UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                    FORM 10-Q

(Mark One)

 X        QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
- ---       EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2004

                                            OR

         TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934

For the transition period from___________________ to ______________

Commission file number ____1-13883___________________________

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

         Delaware                                        77-0448994
- --------------------------------------------------------------------------------
(State or other jurisdiction                (I.R.S. Employer identification No.)
of incorporation or organization)

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

                                 1-408-367-8200
- --------------------------------------------------------------------------------
              (Registrant's telephone number, including area code)

                                 Not Applicable
- --------------------------------------------------------------------------------
              (Former name, former address and former fiscal year,
                          if changed since last report)

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed  by  Section  13 or 15 (d) of the  Securities  Exchange  Act of 1934
during the preceding 12 months (or for such shorter  period that the  registrant
was  required  to file such  reports),  and (2) has been  subject to such filing
requirements for the past 90 days. Yes X No ___

Indicate by checkmark whether the Registrant is an accelerated filer (as defined
in rule 12b-2 of the Act) Yes X No __

Indicate the number of shares  outstanding  of each of the  issuer's  classes of
common stock, as of the latest practicable date. Common shares outstanding as of
May 3, 2004 - 16,932,046.




TABLE OF CONTENTS

                                                                                        Page
                                                                                      
PART I           Financial Review - Management's Discussion and Analysis and
                 Condensed Consolidated Financial Statements......................        3

 Item 1          Condensed Consolidated Balance Sheets  (unaudited)
                   March 31, 2004 and December 31, 2003...........................        4

                 Condensed Consolidated Statements of Income  (unaudited)
                   For the Three Months Ended March 31, 2004 and 2003.............        5

                 Condensed Consolidated Statements of Cash Flows (unaudited)
                   For the Three Months Ended March 31, 2004 and 2003.............        6

                 Notes to Condensed Consolidated Financial Statements.............        7

Item 2           Management's Discussion and Analysis of Financial Condition
                   and Results of Operations......................................       12

Item 3           Quantitative and Qualitative Disclosure about Market Risk........       21

Item 4           Controls and Procedures..........................................       21


PART II          Other Information

Item 1           Legal Proceedings................................................       22

Item 4           Submission of Matters to a Vote of Security Holders..............       22


Item 6           Exhibits and Reports on Form 8-K.................................       23

                 Signatures.......................................................       24

                 Index to Exhibits................................................       25


                                       2

PART I        FINANCIAL INFORMATION

Item 1.

Financial Statements

         The  condensed  consolidated  financial  statements  presented  in this
         filing on Form 10-Q have been prepared by management and are unaudited.


                                       3



CALIFORNIA WATER SERVICE GROUP
CONDENSED CONSOLIDATED BALANCE SHEETS
Unaudited
(In thousands, except per share data)                       March 31,     December 31,
                                                              2004            2003
                                                           -----------    -----------
                                                                    
ASSETS
Utility plant:
         Utility plant                                     $ 1,089,894    $ 1,078,975
         Less accumulated depreciation and amortization        326,361        319,477
                                                           -----------    -----------
               Net utility plant                               763,533        759,498
                                                           -----------    -----------
Current assets:
         Cash and cash equivalents                               2,086          2,856
         Receivables                                            19,198         23,559
         Unbilled revenue                                        8,115          8,522
         Materials and supplies at average cost                  2,875          2,957
         Taxes and other prepaid expenses                        6,258          5,609
                                                           -----------    -----------
                 Total current assets                           38,532         43,503
                                                           -----------    -----------
Other assets:
         Regulatory assets                                      53,710         53,326
         Other assets                                           18,127         16,708
                                                           -----------    -----------
               Total other assets                               71,837         70,034
                                                           -----------    -----------
                                                           $   873,902    $   873,035
                                                           ===========    ===========

CAPITALIZATION AND LIABILITIES
Capitalization:
         Common stock, $.01 par value                      $       169    $       169
         Additional paid-in capital                             93,748         93,748
         Retained earnings                                     147,533        150,908
         Accumulated other comprehensive loss                     (301)          (301)
                                                           -----------    -----------
               Total common stockholders' equity               241,149        244,524
         Preferred stock                                         3,475          3,475
         Long-term debt, less current maturities               272,042        272,226
                                                           -----------    -----------
               Total capitalization                            516,666        520,225
                                                           -----------    -----------
Current liabilities:
         Current maturities of long-term debt                      904            904
         Short-term borrowings                                   9,800          6,454
         Accounts payable                                       18,264         23,776
         Accrued expenses and other liabilities                 36,606         32,430
                                                           -----------    -----------
               Total current liabilities                        65,574         63,564

Unamortized investment tax credits                               2,925          2,925
Deferred income taxes                                           38,161         38,005
Regulatory and other liabilities                                35,888         35,835
Advances for construction                                      123,372        121,952
Contributions in aid of construction                            91,316         90,529
Commitments and contingencies                                     --             --
                                                           -----------    -----------
                                                           $   873,902    $   873,035
                                                           ===========    ===========
<FN>
See Notes to Condensed Consolidated Financial Statements
</FN>


                                       4

CALIFORNIA WATER SERVICE GROUP
CONDENSED CONSOLIDATED STATEMENTS OF INCOME
Unaudited
(In thousands, except per share data)

For the three months ended:                              March 31,     March 31,
                                                           2004          2003
                                                         --------      --------
Operating revenue                                        $ 60,240      $ 51,310
                                                         --------      --------
Operating expenses:
     Operations                                            41,498        37,761
     Maintenance                                            3,181         3,253
     Depreciation and amortization                          6,518         5,760
     Income taxes                                             958          (553)
     Property and other taxes                               2,694         2,465
                                                         --------      --------
           Total operating expenses                        54,849        48,686
                                                         --------      --------

           Net operating income                             5,391         2,624
                                                         --------      --------
Other income and expenses:
           Non-regulated income, net                          550           612
           Gain on sale of non-utility property                 1           552
                                                         --------      --------
                                                              551         1,164
                                                         --------      --------

