UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 10-K

     [X]  ANNUAL  REPORT  PURSUANT  TO  SECTION  13 OR 15(d)  OF THE  SECURITIES
          EXCHANGE ACT OF 1934

     For the fiscal year ended December 31, 2005

                                       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 No. 1-13883

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

              Delaware                                  77-0448994
              --------                                  ----------
    (State of Incorporation)             (I.R.S. Employer Identification No.)

  1720 North First Street, San Jose, California                95112
  ---------------------------------------------                -----
    (Address of Principal Executive Offices)                (Zip Code)

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

           Securities registered pursuant to Section 12(b) of the Act:

     Title of Each Class:            Name of Each Exchange on Which Registered:
     --------------------            ------------------------------------------
  Common Stock, $0.01 Par Value             New York Stock Exchange

             Preferred Share Purchase Rights New York Stock Exchange

           Securities registered pursuant to Section 12(g) of the Act:
                                      None
                                (Title of Class)

Indicate by check mark if the  Registrant is a well-known  seasoned  issuer,  as
defined in Rule 405 of the Securities Act. Yes ___ No _X_

Indicate  by  check  mark if the  registrant  is not  required  to file  reports
pursuant to Section 13 of Section 15(d) of the Act. Yes ___ No _X_

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 check mark if disclosure of delinquent  filers  pursuant to Item 405
of Regulation  S-K is not contained  herein,  and will not be contained,  to the
best of Registrant's  knowledge,  in definitive proxy or information  statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. [ ]

                                       1

Indicate by check mark whether the registrant is a large  accelerated  filer, an
accelerated  filer, or a non- accelerated  filer. See definition of "accelerated
filer and large  accelerated  filer" in Rule 12b-2 of the Exchange  Act.  (Check
one):

Large accelerated filer [ ] Accelerated filer [X] Non-accelerated filer [ ].


Indicate by check mark whether the  registrant is a shell company (as defined in
Rule 12b-2 of the Act). Yes ___ No _X_

The  aggregate  market value of the common stock held by  non-affiliates  of the
Registrant  was $646.7  million on June 30, 2005,  the last  business day of the
registrant's  most recently  completed  second fiscal quarter.  The valuation is
based on the closing price of the registrant's common stock as traded on the New
York Stock Exchange.

Common stock outstanding at March 6, 2006, - 18,405,138 shares.

                                       2

                                  EXHIBIT INDEX

                       DOCUMENTS INCORPORATED BY REFERENCE

Designated  portions  of  Registrant's  Annual  Report to  Stockholders  for the
calendar year ended December 31, 2005,  (2005 Annual Report) are incorporated by
reference in Part I (Item 1 and 2) and Part II (Items 5, 6, 7, 7A, 8 and 9A).

Designated  portions  of the  Registrant's  Proxy  Statement  (Proxy  Statement)
relating  to the  2006  annual  meeting  of  stockholders  are  incorporated  by
reference in Part III (Items 10, 11, 12 and 14).

                                       3
<Page>


                           TABLE OF CONTENTS
                                                                          Page
PART I
  Item  1.    Business..............................................       6
              Forward-Looking Statements............................       6
              General Development of Business.......................       6
              Financial Information about
                  Industry Segments.................................       8
              Narrative Description of Business.....................       8
              Geographical Service Areas and
                  Number of Customers at Year-end...................       8
              Rates and Regulation..................................      10
              Water Supply..........................................      11
              Non-regulated Operations..............................      14
              Utility Plant Construction ...........................      15
              Sale of Surplus Real Properties.......................      15
              California Energy Situation...........................      15
              Security at Company Facilities........................      15
              Quality of Water Supplies.............................      16
              Competition and Condemnation..........................      16
              Environmental Matters ................................      16
              Human Resources.......................................      17
              Financial Information about Foreign and
                  Domestic Operations and Export Sales..............      17

  Item  1A    Risk Factors .........................................      17

  Item  1B    Unresolved Staff Comments ............................      20

  Item  2.    Properties ...........................................      21

  Item  3.    Legal Proceedings.....................................      21

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

              Executive Officers of the Registrant..................      22

PART II

  Item  5.    Market for Registrant's Common Equity,
                  Related Stockholder Matters and Issuer
                  Purchases of Equity Securities....................      25

  Item  6.    Selected Financial Data...............................      25

  Item  7.    Management's Discussion and Analysis of
                  Financial Condition and Results of
                  Operations........................................      25

  Item 7A.     Quantitative and Qualitative Disclosures About
                   Market Risk.......................................     25

  Item  8.    Financial Statements and Supplementary Data...........      25


                                       4



  Item  9.    Changes in and Disagreements with Accountants on
                    Accounting and Financial Disclosure.............      25

  Item 9A.    Controls and Procedures...............................      26

  Item 9B.    Other Information.....................................      26


PART III

  Item 10.    Directors and Executive Officers of the Registrant....      26

  Item 11.    Executive Compensation................................      26

  Item 12.    Security Ownership of Certain Beneficial
                    Owners and Management ..........................      26

  Item 13.    Certain Relationships and Related Transactions........      26

  Item 14.    Principal Accountant Fees and Services................      27

PART IV

  Item 15.    Exhibits, Financial Statement Schedules...............      27

Signatures..........................................................      28

Exhibit Index.......................................................      30

                                       5

                                     PART I

Item 1.   Business.

Forward-Looking Statements
- --------------------------

This annual 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,
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,  including  decisions on
proper disposition of property;  changes in regulatory commissions' policies and
procedures;  the timeliness of regulatory  commissions'  actions concerning rate
relief;  new legislation;  changes in accounting  valuations and estimates;  the
ability to satisfy  requirements  related  to the  Sarbanes-Oxley  Act and other
regulations on internal  controls;  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 the 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 current or future debt that could increase  financing costs or affect
the ability to borrow, make payments on debt, or pay dividends;  and other risks
and unforeseen events. When considering  forward-looking  statements, the reader
should keep in mind the cautionary  statements  included in this paragraph.  The
Company  assumes no  obligation  to provide  public  updates on  forward-looking
statements.

a.   General Development of Business
     -------------------------------

California  Water Service Group (the Company) is a holding company  incorporated
in Delaware with five operating  subsidiaries:  California Water Service Company
(Cal Water), CWS Utility Services (Utility  Services),  New Mexico Water Service
Company (New Mexico Water), Washington Water Service Company (Washington Water),
and Hawaii Water Service  Company,  Inc.  (Hawaii Water).  Cal Water, New Mexico
Water,  Washington Water, and Hawaii Water are regulated public  utilities.  The
regulated  utility entities also provide some  non-regulated  services.  Utility
Services   provides    non-regulated   services   to   private   companies   and
municipalities.  Cal Water was the originating  company and began  operations in
1926. The other entities were incorporated within the last 10 years.

California  water operations are conducted by the Cal Water and Utility Services
entities,  which  provide  service  to  approximately  456,700  customers  in 75
California communities through 26 separate districts.  Of these 26 districts, 24
districts are regulated  water  systems,  which are subject to regulation by the
California Public Utilities  Commission (CPUC). The other 2 districts,  the City
of Hawthorne and the City of Commerce,  are governed  through  their  respective
city councils and are considered  non-regulated  because they are outside of the
CPUC's  jurisdiction.  Their activities are reflected in the Company's operating
revenue and operating  costs,  as the risks and rewards of these  operations are
similar to the  Company's  regulated  activities.  California  water  operations
account for 95% of the total customers and 96% of the total operating revenue of
the Company.

Washington  Water  provides  domestic  water service to 15,311  customers in the
Tacoma and Olympia areas. Washington Water's utility operations are regulated by
the  Washington  Utilities  and  Transportation  Commission.   Washington  Water
accounts for 3% of the total customers and 2% of the total operating  revenue of
the Company.

                                       6


New Mexico Water provides service to 6,480 water and wastewater customers in the
Belen,  Los  Lunas  and  Elephant  Butte  areas  in New  Mexico.  Its  regulated
operations are subject to the  jurisdiction of the New Mexico Public  Regulation
Commission.  New Mexico Water  accounts for 1% of the total  customers and 1% of
the total operating revenue of the Company.

Hawaii  Water  provides  water  service to 537  customers on the island of Maui,
including  several  large  resorts  and  condominium  complexes.  Its  regulated
operations  are  subject  to the  jurisdiction  of the Hawaii  Public  Utilities
Commission. Hawaii Water accounts for less than 1% of the total customers and 1%
of the total operating revenue of the Company.

Other  non-regulated  activities  consist  primarily of operating water systems,
which are owned by other entities; providing meter reading and billing services;
leasing  communication  antenna  sites on the  Company's  properties;  operating
recycled water systems; providing brokerage services for water rights; providing
lab  services for water  quality  testing;  and selling  surplus  property.  The
results of these  activities are reported below  operating  profit on the income
statement and therefore the revenue is not included in operating revenue. Due to
the variety of services  provided and activities  being outside of the Company's
core  business,  the number of customers is not tracked for these  non-regulated
activities  except customers for the City of Hawthorne and the City of Commerce.
Non-regulated  activities,  excluding  gains  on sale of  non-utility  property,
comprised 6% of the Company's total net income in 2005.

