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): November 20, 2019

CALIFORNIA WATER SERVICE GROUP

(Exact name of Registrant as Specified in its Charter)

(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:

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. ¨

On November 20, 2019, the Board of Directors (the “Board”) of California Water Service Group (the “Company”) voted to elect Patricia K. Wagner and Scott L. Morris, to the Board, effective November 20, 2019.

There are no arrangements or understandings between Ms. Wagner or Mr. Morris and any other person pursuant to which Ms. Wagner or Mr. Morris were selected as directors. There is no information that is required to be disclosed with respect to Ms. Wagner or Mr. Morris pursuant to Item 404(a) of Regulation S-K.

On November 20, 2019, the Company issued a press release announcing the election of Ms. Wagner and Mr. Morris to the Board. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated into this Item 5.02 by this reference.

On November 20, 2019, the Board voted to increase the size of the Board from nine to eleven directors, effective November 20, 2019.

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.

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.