           Income before interest expense                   5,942         3,788
                                                         --------      --------
Interest expense:
     Interest expense                                       4,646         4,856
     Less: capitalized interest                               150           300
                                                         --------      --------
           Total interest expense                           4,496         4,556
                                                         --------      --------

Net income (loss)                                        $  1,446      $   (768)
                                                         ========      ========
Earnings per share
     Basic                                               $   0.08      $  (0.05)
                                                         ========      ========
     Diluted                                             $   0.08      $  (0.05)
                                                         ========      ========
Weighted average shares outstanding
     Basic                                                 16,932        15,182
                                                         ========      ========
     Diluted                                               16,953        15,182
                                                         ========      ========
Dividends per share of common stock                      $0.28250      $0.28125
                                                         ========      ========

See Notes to Condensed Consolidated Financial Statements

                                       5



CALIFORNIA WATER SERVICE GROUP
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
Unaudited
(In thousands)

For the three months ended:                                        March 31,   March 31,
                                                                     2004        2003
                                                                   --------    --------
                                                                         
Operating activities
          Net income  (loss)                                       $  1,446    $   (768)
                                                                   --------    --------
          Adjustments to reconcile net income (loss) to net cash
            Provided by operating activities:
                  Depreciation and amortization                       6,518       5,760
                  Deferred income taxes, investment tax credits
                          regulatory assets and liabilities, net       (175)       (342)
                  Gain on sale of non-utility property                   (1)       (552)
                  Changes in operating assets and liabilities:
                          Receivables                                 4,353       3,288
                          Unbilled revenue                              407       1,023
                          Taxes and other prepaid expenses             (649)        828
                          Accounts payable                           (5,512)       (680)
                          Other current assets                           82         134
                          Other current liabilities                   4,176       2,731
                          Other changes, net                         (1,107)     (1,527)
                                                                   --------    --------
                          Net adjustments                             8,092      10,663
                                                                   --------    --------
          Net cash provided by operating activities
                                                                      9,538       9,895
                                                                   --------    --------
Investing activities:
          Utility plant expenditures:
                  Company funded                                     (8,168)    (17,884)
                  Developer funded                                   (3,444)     (6,186)
          Proceeds from sale of non-utility property                      6         588
                                                                   --------    --------
          Net cash used by investing activities                     (11,606)    (23,482)
                                                                   --------    --------
Financing activities:
          Net short-term borrowings                                   3,346      (4,802)
          Issuance (retirement) of long-term debt, net                 (183)     19,710
          Advances for construction                                   2,652       2,610
          Refunds of advances for construction                       (1,223)     (1,259)
          Contributions in aid of construction                        1,528       2,291
          Dividends paid                                             (4,822)     (4,308)
                                                                   --------    --------
          Net cash provided by financing activities                   1,298      14,242
                                                                   --------    --------

Change in cash and cash equivalents                                    (770)        655
Cash and cash equivalents at beginning of period                      2,856       1,063
                                                                   --------    --------
Cash and cash equivalents at end of period                         $  2,086    $  1,718
                                                                   ========    ========
<FN>
See Notes to Condensed Consolidated Financial Statements
</FN>


                                       6

                         CALIFORNIA WATER SERVICE GROUP
              Notes to Condensed Consolidated Financial Statements
                                 March 31, 2004

Note 1.  Organization and Operations
     California  Water  Service  Group (the  Company) is a holding  company that
     provides   water  utility  and  other  related   services  in   California,
     Washington,  New Mexico and Hawaii  through its wholly owned  subsidiaries.
     California  Water  Service  Company (Cal Water),  Washington  Water Service
     Company  (Washington  Water),  New Mexico Water Service Company (New Mexico
     Water) and Hawaii  Water  Service  Company,  Inc.  (Hawaii  Water)  provide
     regulated  utility  services  under  the  rules  and  regulations  of their
     respective State's regulatory commissions.  In addition, these entities and
     CWS   Utility   Services   provide    non-regulated   water   utility   and
     utility-related services.

     The Company  operates  primarily in one business  segment  providing  water
     utility services.


Note 2.  Summary of Significant Accounting Policies
     The  interim  financial  information  is  unaudited.   In  the  opinion  of
     management,  the accompanying  condensed  consolidated financial statements
     reflect all adjustments  that are necessary to provide a fair  presentation
     of the results for the periods  covered.  The  adjustments  consist only of
     normal  recurring  adjustments.  The results  for  interim  periods are not
     necessarily  indicative  of the results of the entire year.  The  condensed
     consolidated  financial  statements  should be read in conjunction with the
     Company's consolidated financial statements for the year ended December 31,
     2003  included in its Form 10-K as filed with the  Securities  and Exchange
     Commission on March 15, 2004.


Note 3.  Stock-based Compensation
     The Company has a stockholder approved Long-Term Incentive Plan that allows
     granting  of  non-qualified  stock  options.  The  Company  has adopted the
     disclosure  requirements  of Statement of  Financial  Accounting  Standards
     (SFAS) No. 123  "Accounting for  Stock-Based  Compensation,"  as amended by
     SFAS  No.  148  "Accounting  for  Stock-Based   Compensation  -  Transition
     Disclosure - An Amendment of FASB  Statement  No. 123," and as permitted by
     SFAS  No.  123,  applies  Accounting   Principles  Board  Opinion  No.  25,
     "Accounting  for Stock Issued to Employees,"  for its plan. All outstanding
     options  had an exercise  price equal to the market  price on the date they
     were  granted.  No  compensation  expense was  recorded for the three month
     periods ended March 31, 2004 and 2003 related to stock options.  No options
     were granted during either period.


                                       7

     The table below illustrates the effect on net income and earnings per share
     as if the company had applied the fair value recognition  provision of SFAS
     No. 123 to employee compensation.