The state regulatory entities governing the Company's  regulated  operations are
referred  to as the  Commissions  in  this  report.  Rates  and  operations  for
regulated  customers are subject to the  jurisdiction of the respective  state's
regulatory  commission.  The Commissions require that water and wastewater rates
for each regulated  district be  independently  determined.  The Commissions are
expected to authorize rates sufficient to recover normal operating  expenses and
allow the  utility to earn a fair and  reasonable  return on  invested  capital.
Rates  for  the  City of  Hawthorne  and  City of  Commerce  water  systems  are
established  in  accordance  with  operating   agreements  and  are  subject  to
ratification  by the  respective  city  councils.  Fees for other  non-regulated
activities are based on contracts negotiated between the parties.

The Company's mailing address and contact information is:
    California Water Service Group
    1720 North First Street
    San Jose, California 95112-4598
    telephone number: 408-367-8200
    www.calwatergroup.com

Annual reports on Form 10-K,  quarterly reports on Form 10-Q, current reports on
Form 8-K and  amendments to these reports are available  free of charge  through
the Company's website. The reports are available on the Company's website on the
same day they appear on the SEC's website.

During the year ended December 31, 2005,  there were no  significant  changes in
the kind of  products  produced or  services  rendered or those  provided by the
Company's operating subsidiaries, or in the markets or methods of distribution.

                                       7


b.   Financial Information about Industry Segments
     ---------------------------------------------

The  Company  operates  primarily  in  one  business  segment,  the  supply  and
distribution of water and providing water-related utility services.

c.   Narrative Description of Business
     ---------------------------------

The business is conducted through the Company's operating subsidiaries. The bulk
of the  business  consists  of the  production,  purchase,  storage,  treatment,
testing,  distribution  and sale of water for domestic,  industrial,  public and
irrigation  uses,  and for fire  protection.  Also  provided  are  non-regulated
water-related  services under agreements with  municipalities  and other private
companies.  The  non-regulated  services  include full water  system  operation,
billing and meter reading  services.  Non-regulated  operations also include the
lease of communication antenna sites, lab services,  water rights brokerage, and
our Extended Service Protection program.  Earnings may be significantly affected
by the sale of surplus real properties if and when they occur.

Operating results from the water business fluctuate  according to the demand for
water,  which  is  often  influenced  by  seasonal  conditions,  such as  summer
temperatures or the amount and timing of precipitation in the Company's  service
areas.  Revenue,  expenses  and income are  affected by changes in water  sales.
Expenses for purchased  water,  purchased  power and pump taxes will vary due to
changes in water  sales.  The  majority  of other  costs,  such as  payroll  and
benefits,  depreciation,  interest on long-term debt and property taxes are more
predictable,  remain  fairly  constant,  and are not  significantly  impacted by
variations in the amount of water sold. As a result, earnings are highest in the
high use, warm weather summer months when rainfall is lower.  Earnings are lower
in the cool  winter  months  when most  rainfall  takes  place in the  Company's
service territories.

The Company distributes water in accordance with accepted water utility methods.
Where  applicable,  the Company holds  franchises  and permits in the cities and
communities  where it operates.  The franchises and permits allow the Company to
operate  and  maintain  facilities  in public  streets  and  right-  of-ways  as
necessary.

The  Company  operates  the City of  Hawthorne  and the City of  Commerce  water
systems under lease  agreements.  In accordance with the lease  agreements,  the
Company  receives all revenues from operating the systems and is responsible for
paying the  operating  costs.  Under other  contract  arrangements,  the Company
operates  municipally  owned water systems,  privately owned water systems,  and
recycled water  distribution  systems,  but is not responsible for all operating
costs. These contracts are  fee-per-service,  fixed-fee or cost-plus  contracts.
The Company also  provides  billing and other  customer  services to a number of
municipalities.

The Company intends to continue exploring  opportunities to expand its regulated
and  non-regulated  businesses in the western United States.  The  opportunities
could include system  acquisitions,  lease  arrangements  similar to the City of
Hawthorne  contract,  full service system operation and maintenance  agreements,
meter reading, billing contracts and other utility-related services.  Management
believes that a holding company structure  facilitates  providing  non-regulated
utility services, which are not subject to Commission jurisdiction.

Geographical  Service  Areas and Number of Customers  at Year-end
- -----------------------------------------------------------------
The  Company's  principal  markets are users of water within its service  areas.
Most of the geographical service areas or districts are regulated.  In addition,
the City of Hawthorne and City of Commerce are included due to  similarities  in
structure and risk of operations.  The approximate number of customers served in
each district is as follows:

                                       8


Regulated  Customers,  City of  Hawthorne  and  City of  Commerce  Customers  at
December 31,



                                                                                      2005             2004
                                                                                  -----------      -----------
                                                                                                 
SAN FRANCISCO BAY AREA
  Mid-Peninsula (serving San Mateo and San Carlos)                                    36,100           36,100
  South San Francisco (including Colma and Broadmoor)                                 16,800           16,700
  Bear Gulch (serving portions of Menlo Park, Atherton,
      Woodside and Portola Valley)                                                    18,000           17,700
  Los Altos (including portions of Cupertino, Los Altos Hills,
      Mountain View and Sunnyvale)                                                    18,500           18,500
  Livermore                                                                           18,100           17,900
                                                                                  -----------      -----------
                                                                                     107,500          106,900
                                                                                  -----------      -----------
SACRAMENTO VALLEY
  Chico (including Hamilton City)                                                     26,400           25,900
  Oroville                                                                             3,600            3,500
  Marysville                                                                           3,800            3,800
  Dixon                                                                                2,900            2,900
  Willows                                                                              2,300            2,300
  Redwood Valley (Lucerne, Duncans Mills, Guerneville, Dillon Beach, Noel
  Heights & portions of Santa Rosa)                                                    2,000            2,000
                                                                                  -----------      -----------
                                                                                      41,000           40,400
                                                                                  -----------      -----------
SALINAS VALLEY
  Salinas                                                                             27,800           27,800
  King City                                                                            2,400            2,300
                                                                                  -----------      -----------
                                                                                      30,200           30,100
                                                                                  -----------      -----------
SAN JOAQUIN VALLEY
  Bakersfield                                                                         63,600           62,400
  Stockton                                                                            42,300           41,800
  Visalia                                                                             35,800           34,500
  Selma                                                                                6,000            5,800
  Kern River Valley                                                                    4,300            4,200
  Antelope Valley (Fremont Valley, Lake Hughes, Lancaster & Leona Valley)              1,400            1,400
                                                                                  -----------      -----------
                                                                                     153,400          150,100
                                                                                  -----------      -----------
LOS ANGELES AREA
  East Los Angeles (including portions of the City of Commerce)                       27,800           27,700
  Hermosa-Redondo (serving Hermosa Beach, Redondo Beach
      and a portion of Torrance)                                                      26,100           26,000
  Dominguez (Carson and portions of Compton, Harbor City,
      Long Beach, Los Angeles and Torrance)                                           33,600           33,500
  Palos Verdes (including Palos Verdes Estates, Rancho Palos Verdes,
      Rolling Hills Estates and Rolling Hills)                                        24,000           24,000
  Westlake (a portion of Thousand Oaks)                                                7,000            7,000
  Hawthorne (leased municipal system)                                                  6,100            6,100
                                                                                  -----------      -----------
                                                                                     124,600          124,300
                                                                                  -----------      -----------
CALIFORNIA TOTAL                                                                     456,700          451,800

HAWAII                                                                                   500              500
NEW MEXICO                                                                             6,500            5,800
WASHINGTON                                                                            15,300           15,000
                                                                                  -----------      -----------
COMPANY TOTAL                                                                        479,000          473,100
                                                                                  ===========      ===========


                                       9

Rates and Regulation
- --------------------

The Company's  water  utility  rates and service for the regulated  business are
subject  to  the   jurisdiction  of  the  state  regulatory   commissions.   The
Commissions'  decisions and the timing of those decisions can have a significant
impact on the operations and earnings.

Since  the  Company's  24  California-regulated   operating  districts  are  not
physically integrated, rates are set independently for each district as required
by the CPUC. General office (headquarters) expenses and capital expenditures are
considered separately and allocated ratably to the operating districts.

General and Step Rate Increases
- -------------------------------

General rate case (GRC)  applications in California address district and general
office operating costs and capital requirements for a forward-looking three-year
period. GRC decisions  typically authorize an immediate rate increase and annual
step rate increases for the three-year  cycle. Step rate increases are generally
effective at the start of each calendar  year,  and are designed to maintain the
return on equity (ROE) authorized in the initial  decision in succeeding  years.
Effective  January  1,  2003,  Cal  Water  is  required  to file a GRC for  each
operating  district every three years.  Previously,  Cal Water's GRC preliminary
applications were submitted in July of each year. Effective in 2004, preliminary
applications are scheduled for submission in May and each year thereafter.

According to the CPUC's processing schedule, a final decision should be expected
about 12 months after the filings are  accepted by the CPUC.  The backlog of Cal
Water's  overdue  filings has been cleared and there are no pending filings that
have gone  beyond  the  expected  decision  date.  In 2004 and  2005,  Cal Water
received GRC decisions on a timely basis.  Cal Water expects  future  filings to
receive decisions on the CPUC's published processing time line. If decisions are
delayed in the future,  legislation enacted in 2003 gives the Company protection
by  establishing  an  effective  date when the  decision  should have been made,
allowing  interim rates to be charged and retroactive  adjustments once the CPUC
renders a decision.

