets	287		222
Total assets	$	2,151,813	1,956,219

Capitalization and Liabilities
Capitalization:
Stockholders’ equity:
Common stock, $0.001 par value; authorized 70,000,000 shares in 2025 and 2024; issued and outstanding 36,118,242 shares in 2025 and 33,629,169 shares in 2024	$	36	34
Additional paid-in capital	958,188		827,796
Retained earnings	581,080		537,184
Accumulated other comprehensive income	1,467		1,960
Total stockholders’ equity	1,540,771		1,366,974
Long-term debt, less current portion	557,832		557,430
Total capitalization	2,098,603		1,924,404
Current liabilities:
Line of credit	11,000		3,000
Intercompany payables	—		2,210
Intercompany notes payable	966		—
Accounts payable	3,274		1,588
Accrued interest	3,258		3,224
Income tax payable	31,661		16,871
Other current liabilities	408		765
Total current liabilities	50,567		27,658
Deferred income taxes	815		2,488

Other noncurrent liabilities	1,828		1,669
Total capitalization and liabilities	$	2,151,813	1,956,219

See Accompanying Notes to Schedule I

FINANCIAL STATEMENT SCHEDULE

Schedule I

H2O America (Parent Only)

CONDENSED STATEMENTS OF COMPREHENSIVE INCOME

Years ended December 31 (in thousands)


	2025		2024	2023
Operating revenue	$	—	—	—
Operating expense:
Administrative and general	4,664		5,568	2,239
Property taxes and other non-income taxes	118		388	80


Total operating expense	4,782		5,956	2,319
Operating loss	(4,782)		(5,956)	(2,319)
Other (expense) income:
Interest on long-term debt and other interest expense	(17,862)		(18,022)	(17,692)


Interest income on intercompany notes receivable	6,292		6,756	3,862
Other, net	(4,613)		(3,456)	1,034
Loss before income taxes and equity earnings from subsidiaries	(20,965)		(20,678)	(15,115)
Income tax benefit	(6,015)		(5,727)	(4,294)
Equity earnings from subsidiaries, net of taxes	117,528		108,918	95,808
H2O America net income	102,578		93,967	84,987
Other comprehensive income, net	(493)		169	314
H2O America comprehensive income	$	102,085	94,136	85,301

See Accompanying Notes to Schedule I

FINANCIAL STATEMENT SCHEDULE

Schedule I

H2O America (Parent Only)

CONDENSED STATEMENTS OF CASH FLOWS

Years ended December 31 (in thousands)


	2025		2024	2023
Operating activities:
Net income	$	102,578	93,967	84,987
Adjustments to reconcile net income to net cash used in operating activities:
Earnings from investment in subsidiaries	(117,666)		(108,918)	(95,808)

Deferred income taxes	(1,644)		(618)	718
Stock-based compensation	842		687	696


Changes in operating assets and liabilities, net of acquired assets and liabilities:
Accounts payable and other current liabilities	1,329		1,724	281
Intercompany receivables	(18,387)		(652)	(6,018)
Tax payable and other accrued taxes	14,761		452	1,550
Accrued interest	34		(31)	47
Return on capital from investments in subsidiaries	59,400		90,600	50,550
Proceeds from litigation settlement, net	—		—	—

Other changes, net	(2,677)		532	607
Net cash provided by operating activities	38,570		77,743	37,610
Investing activities:
Proceeds to subsidiaries for notes receivable	(237,246)		(173,374)	(148,392)
Repayments from subsidiaries for notes receivable	208,585		169,001	91,740
Investments in subsidiaries	(84,037)		(97,000)	(25,500)


Net cash used in investing activities	(112,698)		(101,373)	(82,152)
Financing activities:
Borrowings from subsidiaries for notes payable	1,121		27,098	700
Repayments to subsidiaries for notes payable	(155)		(28,824)	(3,140)
Borrowings from lines of credit	133,000		35,000	10,000
Repayments of lines of credit	(125,000)		(42,000)	—


Issuance of common stock, net of issuance costs	122,808		85,008	80,659
Proceeds from litigation settlement, net	—		—	—
Debt issuance costs	(132)		(82)	(46)
Dividends paid	(58,645)		(52,132)	(47,905)