(In thousands, except per share data)
                                                             Three Months Ended
                                                                  March 31
                                                              2004       2003
                                                           ---------   --------
Net income (loss), as reported                             $   1,446      ($768)

Deduct:  Total stock-based employee compensation
     expense determined under fair value
     method for all awards, net of related tax effects            17         21
                                                           ---------   --------
Pro forma net income (loss)                                $   1,429      ($789)
                                                           =========   ========

Earnings (Loss) per share
          Basic - as reported                              $    0.08     ($0.05)
          Basic - pro forma                                $    0.08     ($0.05)

          Diluted - as reported                            $    0.08     ($0.05)
          Diluted - pro forma                              $    0.08     ($0.05)


Note 4.  Seasonal Business
     Due to the seasonal nature of the water  business,  the results for interim
     periods  are not  indicative  of the  results  for a  twelve-month  period.
     Revenue and income are generally higher in the warm, dry summer months when
     water  usage and sales are  greater.  Revenue  and  income are lower in the
     winter months when cooler temperatures and rainfall curtail water usage and
     sales.


Note 5.  Earnings Per Share Calculations
     The computations of basic and diluted earnings per share are noted below.

     Common stock options to purchase  149,250 and 154,500  shares for the three
     months ended March 31, 2004 and 2003, respectively, were outstanding. Stock
     options for 2003 were excluded from the diluted per share  calculation  due
     to their anti-dilutive effect.


                                       8


(In thousands, except per share data)

                                                             Three Months Ended
                                                                  March 31
                                                             2004        2003
                                                           --------    --------
Net income (loss)                                          $  1,446       ($768)

Less preferred dividends                                         38          38
                                                           --------    --------
Net income (loss) available to common stockholders         $  1,408       ($806)
                                                           ========    ========

Weighted average common shares                               16,932      15,182

Dilutive common stock options (treasury method)                  21        --
                                                           --------    --------
Shares used for dilutive computation                         16,953      15,182
                                                           ========    ========

Net income (loss) per share - basic                        $   0.08      ($0.05)
                                                           --------    --------
Net income (loss) per share - diluted                      $   0.08      ($0.05)
                                                           --------    --------


Note 6.  Pension Plan and Other Postretirement Benefits
     The Company provides a qualified defined benefit,  non-contributory pension
     plan  for   substantially   all   employees.   The  Company   makes  annual
     contributions  to fund the amounts accrued for the qualified  pension plan.
     The  Company  also  maintains  an  unfunded,  non-qualified,   supplemental
     executive  retirement  plan.  The costs of the plans are charged to expense
     and utility plant.

     The Company offers medical,  dental, vision and life insurance benefits for
     retirees and their spouses and dependents. Participants are required to pay
     a premium, which offsets a portion of the cost.

     Payments by the Company  related to pension  plan and other  postretirement
     benefits were  $3,812,000 for the three months ended March 31, 2004. Due to
     a  federal  regulation  change,  the  estimated  funding  for 2004 has been
     revised from  $8,235,000 to $7,700,000  for 2004.  The change in funding is
     not expected to impact the expense recorded for 2004.

     The  following  table  lists  components  of the  pension  plans  and other
     postretirement  benefits. The data listed under "pension plan" includes the
     qualified  pension  plan  and  the  non-qualified   executive  supplemental
     retirement  plan.  The data listed under "other  benefits" is for all other
     post retirement benefits.


                                       9

(In thousands)
                                               Three Months Ended March 31
                                           Pension Plan        Other Benefits
                                       ------------------    ------------------
                                         2004       2003       2004       2003
                                       -------    -------    -------    -------
Service cost                           $ 1,137    $   977    $   305    $   221
Interest cost                            1,364      1,353        342        262
Expected return on plan assets          (1,219)    (1,198)       (86)       (50)
Recognized net initial ABO                --         --          N/A        N/A
Recognized net initial APBO                N/A        N/A         69         59
Amortization of prior service cost         424        454         19         16
Recognized net actuarial (gain) loss        34         15         84         61
                                       -------    -------    -------    -------
Net periodic benefit cost              $ 1,740    $ 1,601    $   733    $   569
                                       =======    =======    =======    =======

     ABO - Accumulated benefit obligation
     APBO - Accumulated postretirement benefit obligation

     Postretirement benefit expense for "other benefits" recorded in the first
     quarter of 2004 and 2003 was $388,000 and $345,000, respectively. As of
     March 31, 2004, the Company had a regulatory asset of $7,191,000 related to
     postretirement benefits, which is expected to be recovered through future
     customer rates.

Note 7.  New Accounting Standards
     In December 2003, the FASB issued Interpretation No. 46R, "Consolidation of
     Variable   Interest   Entities"  which  amended   Interpretation   No.  46,
     "Consolidation  of  Variable  Interest  Entities".  The  revision  exempted
     certain entities and modified the effective  dates.  The original  guidance
     issued under  Interpretation  No. 46 in January  2003 is still  applicable.
     Interpretation  No. 46 and  Interpretation  No. 46R  provide  guidance  for
     determining  when a  primary  beneficiary  should  consolidate  a  variable
     interest  entity or  equivalent  structure  that  functions  to support the
     activities of the primary beneficiary. Interpretation No. 46R was effective
     for the period ended March 31, 2004. The adoption of Interpretation No. 46R
     did not impact the Company's financial  position,  results of operations or
     cash flows.

     In January  2004,  the FASB issued  FASB Staff  Position  (FSP) No.  106-1,
     "Accounting   and   Disclosure   Requirements   Related  to  the   Medicare
     Prescription  Drug,  Improvement  and  Modernization  Act of 2003." FSP No.
     106-1,  which  was  effective  for  the  Company's  consolidated  financial
     statements  for the year ended  December 31,  2003,  permits a sponsor of a
     postretirement  health care plan that provides a prescription  drug benefit
     to make a one-time  election  to defer  accounting  for the  effects of the
     Medicare Prescription Drug,  Improvement and Modernization Act of 2003 (the
     Medicare  Act).  In  accordance  with FSP No.  106-1,  the  Company  made a
     one-time  election to defer the  recognition of the impact of FSP No. 106-1

                                       10


     accounting.   Any  measures  of  the  accumulated   postretirement  benefit
     obligation and net periodic postretirement benefit cost in the consolidated
     financial  statements  and footnotes for March 31, 2004 did not reflect the
     effects of the Medicare Act. Currently,  specific authoritative  accounting
     guidance for the federal subsidy is pending and that guidance, when issued,
     may require  the Company to change  previously  reported  information.  The
     Company believes the accounting change will reduce postretirement cost, but
     cannot estimate the impact at this time.