Because districts are on different  three-year GRC rate case cycles,  the number
of customers affected by GRC filings varies from year to year.

Water rates for Washington  Water and New Mexico Water regulated  operations are
set based on historic  12-month data.  Applications  are filed on an "as needed"
basis and can be submitted annually.  Water rates for Hawaii Water are set based
on a combination  of historical  base and  forward-looking  methodology  and are
allowed to be filed  annually.  In these  states,  regulatory  procedures do not
provide for step rate increases or offset increases,  (see "Offsetable  Expenses
and Balancing  Accounts"  below) except for Hawaii which allows  immediate  rate
adjustments to changes in purchased power rates.

Offsetable Expenses and Balancing Accounts
- ------------------------------------------

The Company records costs for purchased water, purchased power and pump taxes as
incurred.  Expenses for these categories above or below levels included in prior
GRC decisions are tracked in off-line expense balancing or memorandum  accounts.
The cost  differences  are  referred to as  offsetable  expenses.  When the CPUC
authorizes  a rate change to recover the costs  tracked in expense  balancing or
memorandum  accounts,  the rate change is referred to as an offset rate  change.
The Company does not record revenue or refunds related to the balancing accounts
until authorized by the CPUC, and then only as the authorized rates are included
in customers' monthly billings.  Currently, recovery of balancing and memorandum
accounts  is  subject to a  downward  adjustment  only based on a review of each
district's  earnings for the past calendar year. If the recorded  return on rate
base exceeds the rate  authorized by the  Commission,  recovery of the balancing
account  balance  is  adjusted  downward  by the  amount of  earnings  above the
authorized return.

See Item 7,  "Management's  Discussion  and Analysis of Financial  Condition and
Results of Operations--  RATES AND REGULATIONS"  section for more information on
rates and regulation.

                                       10


Water Supply
- ------------

Cal Water obtains its water supply from wells, surface runoff or diversion,  and
by purchase from public  agencies and other wholesale  suppliers.  The Company's
water supply has been adequate to meet customer demand;  however, during periods
of  drought  some  districts  have   experienced   mandatory  water   rationing.
California's rainy season usually begins in November and continues through March
with the most rain typically falling in December,  January and February.  During
winter months,  reservoirs and underground aquifers are replenished by rainfall.
Snow  accumulated  in the  mountains  provides an  additional  water source when
spring and summer temperatures melt the snowpack,  producing runoff into streams
and reservoirs, and also replenishing underground aquifers.

Washington  and Hawaii  receive rain in all seasons  with the  majority  falling
during winter months.  Washington Water and Hawaii Water draw all of their water
supply by pumping from wells.

New Mexico Water's rainfall  normally occurs in all seasons,  but is heaviest in
the summer monsoon  season.  New Mexico Water pumps all of its water supply from
wells based on its water rights.

The Company's  water  business is seasonal in nature and weather  conditions can
have a pronounced effect on customer usage and thus,  impact operating  revenues
and net income.  Customer  demand for water generally is lower during the cooler
and rainy,  winter  months.  Demand  increases in the spring when warmer weather
returns and the rains end, and  customers  use more water for outdoor  purposes,
such as landscape irrigation.  Warm temperatures during the generally dry summer
months  result in  increased  demand.  Water usage  declines  during the fall as
temperatures decrease and the rainy season begins.

During years in which  precipitation  is especially  heavy or extends beyond the
spring into the early summer,  customer demand can decrease from historic normal
levels,  generally due to reduced outdoor water usage.  Likewise, an early start
to the rainy  season  during the fall can cause a decline in customer  usage and
have a negative  impact on  revenue.  When summer  temperatures  are cooler than
normal, water usage is generally lower and can result in lower revenue and lower
earnings. A warmer than normal summer can result in higher customer usage and an
increase in revenue and earnings.

Drought can have an impact on the  business.  When rainfall is below average for
consecutive  years,  drought conditions can develop and certain customers may be
required to reduce consumption to preserve available supply. As an example, from
1987 to 1993,  California  experienced a six-year period when rainfall was below
historic  average.  During that period,  some districts  issued  water-rationing
requirements to their customers.  In certain districts,  penalties were assessed
on customers  who exceeded  monthly  allotments,  which was approved by the CPUC
after local  governments  enacted  ordinances  for drought.  During past drought
periods,  the CPUC has allowed  modifications to Cal Water's  customer  billings
that  provided a means to recover a portion of revenue  that was deemed lost due
to conservation measures,  although there are no assurances the CPUC would do so
in future droughts.

As noted above, Washington Water, New Mexico Water and Hawaii Water obtain their
entire water supply from wells.  Historically,  about half of Cal Water's  water
supply is purchased from wholesale suppliers with the balance pumped from wells.
During 2005,  approximately 46 percent of the Cal Water supply was obtained from
wells,  50 percent was  purchased  from  wholesale  suppliers  and 4 percent was
obtained from surface  supplies.  Well water is generally less expensive and Cal
Water  strives to maximize the use of its well sources in districts  where there
is an option between well or purchased supply sources.

The Company has five California water treatment plants in the Bakersfield,  Bear
Gulch,  Kernville,  Oroville and Redwood Valley  districts.  A new plant was put
into service during 2003 in  Bakersfield,  with a capacity of 20 million gallons
per day.  Water for  operation of the plant is drawn from the Kern River under a
long-term  contract  with  the  City of  Bakersfield.  The  smaller  Bakersfield
treatment  plant  was  removed  from  service  when the new plant  became  fully
functional. The other four plants have a capacity of 13 million gallons per day.

                                       11


During  2005,  the  Company  delivered  132  billion  gallons  of  water  to its
customers,  down 3% from the 139 billion  gallons  delivered  in 2004.  The 2005
average daily water production was 356 million gallons, while the maximum single
day production  was 471 million  gallons.  By  comparison,  in 2004, the average
daily  water  production  was 380 million  gallons  and the  maximum  single day
production was 635 million gallons.

The following  table shows the quantity of water purchased and the percentage of
purchased water to total water production in each California  operating district
that purchased  water in 2005. All other  districts  receive 100% of their water
supply from wells.



                                  (MG)
                                 Water
                               Production      Supply
District                       Purchased     Purchased    Source of Purchased Supply
- --------                       ---------     ---------    --------------------------
                                                 
SAN FRANCISCO BAY AREA
    Mid-Peninsula               5,948          100%       San Francisco Water Department
    South San Francisco         3,140          100%       San Francisco Water Department
    Bear Gulch                  3,830           87%       San Francisco Water Department
    Los Altos                   3,126           65%       Santa Clara Valley Water District
    Livermore                   2,719           73%       Alameda County Flood Control and Water
                                                          Conservation District

SACRAMENTO VALLEY
    Oroville                      937           86%       Pacific Gas and Electric Co. and County
                                                          of Butte
    Redwood Valley                153           77%       County of Lake

SAN JOAQUIN VALLEY
    Antelope/Kern                 295           34%       Antelope Valley-East Kern Water Agency
                                                          and City of Bakersfield
    Bakersfield                 5,792           22%       Kern County Water Agency and City of
                                                          Bakersfield
    Stockton                    6,371           61%       Stockton East Water District

LOS ANGELES AREA
    East Los Angeles            4,579           70%      Central Basin Municipal Water District
    Dominguez                  11,738           89%      West Basin Municipal Water District
    City of Commerce              196           24%      Central Basin Municipal Water District
    Hawthorne                   1,480           90%      West Basin Municipal Water District
    Hermosa-Redondo             4,036           85%      West Basin Municipal Water District
    Palos Verdes                6,682          100%      West Basin Municipal Water District
    Westlake                    3,006          100%      Calleguas Municipal Water District


MG = million gallons

The Bear Gulch  district  obtains a portion  of its water  supply  from  surface
runoff from the local watershed.  In the Oroville and Redwood Valley  districts,
the water purchased is from a surface supply.  The surface sources are processed
through the water treatment  plants before being  delivered to the  distribution
system.  In the  Bakersfield  and  Kern  River  Valley  districts,  the  Company
purchases  surface supply then processes the water through its treatment plants.
In addition,  the Bakersfield district purchases treated water as a component of
its water supply.

The Chico,  Marysville,  Dixon, and Willows districts in the Sacramento  Valley,
the Salinas and King City  districts  in the Salinas  Valley,  and the Selma and
Visalia  districts in the San Joaquin  Valley  obtain  their entire  supply from
wells.

                                       12


In the Salinas district,  which solely depends upon ground water,  several wells
were  taken out of  service  in the last 24 months  primarily  due to poor water
quality.  The Company has  installed  treatment  systems on some of these wells.
Management  believes  that water supply  issues in the Salinas  district will be
adequately resolved in 2006 and beyond.

Purchases for the Los Altos, Livermore,  Oroville, Redwood Valley, Stockton, and
Bakersfield  districts are pursuant to long-term  contracts  expiring on various
dates after 2011.

The  water   supplies   purchased   for  the   Dominguez,   East  Los   Angeles,
Hermosa-Redondo,  Palos Verdes,  and Westlake  districts,  the City of Hawthorne
system, and the City of Commerce system are provided by public agencies pursuant
to a statutory  obligation  of continued  non-preferential  service to purveyors
within the agencies' boundaries.