Net cash provided (used in) by financing activities	72,997		24,068	40,268
Net change in cash and cash equivalents	(1,131)		438	(4,274)
Cash and cash equivalents, beginning of year	1,306		868	5,142
Cash and cash equivalents, end of year	$	175	1,306	868
Cash paid (refunded) during the year for:
Interest	$	17,713	17,919	17,465
Income taxes	$	(9,676)	—	(4,870)
Supplemental disclosure of non-cash activities:
Share-based compensation from investment in subsidiaries	$	6,707	5,879	3,778

See Accompanying Notes to Schedule I

FINANCIAL STATEMENT SCHEDULE

Schedule I

H2O America (Parent Only)

NOTES TO CONDENSED FINANCIAL STATEMENTS

Years ended December 31, 2025, 2024 and 2023

(Dollars in thousands, except share and per share data)

Financing Activities

See Note 5, “Lines of Credit” and Note 6, “Long-term Debt” for additional information on H2O America’s revolving credit facility and outstanding debt.

The following is a table of the H2O America’s schedule of principal payments on long-term debt:


Year
2026	$	—
2027	—
2028	—
2029	310,000
2030	50,000
Thereafter	200,000

Restrictions on Dividends and Other Distributions

H2O America is a legal entity separate and distinct from its various subsidiaries. As a holding company with no significant operations of its own, H2O America’s principal sources of funds are dividends or other distributions from its operating subsidiaries, borrowings and the issuance of equity. The rights of H2O America and, consequently, its creditors and shareholders, to participate in any distribution of assets of any of its subsidiaries are subject to certain prior claims of creditors of such subsidiary.

The abilities of certain of H2O America’s subsidiaries to transfer funds to H2O America in the form of cash dividends, loans or advances are subject to certain contractual and regulatory restrictions. H2O America and its subsidiaries are subject to debt covenants that could limit their respective abilities to pay dividends. For a discussion on these covenants, see Note 6, “Long-term Debt” to H2O America and Subsidiaries Notes to Consolidated Financial Statements. In addition, CTWS and its regulated subsidiaries are prohibited from paying dividends if not in compliance with minimum equity requirements under commitments made by H2O America as part of the approval granted by the PURA and the Maine Public Utilities Commission in connection with the acquisition of CTWS.

As of December 31, 2025, the restricted net assets of H2O America’s subsidiaries were approximately $501,724 or 33% of consolidated net assets of H2O America.

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Unrealized gain (loss) on investment, tax expense (benefit)	$ 0	$ (163)	$ 166
Adjustment to pension benefit plans, tax benefit	$ 0	$ 0	$ 80

FINANCIAL STATEMENT SCHEDULE - Schedule of Principal Payments on Long-Term Debt (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Condensed Financial Statements, Captions [Line Items]
2026	$ 23,950
2027	3,207
2028	44,699
2029	325,624
2030	53,201
Thereafter	1,450,520
H2O America
Condensed Financial Statements, Captions [Line Items]
2026	0
2027	0
2028	0
2029	310,000
2030	50,000
Thereafter	$ 200,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Subsection 04
-Paragraph a
-Publisher SEC

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
-Section 5
-Subsection 04
-Paragraph c
-Subparagraph Schedule I
-Publisher SEC

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
-Section 7
-Subsection 05
-Paragraph c
-Subparagraph Schedule II
-Publisher SEC

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
-Section 9
-Subsection 06
-Publisher SEC

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3

Reference 8: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481231/810-10-45-11

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 7
-Subparagraph (SAB Topic 1.B.2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480922/205-10-S99-7

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481003/205-10-S50-2

+ Details

Capitalization (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended	14 Months Ended
	Dec. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Oct. 29, 2024
Subsidiary, Sale of Stock [Line Items]
Common stock, shares authorized (in shares)	70,000,000	70,000,000	70,000,000
Common stock, par value (in usd per share)	$ 0.001	$ 0.001	$ 0.001
Common stock, shares issued (in shares)	36,118,242	36,118,242	33,629,169
Common stock, shares outstanding (in shares)	36,118,242	36,118,242	33,629,169
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000	1,000,000
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001	$ 0.001
Preferred stock, shares issued (in shares)	0	0	0
Preferred stock, shares outstanding (in shares)	0	0	0
At The Market Offering
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in usd per share)				$ 0.001
Aggregate gross sales price (up to)				$ 200,000
Shares issued in offering (in shares)	2,387,846	2,763,359
Weighted average price per share (in usd per share)	$ 51.90	$ 52.39
Net proceeds from stock offering	$ 122,806	$ 142,975
Total equity distribution	$ 55,239	$ 55,239

Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2025

Regulated Operations [Abstract]

Schedule of Regulatory Assets, Net

Regulatory assets and liabilities are comprised of the following as of December 31:


	2025		2024
Regulatory assets:
Income tax temporary differences (a) (q)	$	204,384	180,103
MWRAM (b)	8,553		9,985
Business combinations debt premium (c) (q)	9,772		12,313
Employee benefit costs (d) (q)	5,823		6,370
Catastrophic event memorandum accounts (“CEMA”) (p)	127		986
Revenue adjustment mechanisms (e) (q)	7,931		5,024
Customer Assistance Program (“CAP”) balancing account (f)	3,696		6,599
Water supply costs (i)	847		—
Unrecognized pensions and other postretirement benefits (g) (q)	—		3,177
2022 general rate case interim memorandum account (h)	—		3,392
Other (j)	13,729		14,278
Total regulatory assets	254,862		242,227
Less: current regulatory asset (k)	8,315		18,172
Total regulatory assets, less current portion	$	246,547	224,055
Regulatory liabilities:
Cost of removal (l)	$	394,391	364,398
Future income tax benefits due to customers (m)	82,285		84,128
Unrecognized pensions and other postretirement benefits (g)	32,996		27,872
PFAS legal settlement proceeds (r)	24,682		—
Employee benefit costs (d)	8,771		1,137
Revenue adjustment mechanisms (e)	—		1,122
Water supply costs (i)	—		3,386
Other (n)	3,672		2,798
Total regulatory liabilities	546,797		484,841
Less: current regulatory liabilities (o)	—		1,122
Total regulatory liabilities, less current portion	$	546,797	483,719

___________________________________

(b)MWRAM is described in the previous section.

(c)Consists of debt fair value adjustments recognized through purchase accounting for the completed merger with CTWS in 2019.

(d)Includes deferrals of pension and other postretirement benefit expense, cost of accrued benefits for vacation, and group health insurance.

(e)Consists of WRA and WCMA, which are described in the previous section.

(f)Represents costs associated with SJWC’s CAP.

(l)Represents amounts collected in rates from customers for estimated costs to retire assets at the end of their expected useful lives before the costs are incurred.

(n)Other includes other balancing and memorandum accounts and regulatory mechanisms, and other regulatory mechanisms.

(o)Primarily relates to the current portion of WRA.

(q)Generally not earning a return either by interest on the regulatory asset or as a component of rate base at the allowed rate of return.