Note 8.  Subsequent Event

     Acquisitions

     On April 30,  2004,  the Company  acquired  the stock of  National  Utility
     Company (NUC) and land from owners of NUC for  approximately  $1,030,000 in
     cash.  The Company plans to retire NUC's stock and merge it into New Mexico
     Water Service Company.  Revenue and net loss for NUC for 2003 were $541,000
     and ($19,000),  respectively.  The purchase price is approximately equal to
     rate base,  and  therefore  the  Company  expects  to record  minimal or no
     goodwill in the transaction.


                                       11

Item 2

MANAGEMENT'S DISCUSSION AND ANALYSIS OF
FINANCIAL CONDITION AND RESULTS OF OPERATIONS

FORWARD LOOKING STATEMENTS

     This quarterly report,  including all documents  incorporated by reference,
     contains  forward-looking  statements within the meaning established by the
     Private Securities Litigation Reform Act of 1995 (Act). The forward-looking
     statements  are  intended  to  qualify  under  provisions  of  the  federal
     securities  laws  for  "safe  harbor"  treatment  established  by the  Act.
     Forward-looking  statements are based on currently  available  information,
     expectations,  estimates,  assumptions and  projections,  and  management's
     judgment about the Company, the water utility industry and general economic
     conditions.  Such words as expects,  intends,  plans, believes,  estimates,
     assumes,  anticipates,  projects, predicts, forecasts or variations of such
     words or similar  expressions  are  intended  to  identify  forward-looking
     statements.  The  forward-looking  statements  are not guarantees of future
     performance.  They are subject to uncertainty and changes in circumstances.
     Actual   results  may  vary   materially   from  what  is  contained  in  a
     forward-looking  statement.  Factors that may cause a result different than
     expected or anticipated include:  governmental and regulatory  commissions'
     decisions;  changes in regulatory commissions' policies and procedures; the
     timeliness of regulatory  commissions'  actions concerning rate relief; new
     legislation;  electric power interruptions;  increases in suppliers' prices
     and the availability of supplies including water and power; fluctuations in
     interest  rates;  changes in  environmental  compliance  and water  quality
     requirements;  acquisitions  and  our  ability  to  successfully  integrate
     acquired companies;  the ability to successfully  implement business plans;
     changes  in  customer  water use  patterns;  the impact of weather on water
     sales and operating  results;  access to sufficient capital on satisfactory
     terms;  civil  disturbances  or terrorist  threats or acts, or apprehension
     about the possible future occurrences of acts of this type; the involvement
     of the United States in war or other hostilities;  restrictive covenants in
     or changes to the credit  ratings on our  current or future debt that could
     increase our financing costs or affect our ability to borrow, make payments
     on debt or pay  dividends;  and, other risks and  unforeseen  events.  When
     considering  forward-looking  statements,  you  should  keep  in  mind  the
     cautionary  statements included in this paragraph.  We assume no obligation
     to provide public updates of forward-looking statements.

CRITICAL ACCOUNTING POLICIES

     We maintain our accounting records in accordance with accounting principles
     generally  accepted in the United  States of America and as directed by the
     regulatory  commissions  to which we are subject.  The process of preparing
     financial  statements  requires  the  use  of  estimates  on  the  part  of
     management.  The  estimates  used by  management  are  based on  historical
     experience  and  an  understanding  of  current  facts  and  circumstances.


                                       12

     Management  believes  that the following  accounting  policies are critical
     because they involve a higher  degree of complexity  and judgment,  and can
     have  a  material  impact  on  our  results  of  operations  and  financial
     condition.

Revenue Recognition
     Revenue  from metered  customers  includes  billings to customers  based on
     monthly  meter  readings  plus an  estimate  for  water  used  between  the
     customer's  last meter reading and the end of the  accounting  period.  The
     unbilled revenue amount is recorded as a current asset on the balance sheet
     under the caption  "Unbilled  Revenue."  At March 31,  2004,  the  unbilled
     revenue  amount was  $8,115,000  and at December 31,  2003,  the amount was
     $8,522,000.  The unbilled  revenue  amount is generally  higher  during the
     summer months when water sales are higher.  The amount recorded as unbilled
     revenue varies depending on water usage in the preceding period; the number
     of days between meter reads for each billing cycle;  and the number of days
     between each cycle's meter reading and the end of the accounting cycle.

     Flat rate  customers  are billed in advance at the beginning of the service
     period.  The revenue is prorated so that the portion of revenue  applicable
     to the current accounting period is included in that period's revenue.  The
     portion related to a subsequent  accounting  period is recorded as unearned
     revenue on the balance  sheet and  recognized as revenue when earned in the
     subsequent accounting period. The unearned revenue liability was $2,182,000
     at March 31, 2004 and  $2,127,000 at December 31, 2003.  This  liability is
     included in "accrued expenses and other liabilities" on the balance sheet.