Purchases for the South San Francisco,  Mid-Peninsula,  and Bear Gulch districts
are in  accordance  with  long-term  contracts  with  the  San  Francisco  Water
Department (SFWD) expiring on June 30, 2009.

Management  anticipates that the Company will be able to renew each of the water
supply  contracts as they  expire.  The price of  wholesale  water  purchases is
subject to pricing changes  imposed by the various  wholesale  suppliers.  Price
changes are generally beyond the Company's control.  Management expects that the
Company will be allowed to recover the wholesale water suppliers' rate increases
in  customers'  future  rates,  although  recovery is subject to approval by the
CPUC.

Shown below are wholesaler  price rates and increases  that became  effective in
2005, and estimated wholesaler price rates changes for 2006.


                                   2005                                      2006
                    Effective     Percent                     Effective    Percent
     District         Month       Change      Unit Cost         Month       Change       Unit Cost
     --------         -----       ------      ---------         -----       ------       ---------
                                                                       
  Antelope             July        0.0%        $220/af           July        8.6%         $239/af
  Bakersfield *        July        7.7%         136/af           July        7.4%          146/af
  Bear Gulch           July        4.4%       1.02/ccf           July        0.0%        1.02/ccf
  City of Commerce     Jan         2.9%         488/af           Jan         2.0%          498/af
  Dominguez            Jan         2.9%         536/af           Jan.        1.7%          545/af
  East Los Angeles     July        6.8%         488/af           July        2.0%          498/af
  Hawthorne            Jan         2.9%         536/af           Jan.        1.7%          545/af
  Hermosa-Redondo      Jan         2.9%         536/af           Jan.        1.7%          545/af
  Livermore            Jan.        0.0%       1.29/ccf           Jan.        5.2%        1.36/ccf
  Los Altos            July        6.1%         510/af           July        2.9%          525/af
  Oroville             Jan         8.4%      69,200/yr           Jan.        8.4%       75,000/yr
  Palos Verdes         Jan         2.9%         536/af           Jan.        1.7%          545/af
  Mid-Peninsula        July        4.4%       1.02/ccf           July        0.0%        1.02/ccf
  Redwood Valley       May         4.0%       46.17/af           May         4.0%        48.00/af
  So. San Francisco    July        4.4%       1.02/ccf           July        0.0%        1.02/ccf
  Stockton             April      23.5%     376,292/mo           April      -2.7%      366,146/mo
  Westlake             Jan.        8.4%         650/af           Jan.        3.8%          675/af


af = acre foot;  ccf = hundred  cubic feet;  yr = fixed annual cost;  mo = fixed
monthly cost * untreated water

See Item 7,  "Management's  Discussion  and Analysis of Financial  Condition and
Results of Operations - WATER SUPPLY" concerning more information on adequacy of
supplies.

The Company works with all local  suppliers and agencies  responsible  for water
supply to insure adequate, long-term supply for each system.

                                       13


Non-regulated Operations
- ------------------------

Non-regulated operations include full service operation and maintenance of water
systems for cities and private  owners,  operation  of recycled  water  systems,
meter reading services,  utility billing services,  laboratory  services,  water
rights brokering, sales of surplus properties,  leases of antenna sites, and our
Extended Service Protection program.

Non-regulated  revenue  received  from  water  system  operations  is  generally
determined on a fee-per-customer basis. With the exception of the agreements for
operation of the City of Hawthorne and City of Commerce water  systems,  revenue
and expenses from non-regulated operations are accounted for in other income and
expense on a pretax basis in the Consolidated  Statements of Income. The Company
reports  revenue and  expenses  for the City of  Hawthorne  and City of Commerce
leases in  operating  revenue  and  operating  expenses  because  the Company is
entitled to retain all customer  billings and is generally  responsible  for all
operating expenses.

The Company  operates  municipally  owned water systems  under  contract for the
various cities.  Washington Water operates  numerous private water systems under
contract  arrangements.  The City of  Hawthorne  lease is a  15-year  lease  and
expires in 2011.  The City of Commerce  lease is a 15-year  lease and expires in
2018. The terms of other operating  agreements range from one-year to three-year
periods with provisions for renewals.

The Company  provides  meter reading and customer  billing  services for several
municipalities in California. The Company also provides sewer and refuse billing
services to several municipalities.

In February 1996,  the Company  entered into an agreement to operate the City of
Hawthorne water system.  The system,  which is located near the  Hermosa-Redondo
district,  serves about half of Hawthorne's  population.  The agreement required
the Company to make an up-front  $6.5 million  lease payment to the city that is
being amortized over the lease term. Additionally, annual lease payments of $0.1
million  are made to the city and indexed to changes in water  rates.  Under the
lease,  the  Company is  responsible  for all  aspects of system  operation  and
capital  improvements,  although  title to the system  and  system  improvements
reside with the city. At the end of the lease, the city is required to reimburse
the Company for the unamortized  value of capital  improvements  made during the
term of the lease. In exchange,  the Company receives all revenue from the water
system, which was $5.8 million and $5.9 million in 2005 and 2004, respectively.

In July 2003, an agreement was negotiated with the City of Commerce to lease and
operate its water system. At this time, the lease has not been formally executed
by the parties.  Both parties are in agreement with  substantially all terms and
are operating as if the agreement was executed.  The lease  requires the Company
to pay $0.8 million per year in monthly  installments and pay $200 per acre-foot
for water usage  exceeding 2,000 acre-feet per year plus a percentage of certain
operational savings that may be realized. Under the lease agreement, the Company
is  responsible  for  all  aspects  of the  system's  operations.  The  city  is
responsible  for  capital  expenditures,  and  title to the  system  and  system
improvements  resides  with the city.  The  Company has risks of  operation  and
collection of amounts billed to customers. The agreement includes a procedure to
request  rate changes for costs  changes  outside of the  Company's  control and
other cost  changes.  In  exchange,  the Company  receives  all revenue from the
system, which totaled $1.7 million for 2005 and $1.8 million for 2004.

The Company leases  antenna sites to  telecommunication  companies,  which place
equipment at various  Company-owned sites.  Individual lease payments range from
$700 to $2,600 per month.  The antennas are used in cellular  phone and personal
communication  applications.  The Company  continues to negotiate new leases for
similar uses.

The Company  provides  laboratory  services to San Jose Water  Company and Great
Oaks  Water  Company  and  for  the  systems  under  operation  and  maintenance
agreements.

In 2005, the Company implemented an Extended Service Protection  program,  which
covers repairs to the customer's water line between the meter and the home.

                                       14



Utility Plant Construction
- --------------------------

The Company has continually extended,  enlarged,  and replaced its facilities as
required  to meet  increasing  demands and to maintain  the water  systems.  The
Company obtains construction  financing using funds from operations,  short-term
bank   borrowings,   long-term   financing,   advances  for   construction   and
contributions in aid of construction that are funded by developers.  The amounts
received from these sources are shown in the section  captioned  "Statements  of
Cash Flows" in the annual report,  which is  incorporated  into this document by
reference.  Advances for  construction  are cash  deposits from  developers  for
construction of water  facilities or water  facilities  deeded from  developers.
These  advances are generally  refundable  without  interest over a period of 40
years by equal annual payments.  Contributions in aid of construction consist of
nonrefundable cash deposits or facilities transferred from developers, primarily
for fire  protection  and  relocation  projects.  The Company cannot control the
amount received from developers. This amount fluctuates from year-to-year as the
level of construction activity carried on by developers varies. This activity is
impacted by the demand for housing, commercial development, and general business
conditions, including interest rates.

See Item 7,  "Management's  Discussion  and Analysis of Financial  Condition and
Results  of  Operations  -  LIQUIDITY  AND  CAPITAL  RESOURCES"  for  additional
information.

Sale of Surplus Real Properties
- -------------------------------

When properties are no longer used and useful for public utility  purposes,  the
Company is no longer  allowed to earn a return on its investment in the property
in the  regulated  business.  The  surplus  property is  transferred  out of the
regulated  operations and some properties have been sold or offered for sale. As
these  sales are  subject to local real estate  market  conditions  and can take
several months or years to close, income from the sale of surplus properties may
or may not be consistent from year-to-year.  The CPUC is currently reviewing the
Company's  handling of these  surplus  properties,  which may  adversely  impact
future  sales,  results  of  operations  and  cash  flows.  See  item 3,  "LEGAL
PROCEEDINGS" for additional information.

California Energy Situation
- ---------------------------

The business uses electrical  power primarily to pump water from its sources and
move it through the distribution  systems. The California energy crisis was well
publicized.  Electricity  rates stabilized  during 2003 and the Company received
credits from the electrical  power  companies.  Electricity  rates were lower in
2004 as  compared  to 2003.  Electrical  power  costs are  described  in Item 7,
"Management's  Discussion  and  Analysis of Financial  Condition  and Results of
Operations - RESULTS OF OPERATIONS."

There is still  uncertainty  about the state's  ability to avoid future  rolling
electric  blackouts,  although the Company did not experience any major electric
blackouts during 2005 or 2004. The Company continues to use power efficiently to
minimize the power expenses  passed on to its customers.  The Company  maintains
backup power  systems to continue  water  service to its  customers if the power
companies'  supplies  are  interrupted.  Many of the  Company's  well  sites are
equipped with emergency electric  generators  designed to produce electricity to
keep the wells  operating  during  power  outages.  Storage  tanks also  provide
customers with water during blackout periods.

