SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                              ---------------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933


                         CALIFORNIA WATER SERVICE GROUP
                         ------------------------------
             (Exact name of registrant as specified in its charter)


                                    Delaware
                                    --------
         (State or other jurisdiction of incorporation or organization)


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


      1720 North First Street, San Jose, California             95112-4598
      ---------------------------------------------             ----------
      (Address of principal executive offices)                  (Zip Code)


             California Water Service Group Long Term Incentive Plan
             -------------------------------------------------------
                            (Full Title of the Plan)

                                 Peter C. Nelson
                         California Water Service Group
                             1720 North First Street
                             San Jose, CA 95112-4598
                             -----------------------
                     (Name and address of agent for service)

                                 (408) 367-8200
                                 --------------
           Telephone Number, Including Area Code, of Agent For Service









                         CALCULATION OF REGISTRATION FEE


- ----------------------- ------------------ ------------------------- ------------------------ ------------------
                        Amount                                       Proposed Maximum
Title Of Securities     To Be              Proposed Maximum          Aggregate Offering       Amount Of
 To Be Registered       Registered         Offering Price Per Share  Price                    Registration Fee
- ----------------------- ------------------ ------------------------- ------------------------ ------------------
                                                                                  

Common Stock, par
value $0.01 per share    1,388,500 shares         $25.35 1/             $35,198,475.00 2/         See below
- ----------------------- ------------------ ------------------------- ------------------------ ------------------
Common Stock, par
value $0.01 per share    58,000 shares 3/           $25.94                $1,504,520.00           See below
- ----------------------- ------------------ ------------------------- ------------------------ ------------------
Common Stock, par
value $0.01 per share    53,500 shares 4/          $23.0625               $1,233,843.75         $9,500.00 2/
- ----------------------- ------------------ ------------------------- ------------------------ ------------------

<FN>
1/ Estimated  solely for the purpose of computing the amount of the registration
fee  pursuant  to Rule  457(c) and (h) based on the  average of the high and low
prices of the Group's common stock as reported on the New York Stock Exchange on
May 4, 2001. In addition to the common stock set forth in the table,  the amount
to be registered includes an indeterminate number of shares issuable pursuant to
stock splits and stock dividends in accordance with Rule 416(b).

2/ Calculated on the basis of the maximum  aggregate  offering  price of all the
securities listed, pursuant to Rule 457(o).

3/ Represents  shares of Common Stock  underlying  option grants made  effective
January 2, 2001 at an  exercise  price of $25.94  per  share,  25% of which will
become exercisable on January 2, 2002.

4/ Represents  shares of Common Stock  underlying  option grants made  effective
June 28, 2000 at an  exercise  price of  $23.0625  per share,  25% of which will
become exercisable on June 28, 2001.
</FN>



                                       2





                                     Part I

    Note: The document(s) containing the information specified by Part I of Form
S-8 will be sent or given to employees as specified by Rule 428(b)(1).

                                     Part II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

    The Group hereby  incorporates by reference in this  registration  statement
the following documents:

    1) Annual Report on Form 10-K for the fiscal year ended December 31, 2000;

    2) The description of the Group's Common Stock set forth in the Registration
Statement  on Form 8-A under  Section  12(b) of the  Exchange Act and any future
amendment or report filed for the purpose of updating such description; and

    3) The description of Preferred  Stock Purchase  Rights in the  Registration
Statement on Form 8-A under Section 12(b) of the Exchange Act filed February 13,
1998 and any future  amendment or report filed for the purpose of updating  such
description.

    All documents filed by the Group with the Commission  after the date of this
Registration Statement under Sections 13(a), 13(c), 14 and 15(d) of the Exchange
Act, and before the Group files a  post-effective  amendment  which reports that
all  securities  offered in this  Registration  Statement  have been sold, or to
deregister all unsold  securities,  shall also be deemed to be  incorporated  by
reference and to be part of this  Registration  Statement from the dates we file
each of those documents.

Item 4.  Description of Securities.

    The class of securities to be offered is registered  under Section 12 of the
Exchange Act.

Item 5.  Interests of Named Experts and Counsel.

    Not applicable.

Item 6.  Indemnification of Officers and Directors.

    The Group's Certificate of Incorporation  provides that the liability of the
directors of the Group, both to the Group and to its stockholders,  for monetary
damages,  including  liability for breach of fiduciary duty, shall be eliminated
to the fullest  extent  permissible  under  Delaware law. The  Certificate  also
provides  that the Group shall  indemnify any person who is or was a party or is
threatened to be made a party to any  proceeding by reason of the fact that such
person

                                       3




is or was an agent of the Group, to the fullest extent  permitted by Section 145
of the Delaware General Corporation Law.

    The Group also maintains officers and director's  liability insurance in the
amount of $20,000,000.

Item 7.  Exemption from Registration Claimed.

    Not applicable.

Item 8.  Exhibits.

    The Exhibit Index attached hereto is incorporated by reference.

Item 9.  Undertakings.

