Exhibit 23.1



CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


The Board of Directors and Stockholders
California Water Service Group:


We consent to  incorporation  by reference in the  registration  statements (No.
333-103721)  on Form S-3 and (No.  333-60810 and No.  333-127495) on Form S-8 of
California  Water Service Group of our reports dated March 9, 2006, with respect
to the  consolidated  balance  sheets  of  California  Water  Service  Group and
subsidiaries  as of  December  31, 2005 and 2004,  and the related  consolidated
statements of income,  common stockholders' equity and comprehensive income, and
cash flows for each of the years in the  three-year  period  ended  December 31,
2005,  management's  assessment of the  effectiveness  of internal  control over
financial  reporting as of December 31, 2005, and the  effectiveness of internal
control over financial reporting as of December 31, 2005.



/s/ KPMG LLP
Mountain View, California
March 9, 2006