Long-Term Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Total debt	$ 1,901,201	$ 1,719,824
Unamortized debt premium and discount, net	(1,644)	(56)
Unamortized debt issuance costs	(9,234)	(9,216)
Current portion	(23,504)	(3,648)
Total long-term debt, less current portion	1,866,819	1,706,904
H2O America
Debt Instrument [Line Items]
Total long-term debt, less current portion	557,832	557,430
H2O America \| Senior notes
Debt Instrument [Line Items]
Total debt	$ 560,000	560,000
H2O America \| Senior notes \| Minimum
Debt Instrument [Line Items]
Rate	2.47%
H2O America \| Senior notes \| Maximum
Debt Instrument [Line Items]
Rate	3.53%
SJWC \| California Pollution Control Financing Authority Revenue Bond
Debt Instrument [Line Items]
Total debt	$ 630,000	575,000
SJWC \| Senior notes
Debt Instrument [Line Items]
Total debt	$ 560,000	505,000
SJWC \| Senior notes \| Minimum
Debt Instrument [Line Items]
Rate	3.00%
SJWC \| Senior notes \| Maximum
Debt Instrument [Line Items]
Rate	7.20%
SJWC \| Public Utility, Bonds \| California Pollution Control Financing Authority Revenue Bond
Debt Instrument [Line Items]
Rate	4.75%
Total debt	$ 70,000	70,000
CTWS \| Bank term loans
Debt Instrument [Line Items]
Total debt	$ 12,212	14,389
CTWS \| Bank term loans \| Minimum
Debt Instrument [Line Items]
Rate	4.09%
CTWS \| Bank term loans \| Maximum
Debt Instrument [Line Items]
Rate	4.15%
CWC
Debt Instrument [Line Items]
Total debt	$ 448,653	388,672
CWC \| Senior notes
Debt Instrument [Line Items]
Total debt	$ 330,000	270,000
CWC \| Senior notes \| Minimum
Debt Instrument [Line Items]
Rate	3.07%
CWC \| Senior notes \| Maximum
Debt Instrument [Line Items]
Rate	6.46%
CWC \| Public Utility, Bonds \| Connecticut Innovations Revenue Bonds, variable rate
Debt Instrument [Line Items]
Total debt	$ 22,050	22,050
CWC \| Bank term loans
Debt Instrument [Line Items]
Total debt	$ 96,295	96,295
CWC \| Bank term loans \| Minimum
Debt Instrument [Line Items]
Rate	4.04%
CWC \| Bank term loans \| Maximum
Debt Instrument [Line Items]
Rate	4.75%
CWC \| State revolving fund loans \| State revolving fund loans
Debt Instrument [Line Items]
Rate	2.00%
Total debt	$ 308	327
TWC
Debt Instrument [Line Items]
Total debt	$ 149,000	109,000
TWC \| Senior notes
Debt Instrument [Line Items]
Rate	6.27%
Total debt	$ 15,000	15,000
TWC \| Bank term loans
Debt Instrument [Line Items]
Total debt	$ 105,000	65,000
TWC \| Bank term loans \| Minimum
Debt Instrument [Line Items]
Rate	4.01%
TWC \| Bank term loans \| Maximum
Debt Instrument [Line Items]
Rate	6.68%
TWC \| Seller financing debt
Debt Instrument [Line Items]
Total debt	$ 29,000	29,000
Interest rate effective percentage	5.61%
MWC
Debt Instrument [Line Items]
Total debt	$ 101,336	72,763
MWC \| Bank term loans
Debt Instrument [Line Items]
Total debt	$ 85,000	60,000
MWC \| Bank term loans \| Minimum
Debt Instrument [Line Items]
Rate	3.89%
MWC \| Bank term loans \| Maximum
Debt Instrument [Line Items]
Rate	6.47%
MWC \| State revolving fund loans \| State revolving fund loans
Debt Instrument [Line Items]
Total debt	$ 16,336	$ 12,763
MWC \| State revolving fund loans \| State revolving fund loans \| Minimum
Debt Instrument [Line Items]
Rate	0.00%
MWC \| State revolving fund loans \| State revolving fund loans \| Maximum
Debt Instrument [Line Items]
Rate	2.23%

Cover Page - USD ($) $ in Billions	12 Months Ended
Cover Page - USD ($) $ in Billions	Dec. 31, 2025	Feb. 19, 2026	Jun. 30, 2025
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2025
Document Transition Report	false
Entity File Number	001-8966
Entity Registrant Name	H2O AMERICA
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0066628
Entity Address, Address Line One	110 West Taylor Street,
Entity Address, City or Town	San Jose,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95110
City Area Code	(408)
Local Phone Number	279-7800
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	HTO
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction Flag	false
Entity Shell Company	false
Entity Public Float			$ 1.8
Entity Common Stock, Shares Outstanding		36,164,486
Documents Incorporated by Reference	Portions of the registrant’s Proxy Statement relating to the registrant’s Annual Meeting of Stockholders are incorporated by reference into Part III of this Form 10-K where indicated.
Entity Central Index Key	0000766829
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Amendment Flag	false