Expense Balancing and Memorandum Accounts
     Expense balancing accounts and memorandum  accounts  (offsetable  expenses)
     represent recoverable costs incurred, but not billed to our customers.  The
     amounts  included in these accounts relate to rate increases  charged to us
     by suppliers of purchased water and purchased  power, and increases in pump
     taxes and only apply for our  California  regulated  operations.  We do not
     record expense balancing or memorandum accounts in our financial statements
     as revenue,  nor as a receivable,  until the  California  Public  Utilities
     Commission  (CPUC) and has  authorized  recovery  of the  higher  costs and
     customers  have  been  billed.  Therefore,  a timing  difference  may occur
     between  when  costs  are  recognized  and the  recognition  of  associated
     revenues.  The balancing and memorandum accounts are only used to track the
     higher costs outside of the financial statements. The cost increases, which
     are beyond our control,  are referred to as "offsetable  expenses"  because
     under certain  circumstances  they are recoverable from customers in future
     offset  rate  increases.  The  amounts  requested  may  not  be  ultimately
     collected  through  rates,  as amounts may be disallowed  during the review
     process or subject to an earnings  test.  While the  adjustments  would not
     impact  previously  recorded  amounts,  the  adjustments  may change future
     earnings and cash flows. The cumulative net amount in the expense balancing
     accounts  and  memorandum  accounts as of March 31, 2004 was  approximately
     $9,100,000.  This amount includes  certain amounts that have been filed for
     recovery  but not yet been  authorized,  or amounts  that have not yet been
     filed for recovery.  See Regulatory  Matters for cumulative net balances of
     expense  balancing and memorandum  accounts which have been  authorized for
     recovery.

                                       13

Regulated Utility Accounting
     Because we operate extensively in a regulated  business,  we are subject to
     the provisions of SFAS No. 71, "Accounting for the Effects of Certain Types
     of Regulation."  Regulators establish rates that are expected to permit the
     recovery of the cost of service and a return on investment.  In the event a
     portion of our operations  were no longer subject to the provisions of SFAS
     No. 71, we would be  required to write off  related  regulatory  assets and
     liabilities  that are not  specifically  recoverable and determine if other
     assets might be  impaired.  If a regulatory  commission  determined  that a
     portion of our assets were not  recoverable in customer  rates, we would be
     required to  determine if we had  suffered an asset  impairment  that would
     require a  write-down  in the  assets'  valuation.  There have been no such
     asset impairments as of March 31, 2004.

Income Taxes
     Significant judgment by management is required in determining the provision
     for income taxes.  The  preparation of  consolidated  financial  statements
     requires the  estimation  of income tax expense.  The process  involves the
     estimating  of current  tax  exposure  together  with  assessing  temporary
     differences  resulting from different  treatment of certain items,  such as
     depreciation,  for tax and financial statement reporting. These differences
     result in deferred  tax assets and  liabilities,  which are reported in the
     consolidated  balance  sheet.  We must  also  assess  the  likelihood  that
     deferred tax assets will be recovered in future taxable income,  and to the
     extent recovery is unlikely, a valuation allowance would be recorded.  If a
     valuation allowance were required,  it could significantly  increase income
     tax expense. In management's view, a valuation allowance is not required at
     March 31, 2004.

Pension Benefits
     We incur costs associated with our pension and  postretirement  health care
     benefits plans.  To measure the expense of these benefits,  management must
     estimate  compensation  increases,  mortality  rates,  future  health  cost
     increases  and  discount  rates used to value  related  liabilities  and to
     determine appropriate funding. Different estimates used by management could
     result in significant  variances in the cost recognized for pension benefit
     plans.  The  estimates  used are based on  historical  experience,  current
     facts, future expectations and  recommendations  from independent  advisors
     and actuaries.  We use an investment  advisor to provide advice in managing
     the plan's  investments.  We  anticipate  any  increase  in funding for the
     pension and postretirement  health care benefits plans will be recovered in
     future customer rates.


                                       14

RESULTS OF FIRST QUARTER 2004 OPERATIONS COMPARED TO FIRST QUARTER 2003
OPERATIONS

Summary
     First  quarter net income was  $1,446,000,  equivalent  to $0.08 per common
     share on a diluted  basis  compared to a loss of  ($768,000) or ($0.05) per
     share on a diluted basis in the first quarter of 2003. The primary  drivers
     were  increases  in  rates  and new  customers;  partially  offset  by cost
     increases  for  purchased  water,  income  taxes,  depreciation  and  other
     expenses.

Operating Revenue
     Operating revenue increased $8,930,000 or 17% to $60,240,000.  As disclosed
     in the following table, most of the increase was due to increases in rates.
     Weather  impact was mixed during the  quarter,  as January and February had
     lower  temperatures and higher rainfall  contrasted by higher  temperatures
     and lower rainfall in March.  We experienced an increase in water usage, as
     water usage increased 10% above the prior year,  with the largest  increase
     in March, increasing 19%.

     The factors that  impacted the  operating  revenue for the first quarter of
     2004 are presented in the following table:

         Rate increases                                               $6,977,000
         Usage by new customers                                        1,626,000
         Increase in usage by existing customers                         327,000
                                                                      ----------
              Net operating revenue increase                          $8,930,000
                                                                      ==========


         The components of the rate increases are listed in the following table:

         2001 General Rate Case (GRC)                                 $2,423,000
         Bakersfield Treatment Plant                                   1,158,000
         Purchased water offset                                          953,000
         2001 GRC catch up                                               890,000
         Step rates                                                      738,000
         Balancing accounts                                              530,000
         2002 GRC                                                        163,000
         Hawthorne                                                       122,000
                                                                      ----------
              Total increase in rates                                 $6,977,000
                                                                      ==========

     Usage  by new  customers  includes  $703,000  for  Hawaii  Water  as  these
     operations were acquired in May 2003 and includes  $380,000 for the City of
     Commerce as a lease arrangement was entered into in July 2003.

                                       15

Total Operating Expenses
     Total operating  expenses were $54,849,000 for the three months ended March
     31, 2004 versus $48,686,000 for the same period in 2003, a 13% increase.

     Water production  expense consists of purchased water,  purchased power and
     pump  taxes.  It  represents  the  largest  component  of  total  operating
     expenses,  accounting for  approximately  40% of total operating  expenses.
     Water production expenses increased 12% compared to last year.

