UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

Current Report Pursuant to Section 13 or 15(d) of
The Securities Exchange Act of 1934

Date of Report (date of earliest event reported): October 30, 2025

CALIFORNIA WATER SERVICE GROUP

(Exact name of Registrant as Specified in its Charter)

Delaware
(State or other jurisdiction
of incorporation)

1-13883
(Commission file number)

77-0448994
(I.R.S. Employer
Identification Number)

1720 North First Street
San Jose, California
(Address of principal executive offices)

95112
(Zip Code)

(408) 367-8200

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Shares, par value $0.01		CWT		New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined by Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 2.02.

Results of Operations and Financial Condition

On October 30, 2025, California Water Service Group (the “Company”) issued a press release (a copy of which is attached hereto as Exhibit 99.1 and incorporated herein by reference) announcing its financial results for the third quarter of 2025, ended September 30, 2025.

As announced, the Company will host a conference call on Thursday, October 30, 2025, at 11:00 am EDT to discuss financial results and management’s business outlook. The financial results announcement contains information about how to access the conference call and webcast. A slide presentation, which includes supplemental information relating to the Company, will be used by management during the conference call. A copy of the slide presentation is attached hereto as Exhibit 99.2 and is incorporated by reference herein. The Exhibits will be posted on the Company’s website at www.calwatergroup.com under the “Investor Relations” tab.

The information furnished pursuant to Item 2.02 of this Current Report shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 9.01.

Financial Statements and Exhibits.

We hereby furnish the following exhibits, which shall not be deemed “filed” for the purposes of Section 18 of the Exchange Act, with this report:

Exhibit No.		Description
99.1		Press Release issued October 30, 2025
99.2		Slide presentation relating to conference call
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	CALIFORNIA WATER SERVICE GROUP


Date: October 30, 2025	By:	/s/ James P. Lynch
	Name:	James P. Lynch
	Title:	Senior Vice President, Chief Financial Officer and Treasurer

CALIFORNIA WATER SERVICE GROUP 8-K