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):    September 28, 2005        
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                         CALIFORNIA WATER SERVICE GROUP
                         ------------------------------
             (Exact name of registrant as specified in its charter)



          Delaware                    1-13883              77-0448994
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(State or other jurisdiction        (Commission         (I.R.S. Employer
     of Incorporation)              File Number)       Identification No.)


     1720 North First Street, San Jose, CA.                      95112
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   (Address of principal executive offices)                   (Zip Code)

Registrant's telephone number, including area code     1-408-367-8200
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                                 Not Applicable
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          (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 (see General Instruction A.2. below):

[ ]  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 ))



Item 5.02 Appointment of Acting Principal Officers


     On September 28, 2005, California Water Service Group announced that it had
named  John S.  Tootle,  Corporate  Counsel,  as Acting  Vice  President,  Chief
Financial  Officer and  Treasurer  and placed  Richard D. Nye on  administrative
leave  following  the  filing of a civil  suit by the  Securities  and  Exchange
Commission  against Mr. Nye;  the suit  relates to a position  that Mr. Nye held
previously at another company.

     Mr. Tootle,  age 51, served as California  Water Service Group's  Corporate
Counsel  prior to assuming this  position.  He joined the company in May of 2000
when it acquired  Dominguez Services  Corporation,  where he had served as Chief
Financial Officer since 1987. Before joining  Dominguez  Services  Corporation's
executive team, Mr. Tootle served as Chief Financial Officer for United Business
Interiors,  Senior Internal  Auditor for Republic  Corporation,  and Auditor for
PricewaterhouseCoopers.   Mr.  Tootle  is  an  attorney  and  certified   public
accountant.  As Corporate  Counsel,  Mr. Tootle has benefits similar to those of
the officers of the company. The terms of his employment have not changed.

     Mr. Tootle has no family relationship with any director or other officer of
the company. He has had no material interest in any transaction with the company
since the beginning of the company's last fiscal year.

     A copy of the news release  issued on  September  28, 2005  announcing  the
management change is filed herewith as Exhibit 99.1


(c) Exhibits.

     99.1    The news  release  issued  by  California  Water  Service  Group on
             September 28, 2005.


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                                   SIGNATURES

     Pursuant to the requirement of the Securities and 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
                                    ------------------------------
                                            (Registrant)



Date: September 29, 2005            By:  /s/ John S. Tootle
                                       ----------------------------------------
                                         John S. Tootle
                                         Acting Vice President,
                                         Chief Financial Officer and Treasurer


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                                  Exhibit Index


Exhibit No.                                 Description
-----------                                 -----------

  99.1             Press  release of the  registrant  dated  September  28, 2005
                   which announces management changes.


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