     Sources of water production for California operations as a percent of total
     water production are listed on the following table:

                                                              Three Months Ended
                                                                    March 31
                                                               -----------------
                                                               2004         2003
                                                               ----         ----
             Well production                                     40%         48%
             Purchased                                           56%         51%
             Surface                                              4%          1%
                                                                ---         ---
             Total                                              100%        100%
                                                                ===         ===

     Washington Water, New Mexico Water and Hawaii Water obtain all of their
     water supply from wells. The components of water production costs are shown
     in the table below:

                                       Three Months Ended March 31
                                       ---------------------------
                                            2004          2003        Change
                                        -----------   -----------   -----------
             Purchased water            $16,361,000   $14,402,000   $ 1,959,000
             Purchased power              3,595,000     3,623,000       (37,000)
             Pump taxes                   1,205,000       928,000       277,000
                                        -----------   -----------   -----------
                  Total                 $21,161,000   $18,962,000   $ 2,199,000
                                        ===========   ===========   ===========

     Purchased  water cost  increased  due to higher  wholesale  water  rates in
     several  districts  and  higher  usage  of  purchased  water.  Included  in
     purchased  water was an  additional  expense  of  $840,000  to  revise  the
     estimated  settlement cost to $1,571,000 related to the previously reported
     meter malfunction at the wholesale supplier in the Stockton  district.  The
     estimate  was  revised  after  completion  of  a  study  by a  third  party
     contracted by us. At this time, settlement  negotiations have not yet begun
     with the wholesale  supplier  (Stockton East Water  District) and the other
     primary  buyer  (City  of  Stockton),  therefore  final  resolution  may be
     different from our estimates. Also, included in purchased water is a credit
     of $1,381,000  received from certain  wholesale  suppliers for our southern
     California  districts.  The  credits  were due to  adjustments  by  certain
     wholesale  suppliers to all participants for the difference  between actual
     costs and billed costs for 2003. For the three months ended March 31, 2003,
     we did not accrue any additional  amounts related to the meter  malfunction
     and  recorded  $123,000 of credits  from  wholesale  suppliers.  Pump taxes
     increases  primarily due to higher well  production in one district,  where
     pump tax rates are the highest of all of our districts.

                                       16


     Payroll expense  increased  $590,000.  Wages for union employees  increased
     1.5% effective January 1, 2004. Overall,  payroll costs increased 5% due to
     increases  in the  number of  employees,  higher  wage rates and the Hawaii
     Water   acquisition.   Pension   costs   increased   $123,000   or  7%  and
     employee/retiree  medical  costs  increased  $282,000  or 16%. At March 31,
     2004,  there  were 816  employees  and at March 31,  2003,  there  were 797
     employees.

     Insurance/property  claims for the quarter increased $302,000. This was due
     primarily  to flood  damage  caused by a pipe  breakage in one district and
     higher insurance premiums.

     Maintenance  expense was  essentially  flat for the quarter ended March 31,
     2004,  decreasing  $72,000,  or 2%.  Depreciation and amortization  expense
     increased  $758,000 or 13% because of 2003  capital  expenditures.  A major
     component of the  depreciation  expense increase relates to the Bakersfield
     Treatment  Plant,  which began operations in the second quarter of 2003 and
     added $438,000 to depreciation expense in the first quarter of 2004.

     Federal and state income taxes  increased  $1,511,000  due to the change in
     taxable  income.  The effective tax rate was 40% in the current quarter and
     42% for the prior year's quarter.

Other Income and Expense
     Other income was $551,000 for the quarter  ended March 31, 2004 compared to
     $1,164,000,  a decrease  of  $613,000.  Gains from  property  sales for the
     quarter were minimal compared to gains of $552,000 in 2003.

Interest Expense
     Total interest  expense  decreased  $60,000 or 1%. This decrease was due to
     lower  interest  expense  on long term debt as a result  of  refinancing  a
     portion of the debt in 2003 at lower rates. In addition, average short term
     borrowings on our credit  facilities  were lower than last year.  Partially
     offsetting  this  decrease  was  a  decline  in  capitalized  interest,  as
     construction  work in progress  amounts were lower in the first  quarter of
     2004 as compared to the first quarter of 2003.

REGULATORY MATTERS
Rate Case Proceedings
     Filings  that were  approved  in 2003 were  disclosed  in the  Management's
     Discussion and Analysis section of our annual report on Form 10-K for 2003.
     These  approved  filings impact 2004 revenues  because  revenue is recorded
     based  on  billings  to  customers  (See  Results  of  First  Quarter  2004
     Operations Compared to First Quarter 2003 Operations - Operating Revenue).

     In 2004, Cal Water received  approval from the CPUC for step rate increases
     of  $4,433,000  on an annual basis,  of which  $3,902,000  was effective in
     January 2004 and $531,000 was effective in April 2004.

                                       17


     In February 2004, the CPUC authorized an advice letter for $718,000 for one
     district  related to increase  purchased  water rates.  The rate change was
     effective in February 2004 and will be collected over the next 12 months.

     In April 2004, Cal Water received  authorization  from the CPUC on its 2002
     GRC. The GRC included four districts and will increase rates  $3,573,000 on
     an annual basis, effective April 2004.

     Cal Water  recovered  certain  amounts  being  tracked in off balance sheet
     expense  balancing  and  memorandum  account.  Approvals  to recover  these
     amounts were  received in 2003.  (See  "Expense  Balancing  and  Memorandum
     Accounts" section in Critical  Accounting  Policies.) The amounts remaining
     to be  recovered  from these  approved  filings as of December 31, 2003 and
     March 31, 2004 were $2,760,000 and $2,230,000, respectively.

     Cal Water has  pending its 2003 GRC filing  covering  two  districts  and a
     filing for  recovery of  balancing  accounts.  We are unable to predict the
     timing and final amount of these filings at this time.

     Cal Water is  planning to submit its 2004 GRC filings in the 3rd quarter of
     2004. We are unable to predict the timing and final amount of these filings
     at this time.

     New Mexico Water is planning to file for rate increases for its waste water
     operations  in 2004 and Hawaii  Water has  submitted  a rate filing for its
     water  operations  in 2004.  We are unable to predict  the timing and final
     amount of these filings at this time.  Washington  Water is not planning to
     submit a rate filing during 2004.