    (a) The undersigned registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this registration statement:

               (i) To include any prospectus required by Section 10(a)(3) of the
Securities Act of 1933;

               (ii) To reflect  in the  prospectus  any facts or events  arising
after the  effective  date of the  registration  statement  (or the most  recent
post-effective  amendment  thereof)  which,  individually  or in the  aggregate,
represent a fundamental  change in the information set forth in the registration
statement;

               (iii) To include any  material  information  with  respect to the
plan of distribution not previously  disclosed in the registration  statement or
any material change to such information in the registration statement;

         Provided,  however,  that  paragraphs  (a)(1)(i) and  (a)(1)(ii) do not
apply if the information  required to be included in a post-effective  amendment
by those  paragraphs is contained in periodic reports filed with or furnished to
the Commission by the registrant  pursuant to Section 13 or Section 15(d) of the
Exchange Act that are incorporated by reference in the registration statement.

         (2) That,  for the  purpose  of  determining  any  liability  under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof.

         (3) To remove from registration by means of a post-effective  amendment
any of the securities being registered which remain unsold at the termination of
the offering.


                                       4






    (b) The  undersigned  registrant  hereby  undertakes  that,  for purposes of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual  report  pursuant to Section  13(a) or Section 15(d) of the
Exchange Act (and, where  applicable,  each filing of an employee benefit plan's
annual  report   pursuant  to  Section  15(d)  of  the  Exchange  Act)  that  is
incorporated by reference in the registration  statement shall be deemed to be a
new registration  statement relating to the securities offered therein,  and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof.

    (c) Insofar as indemnification  for liabilities arising under the Securities
Act of 1933 may be permitted to directors,  officers and controlling  persons of
the  registrant  pursuant  to  the  foregoing  provisions,   or  otherwise,  the
registrant  has been advised that in the opinion of the  Securities and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore,  unenforceable. In the event that a claim for indemnification
against such  liabilities  (other than the payment by the registrant of expenses
incurred or paid by a director,  officer or controlling person of the registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director,  officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been  settled by  controlling  precedent,  submit to a court of  appropriate
jurisdiction the question whether such  indemnification  by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.



                                       5




                                   Signatures


The Registrant.

    Pursuant to the requirements of the Securities Act of 1933, as amended,  the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized, in the City of San Jose, State of California, on May 7, 2001.


                                     CALIFORNIA WATER SERVICE GROUP



                                     By: /s/ Peter C. Nelson
                                         -------------------
                                         Peter C. Nelson
                                         President and Chief Executive Officer



                                       6




                                POWER OF ATTORNEY



    The  officers  and  directors  of  California   Water  Service  Group  whose
signatures appear below hereby constitute and appoint Peter C. Nelson and Gerald
F. Feeney,  and each of them, their true and lawful  attorneys and agents,  with
full power of substitution, each with power to act alone, to sign and execute on
behalf of the undersigned any amendment or amendments (including  post-effective
amendments)  to this  Registration  Statement  on Form S-8 and to file the same,
with all exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto each of said attorneys-in-fact
and agents full power and authority to do everything necessary to accomplish the
foregoing,  as fully to all intents and  purposes as he or she might or could do
in person,  and each of the undersigned  does hereby ratify and confirm all that
each of said attorneys and agents, or their substitutes, shall do or cause to be
done by virtue hereof.


    Pursuant to the requirements of the Securities Act of 1933, as amended, this
Registration  Statement  has  been  signed  by  the  following  persons  in  the
capacities indicated on April 18, 2001



Signature                             Title                                      Date
- ---------                             -----                                      ----
                                                                          
/s/Peter C. Nelson                    President and Chief Executive             April 18, 2001
- ------------------                    Officer (Principal Executive
Peter C. Nelson                       Officer) and Director


/s/Gerald F. Feeney                   Vice President, Chief Financial           April 18, 2001
- -------------------                   Officer and Treasurer (Principal
Gerald F. Feeney                      Financial Officer)

/s/Robert W. Foy                      Chairman of the Board of Directors        April 18, 2001
- ----------------
Robert W. Foy

/s/Edward D. Harris, Jr., M.D.        Director                                  April 18, 2001
- ------------------------------
Edward D. Harris, Jr., M.D.

/s/Robert K. Jaedicke                 Director                                  April 18, 2001
- ---------------------
Robert K. Jaedicke

/s/Richard P. Magnuson                Director                                  April 18, 2001
- ----------------------
Richard P. Magnuson



                                       7






Signature                             Title                                      Date
- ---------                             -----                                      ----

/s/Langdon W. Owen                    Director                                  April 18, 2001
- ------------------
Langdon W. Owen

/s/Linda R. Meier                     Director                                  April 18, 2001
- -----------------
Linda R. Meier

/s/George A. Vera                     Director                                  April 18, 2001
- -----------------
George A. Vera



                                       8





                                  EXHIBIT LIST

4.1      Certificate  of   Incorporation   of  California  Water  Service  Group
         (incorporated  by  reference  to  Exhibit A of the  Registrant's  Proxy
         Statement dated March 18, 1999*)

4.2      Restated  By-laws  of  California  Water  Service  Group as  amended on
         January 26, 2000  (incorporated by reference to Exhibit 3-2 to Form 8-K
         dated January 26, 2000*)

4.3      California  Water Service Group Long Term Incentive Plan  (incorporated
         by reference to Appendix A of the Group's Proxy  Statement  dated March
         17, 2000*)

5        Opinion of counsel as to the legality of securities being registered

23.1     Consent of counsel (included in Exhibit 5)

23.2     Consent of independent auditors

23.3     Consent of independent public accountants

24       Power of attorney  (included  in  signature  page of this  registration
         statement)


- ----------------
*        File No. 001-13883.


                                       9