Security at Company Facilities
- ------------------------------

Due to terrorist  and other risks,  the Company has  heightened  security at its
facilities  over the past few years and has taken added  precautions  to protect
its employees and the water delivered to customers. In 2002, federal legislation
was  enacted  that  resulted  in new  regulations  concerning  security of water
facilities, including submitting vulnerability assessment studies to the federal
government.   The  Company  has  complied   with  EPA   regulations   concerning
vulnerability  assessments  and has  made  filings  to the EPA as  required.  In
addition,  communication  plans  have  been  developed  as a  component  of  the
Company's  procedures.  While the Company  does not make public  comments on its
security  programs,  the Company has been in contact with  federal,  state,  and
local law enforcement agencies to coordinate and improve water delivery systems'
security.

                                       15

Quality of Water Supplies
- -------------------------

The  Company  operating  practices  are  designed  to produce  potable  water in
accordance   with  accepted   water  utility   practices.   Water  entering  the
distribution  systems from surface sources is treated in compliance with federal
and state Safe  Drinking  Water Acts (SWDA)  standards.  Most well  supplies are
chlorinated or  chloraminated  for  disinfection.  Water samples from each water
system are analyzed on a regular,  scheduled basis in compliance with regulatory
requirements. The Company operates a state-certified water quality laboratory at
the San Jose General  Office that  provides  testing for most of its  California
operations.   Certain  tests  in  California  are  contracted  with  independent
certified  labs  qualified  under  the  Environmental  Laboratory  Accreditation
Program. Local independent state certified labs provide water sample testing for
the Washington, New Mexico and Hawaii operations.

In recent years,  federal and state water quality  regulations have continued to
increase water testing requirements. The SDWA continues to be amended to reflect
new public health concerns.  The Company monitors water quality standard changes
and upgrades its treatment  capabilities to maintain compliance with the various
regulations.

Competition and Condemnation
- ----------------------------

The  Company's  principal  operations  are  regulated by the  Commission of each
state.  Under state laws, no privately  owned public  utility may compete within
any service  territory that the Company already serves without first obtaining a
certificate of public convenience and necessity from the Commission. Issuance of
such a certificate would only be made upon finding that the Company's service is
deficient.  To management's  knowledge,  no application to provide service to an
area served by the Company has been made.

State law provides that whenever a public agency constructs facilities to extend
a utility system into the service area of a privately owned public utility, such
an act  constitutes  the taking of property  and requires  reimbursement  to the
utility for its loss. State statutes allow  municipalities,  water districts and
other  public  agencies to own and operate  water  systems.  These  agencies are
empowered  to condemn  properties  already  operated by  privately  owned public
utilities.  The agencies are also authorized to issue bonds,  including  revenue
bonds, for the purpose of acquiring or constructing water systems. However, if a
public agency were to acquire  utility  property by eminent domain  action,  the
utility would be entitled to just  compensation  for its loss.  To  management's
knowledge,   no  municipality,   water  district,  or  other  public  agency  is
contemplating  or has any  action  pending  to  acquire  or  condemn  any of the
Company's systems.

In recent years,  consolidation  within the water  industry has  accelerated.  A
number of publicly  traded  water  companies  have been  acquired or merged into
larger domestic  companies.  Several  acquisitions of publicly traded  companies
have also been completed by much larger foreign  companies.  The Company intends
to continue the pursuit of  opportunities  to expand its business in the western
United States.

Environmental Matters
- ---------------------

The  Company's  operations  are subject to  environmental  regulation by various
governmental  authorities.  Environmental affairs programs have been designed to
provide compliance with water discharge regulations, underground and aboveground
fuel storage tank regulations,  hazardous materials management plans,  hazardous
waste regulations,  air quality permitting  requirements,  wastewater  discharge
limitations and employee safety issues related to hazardous materials. Also, the
Company actively investigates alternative technologies for meeting environmental
regulations  and  continues  the  traditional  practices of meeting  environment
regulations.

                                       16


Human Resources
- ---------------

At year-end  2005,  the Company had 840  employees,  including 41 at  Washington
Water, 15 at New Mexico Water and 7 at Hawaii Water. The Company had 837 and 813
employees in 2004 and 2003,  respectively.  In California,  most non-supervisory
employees are  represented  by the Utility  Workers  Union of America,  AFL-CIO,
except certain  engineering and laboratory  employees who are represented by the
International Federation of Professional and Technical Engineers, AFL-CIO.

At December  31,  2005,  there were 566 union  employees.  In December  2005 and
January  2006,  the Company  negotiated  two-year  agreements  with both unions.
Improvements in tuition reimbursement,  increase in 401k employee contributions,
and  wage  increases  were  part of the  agreement.  Wage  increases  under  the
agreements are 3.5% for 2006. Wages for 2007 will be negotiated in October 2006.
The  Company  maintains  good  relationships  with  the  unions.   Employees  at
Washington Water, New Mexico Water, and Hawaii Water do not belong to unions.


d.   Financial  Information  about  Foreign and Domestic  Operations  and Export
     ---------------------------------------------------------------------------
     Sales.
     ------

The Company does not have export sales.

Item 1A. Risk Factors.

     Readers  and  prospective  investors  in our  securities  should  carefully
consider the following risk factors as well as the other  information  contained
or incorporated by reference in this report:

     The risks and  uncertainties  described  below are not the only ones facing
us.  Additional  risks  and  uncertainties  that  management  is not aware of or
focused on or that  management  currently  deems  immaterial may also impair our
business  operations.  This report is  qualified  in its  entirety by these risk
factors.

     If any of the following  risks  actually  occur,  the  Company's  financial
condition and results of operations could be materially and adversely  affected.
If this were to happen,  the value of the  Company's  securities  could  decline
significantly, and you could lose all or part of your investment.

Our business is heavily regulated and decisions by state regulatory  commissions
and changes in laws and regulations can significantly affect our business.

     California  Water  Service  Company,  New  Mexico  Water  Service  Company,
Washington  Water Service  Company and Hawaii Water Service  Company,  Inc., are
regulated  public  utilities  which provide water service to our customers.  The
rates  that the  Companies  charge  their  water  customers  are  subject to the
jurisdiction  of the  regulatory  commission  in the states in which we operate.
These  Commissions  set water rates for each  operating  district  independently
because the systems are not  interconnected.  The  Commissions  authorize  us to
charge  rates  which  they  consider  to be  sufficient  to  recover  our normal
operating  expenses,  to  provide  funds  for  adding  new  or  replacing  water
infrastructure,  and to allow us to earn what the  Commissions  consider to be a
fair and reasonable return on our invested capital.

     Our ability to meet our financial  objectives  is dependent  upon the rates
authorized by the Commissions.  We periodically file rate increase  applications
with the  Commissions.  The ensuing  administrative  and hearing  process may be
lengthy and costly. We can provide no assurances that our rate increase requests
will be granted by the Commissions. Even if approved, there is no guarantee that
approval will be given in a timely manner or at a sufficient  level to cover our
expenses and provide a reasonable  return on our  investment.  If the authorized
rates are  insufficient  to cover  operating  expenses  and capital  expenditure
requirements,  and allow a reasonable  return on invested  capital,  or the rate
increase decisions are delayed, our earnings may be adversely affected.

Our  liquidity  and  earnings  could  be  adversely  affected  by  increases  in
electricity prices.

     Purchased  power expense  represents  electricity  purchased to operate the
wells and pumps  which are needed to supply  water to our  customers.  Purchased
power is a significant operating expense.  During 2005 and 2004, purchased power
expense represented 7.9% and 8.5%,  respectively,  of our total operating costs.
These costs can and do increase  unpredictably  and in substantial  amounts,  as
occurred in California during 2001 when rates we paid for electricity  increased
48%. The  increases  are beyond our  control.  California  regulation  regarding

                                       17


recovery of increases in electric rates changed in 2001. For over 20 years prior
to 2001, the California Public Utilities Commission allowed recovery of electric
rate  increases  under its operating  rules.  However,  in 2001,  the Commission
revised its rules and deferred our recovery of the higher  electric  costs until
the filing of a general rate case.  In 2003,  the  California  Public  Utilities
Commission  reinstated  its policy to allow  utilities to adjust their rates for
rate  changes by the power  companies.  Cash  flows  between  general  rate case
filings  and  earnings  of  the  Company  maybe  adversely  impacted  until  the
Commission authorizes a rate change. The Company is allowed to track the expense
differences  caused by the rate  change and  request  future  recovery  which is
subject to an earnings test.

Changes in water supply costs directly affect our earnings.

     The cost to obtain water for delivery to our customers  varies depending on
the sources of supply,  wholesale  suppliers'  prices and the  quantity of water
produced  to supply  customer  water  usage.  Our  source  of  supply  varies by
operating  district.  Certain  districts  obtain all of their supply from wells,
some  districts  purchase all of the supply from  wholesale  suppliers and other
districts obtain the supply from a combination of well and purchased  sources. A
small  portion of the  supply is from  surface  sources  and  processed  through
Company-owned water treatment plants. On average, slightly more than half of the
water  delivered to  customers  is pumped from wells or received  from a surface
supply with the remainder  purchased from wholesale  suppliers.  During 2005 and
2004, the cost of purchased  water for delivery to customers  represented  33.5%
and 34.9%, respectively, of our total operating costs.