LIQUIDITY
Short-term and Long-term Debt
     Short-term bank borrowings were $9,800,000 at March 31, 2004 and $6,454,000
     at December 31, 2003.  California  Water  Service  Group has a  $10,000,000
     credit facility,  which includes Washington Water, New Mexico Water, Hawaii
     Water and CWS Utility  Services  and had  borrowed  $4,700,000  against the
     facility at March 31, 2004. Cal Water has a $45,000,000 credit facility and
     had  borrowed  $5,100,000  against  the  facility  at March  31,  2004.  In
     addition,  a $500,000  letter of credit is outstanding  under the facility,
     which reduces  amounts  available for  borrowing.  Both  agreements  have a
     requirement for balances to be below certain  thresholds for 30 consecutive
     days each calendar  year. We met this  requirement  in the first quarter of
     2004 for both agreements. At March 31, 2004, we were in compliance with the
     covenants of both facilities.

     There were no additions to long term debt and we made principal payments of
     $183,000 during the three months period ended March 31, 2004.

                                       18

     Debt Credit Ratings

     Cal Water's debt is rated A2 by Moody's  Investors Service (Moody's) and A+
     by Standard & Poor's  (S&P).  The rating from  Moody's  was  downgraded  in
     February 2004 from A1 to A2. The rating from S&P was  unchanged  during the
     quarter  and the last rating  change from S&P was in the fourth  quarter of
     2002.

Common Stock Issuance and Treasury Stock
     The Company has  $74,062,500  in  securities  under the shelf  registration
     filed with the SEC in 2003, which are available for future issuance.

Dividends, Book Value and Shareholders
     The first quarter  common stock  dividend was paid on February 20, 2004, at
     $0.2825 per share  compared to a  quarterly  dividend in 2003 of  $0.28125.
     This was our 237th consecutive  quarterly  dividend.  Annualized,  the 2003
     dividend rate is $1.13 per common share  compared to $1.125 in 2003.  Based
     on the 12-month  earnings per share at March 31, 2004, the dividend  payout
     ratio is 85% of net income.  For the full year 2003,  the payout  ratio was
     93% of net income.  On a long-term basis, our goal is to achieve a dividend
     payout  ratio of 60% of net income  accomplished  through  future  earnings
     growth.

     At its April 28,  2004  meeting,  the Board  declared  the  second  quarter
     dividend of $0.2825 per share payable on May 21, 2004, to  stockholders  of
     record  on May 10,  2004.  This  will be the  238th  consecutive  quarterly
     dividend.

Dividend Reinvestment and Stock Purchase Plan
     We have a Dividend  Reinvestment and Stock Purchase Plan (Plan).  Under the
     Plan,  stockholders may reinvest  dividends to purchase  additional Company
     common  stock  without  commission  fees.  The Plan  also  allows  existing
     stockholders  and other  interested  investors to purchase  Company  common
     stock through the transfer agent up to certain  limits.  Our transfer agent
     operates the Plan and purchases shares on the open market to provide shares
     for the Plan.

2004 Financing Plan
     Our 2004  financing  plan  includes  raising  approximately  $40,000,000  -
     $50,000,000 of new capital.  For the current year, issuance of senior notes
     to  institutional  investors,  issuance  of  additional  common  stock or a
     combination thereof will be used to raise new capital. Specific amounts are
     not yet  determined.  If common stock is  utilized,  the common stock issue
     will be  accomplished  with one  issuance  in 2004  pursuant  to the  shelf
     registration.  The timing of the issuance has not been established.  Beyond
     2004,  we intend  to fund  capital  needs  through  a  relatively  balanced
     approach between long-term debt and equity.

Book Value and Stockholders of Record
     Book value per common share was $14.24 at March 31, 2004 compared to $14.44
     at December 31, 2003.

                                       19


     There are approximately 4,500 stockholders of record for our common stock.

Utility Plant Expenditures
     During the three months ended March 31, 2004, capital  expenditures totaled
     $11,612,000; $8,168,000 was from company-funded projects and $3,444,000 was
     from  third  party  funded  projects.   The  2004  company-funded   capital
     expenditure budget is $65,800,000,  but the actual amount may vary from the
     budget  number due to timing of actual  payments  related  to current  year
     projects  and prior year  projects.  We do not control  third-party  funded
     capital expenditures, and therefore we are unable to estimate the amount of
     such projects for 2004.

     At March 31, 2004,  construction work in progress was $20,107,000  compared
     to $13,770,000  at December 31, 2003.  Work in progress  includes  projects
     that are under construction, but not yet complete and in service.

WATER SUPPLY
     Based  on  information  from  water  management   agencies  and  internally
     developed  data,  we believe  that our various  sources of water supply are
     sufficient  to  meet  customer  demand  for  the  remainder  of  the  year.
     Historically,  about half of the water source is purchased  from  wholesale
     suppliers  with the other  half  pumped  from  underground  wells.  A small
     portion is developed through three local surface treatment plants.

     To safeguard our water supply and facilities,  we have heightened  security
     at our facilities and have taken added safety precautions for our employees
     and the water we  deliver  to our  customers.  While we do not make  public
     comments on our security  programs,  we have been in contact with  federal,
     state and local law  enforcement  agencies to coordinate  and improve water
     delivery systems  security.  We have assigned a high priority to completing
     work  necessary to comply with new  Environmental  Protection  Agency (EPA)
     requirements  concerning  security of water  facilities.  In 2002,  federal
     legislation  was  enacted  which  resulted  in new  regulations  concerning
     security of water facilities, including submitting vulnerability assessment
     studies  to the  federal  government.  The  timing of  submission  of these
     studies was based on size of operations. We have submitted the studies that
     are required and plan to complete this program in 2004.

ACQUISITIONS
     See Note 8 of the Condensed Consolidated Financial Statements

ACCOUNTING PRONOUNCEMENTS
     See Note 7 of the Condensed Consolidated Financial Statements

                                       20

Item 3.