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating activities:
Net income	$ 102,578	$ 93,967	$ 84,987
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	120,490	115,050	108,138
Deferred income taxes	5,183	10,355	(8,510)
Stock-based compensation	6,444	5,623	4,647
Allowance for equity funds used during construction	(6,237)	(2,362)	(2,114)
Loss on sale of nonutility properties and other assets	0	572	0
Changes in operating assets and liabilities, net of acquired assets and liabilities:
Accounts receivable and accrued unbilled revenue	(3,234)	(12,663)	(10,869)
Accounts payable and other current liabilities	9,280	4,241	492
Accrued groundwater extraction charges, purchased water and power	4,204	639	4,772
Tax receivable and payable, and other accrued taxes	(18,280)	(18,355)	(22,415)
Postretirement benefits	(5,682)	(4,400)	(1,549)
Regulatory assets and liabilities excluding income tax temporary differences and postretirement benefits	7,374	(1,812)	12,278
Up-front service concession payments	0	(23,900)	0
Other noncurrent assets and liabilities	26,114	21,042	20,756
Proceeds from litigation settlement, net	7,823	0	0
Other changes, net	(11,254)	7,529	218
Net cash provided by operating activities	244,803	195,526	190,831
Investing activities:
Company-funded	(489,607)	(353,029)	(271,772)
Contributions in aid of construction	(30,146)	(24,179)	(16,855)
Additions to nonutility assets and real estate investments	0	(29)	(24,244)
Payments for business acquisitions	0	0	(7,537)
Cost to retire utility plant, net of salvage	(3,149)	(3,430)	(2,097)
Proceeds from sale of real estate investments and release of escrow deposit	2,801	40,572	233
Net cash used in investing activities	(520,101)	(340,095)	(322,272)
Financing activities:
Borrowings from lines of credit	436,530	242,000	146,415
Repayments of lines of credit	(468,821)	(295,260)	(134,493)
Long-term borrowings	185,167	185,329	70,000
Repayments of long-term borrowings	(3,861)	(48,975)	(4,347)
Dividends paid	(58,645)	(52,132)	(47,905)
Receipts of advances and contributions in aid of construction	59,902	33,070	22,425
Refunds of advances for construction	(4,404)	(2,963)	(2,763)
Issuance of common stock, net of issuance costs	122,808	85,008	80,659
Proceeds from litigation settlement, net	16,949	0	0
Other changes, net	(755)	(117)	(1,171)
Net cash provided by financing activities	284,870	145,960	128,820
Net change in cash and cash equivalents	9,572	1,391	(2,621)
Cash and cash equivalents, beginning of year	11,114	9,723	12,344
Cash and cash equivalents, end of year	20,686	11,114	9,723
Cash paid (refunded) during the year for:
Interest	79,428	73,268	67,508
Interest, net of amounts capitalized	72,093	69,744	64,608
Income taxes	3,238	(598)	23,020
Supplemental disclosure of non-cash activities:
Accrued payables for additions to utility plant	48,146	41,692	35,904
Utility property installed by developers	3,686	2,465	3,341
Proceeds receivable from sale of real estate investments	0	2,801	0
Accrued selling expenses on sale of real estate investments	0	2,177	0
Seller financing in asset acquisition, net of discount	$ 0	$ 0	$ 15,400

Acquisitions	12 Months Ended
Acquisitions	Dec. 31, 2025
Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]
Acquisitions	Acquisitions Quadvest acquisition On July 7, 2025, the Company, through its indirect subsidiary, TWC, entered into an asset purchase agreement (the “Regulated Business APA”)”, with Quadvest, L.P. (“Quadvest Retail”) and the Company, as guarantor, pursuant to which, and subject to the terms and conditions set forth therein, Quadvest Retail has agreed to sell, and TWC has agreed to acquire, substantially all of the assets of Quadvest L.P. related to the operation of Quadvest L.P.’s water and sewer utility business at a purchase price consisting of a base amount of $483,600, with certain adjustments based on capital expenditures (the “Regulated Business Transaction”). The Regulated Business Transaction will be subject to the satisfaction of various closing conditions set forth in the Regulated Business APA, including satisfaction of the closing conditions with respect to the Wholesale Business Transaction described below. Concurrently on July 7, 2025, the Company, its indirect subsidiaries, TWOS and TWC (together with the Company and TWOS, the “Purchasers”), entered into another asset purchase agreement (the “Wholesale Business APA”), with Quadvest Retail and its affiliate, Quadvest Wholesale, LLC, (“Quadvest Wholesale”) pursuant to which, and subject to the terms and conditions set forth therein, Quadvest Wholesale has agreed to sell, and TWOS has agreed to acquire substantially all of the assets of Quadvest Wholesale related to the operation of Quadvest Wholesale’s wholesale water and sewer business at a purchase price consisting of a base amount of $56,400, with certain adjustments based on capital expenditures (the “Wholesale Business Transaction”). The Wholesale Business Transaction will be subject to the satisfaction of various closing conditions set forth in the Wholesale Business APA, including the simultaneous closing of the Regulated Business Transaction described above. On July 9, 2025, TWC filed a request with the PUCT to use FMV to support its acquisition of Quadvest Retail. On August 7, 2025, the PUCT appointed three appraisers to determine the FMV. In December 2025, TWC received the appraised FMV from the PUCT-appointed appraisers for the assets of Quadvest Retail. In accordance with Texas’ FMV statute, the purchase price of $483.6 million will serve as the ratemaking rate base. TWC filed its STM application with the PUCT in January 2026.

- Definition

The entire disclosure for business combination.

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