     Wholesaler water suppliers may increase their prices for water delivered to
us based on factors  that affect their  operating  costs.  Purchased  water rate
increases  are  beyond  our  control.  In  California,  our  ability  to recover
increases  in the  cost of  purchased  water  is  subject  to  decisions  by the
regulatory  commission.  If we are not allowed to recover the higher costs,  our
cash flows and our capital  resources and liquidity can be negatively  impacted.
Also, our profit margins may be adversely affected, unless the Commissions allow
us to seek reimbursement of those costs from our customers.

Environmental regulation has increased, and is expected to continue to increase,
our operating costs.

     Our water and wastewater services are governed by various federal and state
environmental  protection  and  health and safety  laws and  regulations.  These
provisions  establish  criteria for drinking  water and for discharges of water,
wastewater and airborne substances.  If we violate these provisions, we could be
subject to substantial fines or otherwise sanctioned.

     Environmental laws are complex and change  frequently.  They have tended to
become more  stringent over time. As new or stricter  standards are  introduced,
they could  increase our  operating  costs.  There can be no assurance  that the
Commissions  would  approve  rate  increases  to  enable  us  to  recover  these
additional compliance costs.

     We are  required  to test our  water  quality  for  certain  chemicals  and
potential  contaminants on a regular basis. If the test results indicate that we
exceed  allowable  limits,  we may be required  either to commence  treatment to
remove the contaminant or to develop an alternate water source.  Either of these
results may be costly,  and there can be no assurance that the Commissions would
approve  rate  increases  to enable us to recover  these  additional  compliance
costs.

     All of  the  above  factors  may  have a  material  adverse  effect  on our
business, financial position and results of operations.

The adequacy of our water supplies  depends upon a variety of factors beyond our
control. Interruption in the water supply may adversely affect our earnings.

     We depend on an adequate  water supply to meet the present and future needs
of our  customers.  Whether we have an adequate  supply varies  depending upon a
variety  of  factors,  including:  rainfall,  the  amount  of  water  stored  in

                                       18

reservoirs, underground water supply from which well water is pumped, changes in
the amount of water used by our customers,  water quality,  legal limitations on
water  use such as  rationing  restrictions  during a  drought,  and  population
growth.

     Also, the water  business is seasonal.  The normal water use pattern within
our service  territories  sees the highest  customer  usage and highest  revenue
during the warmer summer  months due  primarily to increased  usage for watering
outside  landscape,  cooling and swimming pools.  Customer usage and revenue are
lower during the cool,  rainy winter  months.  Demand also varies with  rainfall
levels.  If summer  temperatures  are  cooler  than  normal or the rainy  season
extends into the summer months or begins early in the fall months,  any of these
factors can cause a decline in customer usage and result in lower revenue.

     Drought  conditions  may affect our ability to serve our current and future
customers,  and may affect our customers' use of water.  Restrictions imposed on
the amount of water  customers are allowed to use during a drought may result in
decreased customer  billings.  Customers may use less water even after a drought
has passed because of conservation patterns developed during the drought.  Lower
use for any reason could lead to continued lower revenue.

     Since  the  September  11,  2001,  terrorist  attacks,  we have  heightened
security at our  facilities  and taken added  precautions  for the safety of our
employees  and water we deliver to our  customers.  We have also assigned a high
priority  to  completing  work  necessary  to  comply  with  new   Environmental
Protection Agency requirements  concerning  security of water facilities.  These
actions have increased our costs.

     The Company purchases its water supply from various  governmental  agencies
and others.  Water supply  availability  may be impacted by weather  conditions,
funding and other political and  environmental  considerations.  The Company has
entered into long-term agreements,  which commit the Company to payments whether
or not the  Company  purchases  any water.  For further  information  on Company
commitments, see the Water Supply section (page 11).

All of these factors may adversely affect our earnings and financial condition:

     Our business requires  significant capital  expenditures that are dependent
on our ability to secure appropriate funding.

     The water  utility  business is  capital-intensive.  We invest  significant
dollars to add or replace property,  plant and equipment. We fund these projects
from cash received from operations and funds received from  developers.  We also
borrow funds from banks under short-term bank lending arrangements.  We may seek
to meet our  long-term  capital  needs  by  raising  equity  through  common  or
preferred stock issues or issuing debt obligations.

     Water  shortages  may  adversely  affect us by  causing  us to rely on more
purchased water.  This could cause increases in capital  expenditures  needed to
build pipelines to secure alternative water sources.

     Our rate increase  applications  are designed to recover our investments in
utility plant. We cannot assure you that the rates the Commissions will allow us
to charge will be sufficient for this purpose.

     Moody's  Investor  Services,  Inc. and Standard & Poor's  Ratings  Services
issue  ratings  on  California  Water  Service  Company's  ability to repay debt
obligations.  The credit rating agencies could downgrade our credit rating based
on reviews of our financial  performance  and projections or upon the occurrence
of other  events that could impact our business  outlook.  In 2002,  Moody's and
Standard & Poor's did lower the ratings on California  Water  Service  Company's
first mortgage  bonds.  In 2003,  Moody's placed its rating on California  Water
Service  Company's  first  mortgage bonds on review for possible  downgrade.  In
February  2004,  Moody's  issued  a report  lowering  California  Water  Service
Company's  senior secured debt from A1 to A2 and noted the rating as stable.  In
November  2003,  Standard & Poor's issued a report keeping its rating of A+, but
changed its outlook from stable to negative.  Both cited concerns about the lack
of timely rate relief from the California  Public  Utilities  Commission and the
projected  capital  expenditure   requirements  for  water   infrastructure  and
environmental  compliance  needs.  Moody's  also issued a report about the water
industry,  citing the  difficulties  small  operators  face in financing  needed
capital expenditures and delays in commission rulings as two main concerns.  The

                                       19


rating  actions  were  attributed  to  delays in  receipt  of  decisions  by the
California  Public  Utilities  Commission  for rate  increase  applications  and
ongoing  capital   expenditures  to  maintain  water   infrastructure  and  meet
environmental  compliance  requirements.  A downgrade could increase our cost of
capital by causing potential  investors to require a higher interest rate due to
a  perceived  risk  increase  related to our ability to repay  outstanding  debt
obligations.  Lower  ratings by the agencies  could also restrict our ability to
access equity and debt capital.  During 2005, management met separately with the
two credit rating  agencies  during their annual rating  reviews.  Both agencies
maintain their ratings of A2 for Moody's and A+ for S&P as of the filing date of
this  report.  There is no  assurance  that the rating  agencies  will  maintain
ratings which allow us to borrow under advantageous conditions and at reasonable
interest rates.

     There is no assurance that our existing funding sources will continue to be
adequate or that the cost of funds will remain at levels permitting us to remain
profitable.

Any of these  factors may have an adverse  effect on our earnings and  financial
condition.

Risks  associated with potential  acquisitions or divestitures or  restructuring
may adversely affect us.

     We may seek to acquire or invest in other companies, technologies, services
or products that  complement  our business.  There is no assurance  that we will
succeed in finding  attractive  acquisition  candidates  or  investments.  These
transactions  may  result in the  issuance  of equity  securities  that could be
dilutive  if the  acquisition  or  business  opportunity  does  not  develop  in
accordance  with  our  business  plan.  They  may  also  result  in  significant
write-offs  and an increase in our debt.  The  occurrence of any of these events
could have a material  adverse effect on our business,  financial  condition and
results of operations.

     Any of these  transactions  could involve  numerous  additional  risks. For
example, we may experience  difficulty in getting required regulatory approvals.
We may also have  difficulty  assimilating  a new  business  or  separating  old
businesses.  Transactions such as these may also divert  management's  attention
from other business concerns and otherwise disrupt our business.  We might see a
loss  of  key  employees  from  our  acquisition  targets  and as a  result  the
integration of the new business  opportunity into our existing business might be
more difficult.

     All of these  events may have a material  adverse  effect on our  business.
There can be no assurance that we will be successful in overcoming  these or any
other significant risks encountered.

The accuracy of the  Company's  judgments  and  estimates  about  financial  and
accounting matters will impact operating results and financial condition.

     The discussion under "Critical  Accounting  Policies and Estimates" in this
report and the  information  referred to in that  discussion is  incorporated by
reference in this paragraph.  The Company makes certain  estimates and judgments
in  preparing  its  financial  statements.  The  quality  and  accuracy of those
estimates and judgments will have an impact on the Company's  operating  results
and financial condition.

The Company's controls and procedures may fail or be circumvented.

     Management  regularly  reviews and updates the Company's  internal  control
over financial  reporting,  disclosure  controls and  procedures,  and corporate
governance  policies  and  procedures.  Any system of controls  and  procedures,
however well designed and operated,  is based in part on certain assumptions and
can provide only reasonable, not absolute, assurances that the objectives of the
system are met.  Any failure or  circumvention  of the  Company's  controls  and
procedures  or failure  to comply  with  regulations  related  to  controls  and
procedures  could  have a material  adverse  effect on the  Company's  business,
results of operations and financial condition.