QUANTITATIVE AND QUALITATIVE DISCLOSURE ABOUT MARKET RISK
     We do not hold,  trade in or issue  derivative  financial  instruments  and
     therefore are not exposed to risks these  instruments  present.  Our market
     risk to interest  rate  exposure is limited  because the cost of  long-term
     financing and short-term  bank  borrowings,  including  interest  costs, is
     covered in consumer water rates as approved by the  commissions.  We do not
     have  foreign  operations;  therefore,  we do not have a  foreign  currency
     exchange  risk.  Our business is sensitive to commodity  prices and is most
     affected by changes in purchased water and purchased power costs.

     Historically, the CPUC's balancing account or offsetable expense procedures
     allowed for increases in purchased  water and  purchased  power costs to be
     passed on to consumers.  Traditionally, a significant percentage of our net
     income and cash flows comes from California regulated operations; therefore
     the CPUC's actions have a significant  impact on our business.  See Item 2,
     Management's  Discussion and Analysis of Financial Condition and Results of
     Operations--Expense   Balancing  and  Memorandum  Accounts  and  Regulatory
     Matters.


Item 4.

CONTROLS AND PROCEDURES
     (a) Evaluation of Disclosure Controls and Procedures

     We  carried  out an  evaluation,  under  the  supervision  of and  with the
     participation of our management,  including our principal executive officer
     and principal  financial  officer,  of the  effectiveness of the design and
     operation of our  disclosure  controls and  procedures as of the end of the
     period  covered  by this  report,  pursuant  to Rule  13a-15(e)  under  the
     Securities  Exchange Act of 1934.  Based on their review of our  disclosure
     controls and  procedures,  the  principal  executive  officer and principal
     financial   officer  have  concluded  that  our  disclosure   controls  and
     procedures are effective in timely alerting us to material information that
     is required to be included in periodic SEC filings.

     (b) Changes to Internal controls

     There were no changes in our internal control over financial reporting that
     occurred during our last fiscal quarter that have materially  affected,  or
     are reasonably likely to materially affect, such controls.


                                       21

PART II       OTHER INFORMATION

Item 1.

Legal Proceedings

(a)           From time to time,  we have been  involved  in a variety  of legal
              proceedings.  For a complete description, see our annual report on
              Form 10-K for the year ended December 31, 2003. During the quarter
              ended March 31,  2004,  there were no material  developments  with
              respect to previously  disclosed  existing  proceedings and no new
              material proceedings not previously disclosed.


Item 4.

Submission of Matters to a Vote of Security Holders

(a)           The annual  meeting of  stockholders  of California  Water Service
              Group was held on April 28, 2004 at the headquarters office in San
              Jose,  California.  As proposed in the 2004 Proxy  Statement,  the
              election of  directors  and  confirmation  of KPMG LLP to serve as
              independent auditors for 2004 were approved by stockholders at the
              meeting.

(b)           At the annual stockholders  meeting, a Board of Directors to serve
              for the ensuing year was elected.  The  following  directors  were
              elected as nominated:

                      Douglas M. Brown                     Robert W. Foy

                      Edward D. Harris, Jr. M.D.           Richard P. Magnuson

                      Linda R. Meier                       Peter C. Nelson

                      George A. Vera                       David N. Kennedy

                      Bonnie G. Hill

(c)           Two  proposals  were  voted on at the  meeting:  (1)  election  of
              directors  for  the  ensuing  year,  and (2)  ratification  of the
              selection of KPMG LLP as independent auditors for 2004.


                                       22


(1)           Tabulation of the votes for the election of directors was:

                                                      For              Withheld
                                                      ---              --------
              Douglas M. Brown                     15,901,992          110,031
              Robert W. Foy                        15,970,944          110,031
              Edward D. Harris, Jr. M.D            15,964,758          110,031
              Bonnie G. Hill                       15,971,429          110,031
              David N. Kennedy                     15,962,426          110,031
              Richard P. Magnuson                  15,920,085          110,031
              Linda R. Meier                       15,917,719          110,031
              Peter C. Nelson                      15,962,495          110,031
              George A. Vera                       15,918,317          110,031

(2)           The stockholders  ratified the Audit Committee's selection of KPMG
              LLP  to  serve  as  independent  auditors  for  2004.  There  were
              15,877,038 votes in favor, 144,662 against and 90,624 abstentions.


Item 6.

EXHIBITS AND REPORTS ON FORM 8-K

(a)      Exhibits required to be filed by Item 601 of Regulation S-K.

         The exhibit list required by this Item is incorporated by reference to
         the Exhibit Index attached to this report.

(b)      Reports on Form 8-K

         On January 29, 2004, we furnished a Current Report on Form 8-K pursuant
         to Item 12, "Results of Operations and Financial  Condition," attaching
         our press  release  dated  January 28, 2004  announcing  our results of
         operations  for the fourth quarter and year ended December 31, 2003. On
         April 29, 2004,  we furnished a Current  Report on Form 8-K pursuant to
         Item 12, "Results of Operations and Financial Condition," attaching our
         press release dated April 28, 2004 announcing our results for the first
         quarter of 2004.

                                       23

                                   SIGNATURES

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


                         CALIFORNIA WATER SERVICE GROUP
                         ------------------------------
                                   Registrant


May 7, 2004


             By:              /s/ RICHARD D. NYE
                     ----------------------------------------
                                  Richard D. Nye
                     Vice President, Chief Financial Officer
                                  and Treasurer


                                       24


                                  Exhibit Index

   Exhibit                 Description


   31.1                    Chief Executive Officer certification of financial
                           statements pursuant to Section 302 of the Sarbanes-
                           Oxley Act of 2002

   31.2                    Chief Financial Officer certification of financial
                           statements pursuant to Section 302 of the Sarbanes-
                           Oxley Act of 2002

   32                      Chief Executive Officer and Chief Financial Officer
                           Certification pursuant to 18 U.S.C. Section 1350, as
                           adopted pursuant to Section 906 of the Sarbanes-
                           Oxley Act of 2002.


                                       25