Item 1B. Unresolved Staff Comments.  None

                                       20


Item 2.  Properties.

The Company's  physical  properties  consist of offices and water  facilities to
accomplish the production,  storage, treatment, and distribution of water. These
properties are located in or near the  Geographic  Service Areas listed above in
Item 1.c.  "Narrative  Description of the Business." The general  office,  which
houses   accounting,   engineering,   information   systems,   human  resources,
purchasing,  regulatory,  water quality,  and executive staff, is located in San
Jose, California. All properties are maintained in good operating condition.

The real properties owned are held in fee simple title.  Properties owned by Cal
Water are subject to the indenture  securing  first  mortgage bonds of which $27
million  remained  outstanding  at  December  31,  2005.  Washington  Water  has
long-term  bank loans that are secured  primarily by utility  plant.  New Mexico
Water has a long-term loan which is secured by utility plant.

Cal Water  owns 628 wells and  operates  5 leased  wells.  There  were 387 owned
storage tanks with a capacity of 252 million  gallons,  43 managed storage tanks
with a capacity of 35 million  gallons,  and 3 reservoirs with a capacity of 220
million gallons.  There are 5,453 miles of supply and distribution  mains in the
various systems.

Washington  Water  owns 314 wells  and  manages  85  wells.  There are 115 owned
storage tanks and 28 managed storage tanks with a storage  capacity of 6 million
gallons. There are 309 miles of supply and distribution lines.

New  Mexico  Water  owns 11  wells.  There are 8  storage  tanks  with a storage
capacity of 4 million  gallons.  There are 138 miles of supply and  distribution
lines.

Hawaii Water owns 6 wells.  There are 3 storage tanks with a storage capacity of
5 million gallons. There are 35 miles of supply and distribution lines.

In the leased City of Hawthorne and City of Commerce  systems or in systems that
are operated under contract for  municipalities or private  companies,  title to
the  various  properties  is held  exclusively  by the  municipality  or private
company.

Water  supply,   security,   environmental,   condemnation   and  utility  plant
construction  items are  discussed  in Item 1.c,  "Narrative  of the  Business."
Utility plant  construction  items are also  discussed in Item 7,  "Management's
Discussion  and  Analysis of  Financial  Condition  and Results of  Operations -
LIQUIDITY AND CAPITAL RESOURCES."

Item 3.  Legal Proceedings.

In 1995, the State of California's Department of Toxic Substances Control (DTSC)
named  Cal  Water  as a  potential  responsible  party  for  cleanup  of a toxic
contamination  plume in the Chico  groundwater.  The toxic spill  occurred  when
cleaning  solvents,  which were discharged into the city's sewer system by local
dry cleaners,  leaked into the underground water supply.  The DTSC contends that
Cal Water's  responsibility stems from its operation of wells in the surrounding
vicinity  that  caused the  contamination  plume to  spread.  While Cal Water is
cooperating with the cleanup effort, Cal Water denies any responsibility for the
contamination  or the  resulting  cleanup and intends to  vigorously  resist any
action that may be brought  against Cal Water.  In December  2002, Cal Water was
named along with other  defendants in two lawsuits filed by DTSC for the cleanup
of the plume.  The suits assert that the  defendants  are jointly and  severally

                                       21


liable for the estimated  cleanup of $8.7 million.  The parties have  undertaken
settlement  negotiations.  In response to Cal Water's  request to participate in
settlement  negotiations,  the  insurance  carrier  threatened  to exercise  its
reservation of right letter to seek  reimbursement  of past defense costs.  Past
defense  costs  approximate  $0.6 million.  Cal Water  believes that the carrier
clearly  has a  duty  to  defend  and  is  not  entitled  to  any  defense  cost
reimbursement.  Furthermore,  Cal Water believes that insurance  coverage exists
for this claim. If Cal Water's claim is ultimately  found to be excludable under
its policies,  Cal Water  believes any damages will be covered by the ratepayer,
as  pump-and-treat  is the most economical  approach to the cleanup effort.  Cal
Water believes that there will not be a material adverse effect to its financial
position or results of operations.

In 1995, the  California  Legislature  enacted the Water Utility  Infrastructure
Improvement  Act of 1995  (Infrastructure  Act) to encourage  water utilities to
sell surplus  properties  and reinvest in needed water  utility  facilities.  In
September  2003,  the CPUC issued  decision  D.03-09-021 in Cal Water's 2001 GRC
filing.  In this  decision,  the CPUC  ordered Cal Water to file an  application
setting  up  an  Infrastructure   Act  memorandum  account  with  an  up-to-date
accounting  of all real  property that was at any time in rate base and that Cal
Water had sold since the effective date of the Infrastructure Act. Additionally,
the decision  directed the CPUC staff to file a detailed report on its review of
Cal Water's application. On January 11, 2005, the ORA issued a report expressing
its opinion  that Cal Water had not proven that  surplus  properties  sold since
1996 were no longer used and useful. The ORA recommended that Cal Water be fined
$160,000 and that gains from property sales should generally benefit ratepayers.

During the period  under  review,  Cal  Water's  cumulative  gains from  surplus
property sales were $19.2 million,  which included an intercompany  gain related
to a  transaction  with Utility  Services and a like-kind  exchange with a third
party.

On December 1, 2005, the CPUC issued its  D.05-12-002.  This decision finds that
Cal Water  appropriately  reclassified  all properties as  non-utility  property
prior to being sold and that  criteria  Cal Water  followed  to  reclassify  its
properties  was reasonable and  consistent  with the  requirements  of the CPUC.
Since the properties were properly reclassified, the CPUC found that approval of
the property sales was not required and no penalty was  warranted.  Furthermore,
the decision  found that Cal Water should be allowed to include in rate base the
remaining $1,182,462 of the Chico customer center.

Although the decision  concluded that all gains for the property sales qualified
for reinvestment in accordance with the Infrastructure  Act, the decision defers
the  ratemaking  issue  regarding  treatment  of  sale  proceeds  to  its  Order
Instituting Rulemaking (R.) 04-09-003.  On November 5, 2005, the CPUC mailed its
draft decision  (Draft  Decision)  regarding the allocation of proceeds from the
sale of utility  assets.  The Draft  Decision  states  that the CPUC has limited
discretion  in how it allocates  gains on sale of real  property  that meets the
criteria in the  Infrastructure  Act, provided that water companies reinvest the
proceeds in new water  infrastructure.  If the Draft  Decision  is adopted,  the
Company  will be entitled  to earn its full  authorized  return on the  proceeds
reinvested in utility plant.

Based on the D.  05-12-002 and the Draft  Decision,  Cal Water has not accrued a
liability  in its  financial  statements.  Cal Water does not know when the CPUC
will  issue its  decision  in the matter of  R.04-09-003.  If the CPUC finds any
portion of the property sales should be allocated to the ratepayer,  Cal Water's
rate base could be reduced,  which would lower future revenues,  net income, and
cash flows.

Periodically, the Company is involved in other proceedings or litigation arising
in the  ordinary  course  of  business.  Management  does not  believe  that the
ultimate  resolution  of these  matters  will  materially  affect the  Company's
financial position, results of operations, or cash flows.


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

No matters were submitted to a vote of security holders in the fourth quarter of
2005.

Executive Officers of the Registrant
- ------------------------------------



Name                        Positions and Offices with California Water Service Group                Age
- ----                        ---------------------------------------------------------                ---
                                                                                                
Robert W. Foy               Chairman of the Board since January 1, 1996.  A director since            69
(1)                         1977.  Formerly President and Chief Executive Officer of Pacific
                            Storage Company, a diversified transportation and warehousing
                            company with operations in Stockton, Modesto, Sacramento,
                            San Jose, Vallejo, Merced and Auburn, California, where he has
                            been employed for 42 years

                                       22


Peter C. Nelson             President and Chief Executive Officer since February 1, 1996.             58
(2)                         Formerly Vice President, Division Operations (1994-1995) and
                            Region  Vice President (1989-1994), Pacific Gas & Electric
                            Company, a gas and electric public utility

John S. Tootle              Acting CFO and Treasurer since October 28, 2005; Formerly                 51
(3)                         Corporate Counsel from 2000-2005 and previously CFO
                            Dominguez Services Corporation

Dan Stockton                Vice President, Corporate Development and Corporate Secretary             61
(4)                         since October 2005; Vice President, Information Systems from
                             April 2001 to September 2005; from 1991 to 2001 he
                            served as Chief Operating Officer of Great Oaks Water Company

Calvin L. Breed             Controller, Assistant Secretary and Assistant Treasurer since             50
(5)                         Nov. 1994; previously Treasurer of TCI International, Inc. (1984-1994);
                            a certified public accountant with Arthur Andersen & Co. (1980-1983)


(1)  Holds the same position with California Water Service  Company,  New Mexico
     Water  Service  Company,  Washington  Water Service  Company,  Hawaii Water
     Service Company, Inc., and CWS Utility Services

(2)  Holds the same  position  with  California  Water  Service  Company and CWS
     Utility  Services;  Chief  Executive  Officer of New Mexico  Water  Service
     Company, Washington Water Service Company and Hawaii Water Service Company,
     Inc.

(3)  Holds the same position with California Water Service  Company,  New Mexico
     Water  Service  Company,  Washington  Water Service  Company,  Hawaii Water
     Service Company, Inc., and CWS Utility Services.

(4)  Vice  President,  and  Corporate  Secretary  of  California  Water  Service
     Company,  New  Mexico  Water  Service  Company,  Washington  Water  Service
     Company, Hawaii Water Service Company, Inc., and CWS Utility Services

(5)  Holds the same position with California Water Service Company

                                       23



Name                        Positions and Offices with California Water Service Company                Age
- ----                        -----------------------------------------------------------                ---
                                                                                                 
Paul G. Ekstrom             Vice President Customer Service and Information Systems since               54
                            October 2005; Corporate Secretary, 1996 to 2005; Operations
                            Coordinator, 1993 to 1996; District Manager, Livermore, 1988 to
                            1993; previously served in various field management positions
                            since 1979; an employee since 1972

Francis S. Ferraro          Vice President, Regulatory Matters and Corporate Relations since            56
(1)                         October 2005; Vice President, Regulatory Matters and Corporate
                            Development, 2001 to 2005; Vice President, Regulatory Matters,
                            1989 to 2001.  Employed by the California Public Utilities
                            Commission for 16 years, including 1985 through 1989 as an
                            Administrative Law Judge; an employee since 1989

Robert R. Guzzetta          Vice President, Operations since October 2005; Vice President               51
                            Engineering and Water Quality from 1996 to 2005; Assistant Chief
                            Engineer, 1988 to 1990; various engineering department positions
                            since 1977

Christine L. McFarlane      Vice President, Human Resources since August 1996; Director                 59
                            of Human Resources, 1991 to 1996; Assistant Director of
                            Personnel, 1989 to 1991; an employee since 1969

Michael Rossi               Vice President, Engineering and Water Quality since October 2005;           52
(2)                         Chief Engineer from 1997 to 2005; Assistant Chief Engineer from 1988
                            to 1997; an employee since 1977



(1)  Also, Vice President,  Corporate Relations with CWS Utility Services,  Vice
     President,  Regulatory Matters with Hawaii Water Service Company, Inc., and
     Vice President, Regulatory Matters with New Mexico Water Service Company.

(2)  Also, Vice President, Engineering with CWS Utility Services.



Name                        Positions and Offices with Washington Water Service Company               Age
- ----                        -----------------------------------------------------------               ---

                                                                                                
Michael P. Ireland          President since December 1999; previously President of Harbor Water       52
                            Company, Gig Harbor, Washington from 1985 to 1999


No  officer  or  director  has any family  relationship  to any other  executive
officer or director.  No executive  officer is appointed for any set term. There
are no agreements or understandings  between any executive officer and any other
person pursuant to which he/she was selected as an executive officer.

                                       24


                                     PART II

Item 5.     Market for Registrant's  Common Equity,  Related Stockholder Matters
            and Issuer Purchases of Equity Securities

The Company's  common stock is traded on the New York Stock  exchange  under the
symbol  "CWT." At December 31, 2005,  there were  18,389,996  common  shares and
139,000 preferred shares outstanding and 3,161 stockholders of record.

Additional  information  required  by this  Item  is  contained  in the  section
captioned  "Quarterly  Financial Data" in the 2005 Annual Report to Stockholders
and is incorporated herein by reference.  The 2005 Annual Report to Stockholders
is included with this report as Exhibit 13.1.


Item 6.     Selected Financial Data.

The  information  required by this Item is  contained  in the section  captioned
"Ten-Year  Financial  Review" in the 2005 Annual Report to  Stockholders  and is
incorporated  herein by  reference.  The 2005 Annual Report to  Stockholders  is
included with this report as Exhibit 13.1.


Item 7.     Management's  Discussion  and  Analysis of Financial  Condition  and
            Results of Operations.

The  information  required by this Item is  contained  in the section  captioned
"Management's  Discussion  and  Analysis of Financial  Condition  and Results of
Operations,"  in the 2005  Annual  Report to  Stockholders  and is  incorporated
herein by  reference.  The 2005 Annual Report to  Stockholders  is included with
this report as Exhibit 13.1.


Item 7A.    Quantitative and Qualitative Disclosures About Market Risk

The  information  required by this Item is  contained  in the section  captioned
"Financial  Risk  Management" in the 2005 Annual Report to  Stockholders  and is
incorporated  herein by  reference.  The 2005 Annual Report to  Stockholders  is
included with this report as Exhibit 13.1.


Item 8.     Financial Statements and Supplementary Data.

The information  required by this Item is contained in the 2005 Annual Report to
Stockholders and is incorporated herein by reference.  The 2005 Annual Report to
Stockholders is included with this report as Exhibit 13.1.


Item 9.     Changes in and  Disagreements  with  Accountants  on Accounting  and
            Financial Disclosure.

None

                                       25


Item 9A.    Controls and Procedures

The information required by this Item is contained in the sections "Controls and
Procedures" and "Report of Independent Registered Public Accounting Firm" in the
2005 Annual Report to Stockholders and is incorporated herein by reference.  The
2005 Annual Report to Stockholders is included with this report as Exhibit 13.1.


Item 9B.    Other Information

None.


                                    PART III

Item 10.    Directors and Executive Officers of the Registrant.

The  information  required  by  this  Item as to  directors  of the  Company  is
contained in the sections captioned "Board Structure,"  "Proposals of the Board;
Proposal No. 1 - Election of Directors"  and "Other Matters - Code of Ethics" of
the 2006 Proxy Statement,  and is incorporated herein by reference.  Information
regarding  executive  officers  is  included  in a  separate  section  captioned
"Executive Officers of the Registrant" contained in Part I of this report.

Effective March 13, 2006, the Company appointed Martin (Marty) A. Kropelnicki as
Vice  President,  Chief  Financial  Officer and Treasurer.  Prior to joining the
Company,   Mr.  Kropelnicki  was  the  Chief  Financial  Officer  of  PowerLight
Corporation.


Item 11.    Executive Compensation.

The information required by this Item as to directors of the Company is included
under  the  caption  "Director  Compensation  Arrangements"  of the  2006  Proxy
Statement and is incorporated herein by reference.  The information  required by
this Item as to compensation of executive  officers,  including officers who are
directors,  is included under the caption  "Executive  Compensation" of the 2006
Proxy Statement and is incorporated herein by reference.


Item 12.    Security Ownership of Certain Beneficial Owners and Management

The  information  required by this Item is  contained  in the section  captioned
"Stock Ownership of Management and Certain  Beneficial Owners" of the 2006 Proxy
Statement and is incorporated herein by reference.


Item 13.    Certain Relationships and Related Transactions.

Cal Water provides  laboratory  services to a subsidiary of SJW Corp., which has
ownership  of over 5% of the  Company's  common  stock  outstanding.  The  rates
charged are comparable to rates charged to other third parties.  The revenue for
2005 was less than $0.1  million.  The revenue and income from these  activities
are not significant to the business.

                                       26

Item 14.    Principal Accountant Fees and Services

The  information  required by this Item is  contained  in the section  captioned
"Relationship  with the Independent  Registered  Public  Accounting Firm" of the
2006 Proxy Statement and is incorporated herein by reference.


                                     PART IV

Item 15.    Exhibits, Financial Statement Schedules.

(a) As part of this Form 10-K, the following documents are being filed:

     1. Financial Statements:

          Consolidated Balance Sheets as of December 31, 2005 and 2004

          Consolidated  Statements  of Income for the years ended  December  31,
          2005, 2004 and 2003

          Consolidated   Statements   of   Common   Stockholders'   Equity   and
          Comprehensive  Income for the years ended December 31, 2005,  2004 and
          2003

          Consolidated Statements of Cash Flows for the years ended December 31,
          2005, 2004 and 2003

          Notes to Consolidated  Financial  Statements,  December 31, 2005, 2004
          and 2003

          Reports of Independent Registered Public Accounting Firm

          Controls and Procedures

          The above financial  statements are contained in sections  bearing the
          same captions in the 2005 Annual Report to Stockholders which is filed
          with this Form 10-K and  incorporated  herein by  reference.  Refer to
          Exhibit 13.1 of this Form 10-K.

     2.   Financial  Statement  Schedules:  No financial statement schedules are
          being included since the information otherwise required is included in
          the financial statements and the notes thereto.

     3.   Exhibits  required  to be  filed by Item 601 of  Regulation  S-K:  The
          Exhibit Index on page 30 of this Form 10-K is  incorporated  herein by
          reference.

          (a)  The exhibits filed as part of this Form 10-K are attached, unless
               otherwise  indicated.  The exhibits  listed in the Exhibit  Index
               that are not filed with this Form 10-K were previously filed with
               the  Securities  and Exchange  Commission  as  indicated  and are
               hereby incorporated by reference.


          (b)  Exhibits  required  to be filed by Item  601 of  Regulation  S-K.
               Refer to Item  (a) 3 above  and the  Exhibit  Index on page 30 of
               this Form 10-K.

          (c)  Additional Financial Statement Schedules. No filings are required
               under this Item.

                                       27

                                   SIGNATURES

Pursuant to the  requirements of Section 13 or 15(d) 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

Date: February 22, 2006                   By /s/ Peter C. Nelson
                                          PETER C. NELSON,
                                          President and Chief Executive Officer


Pursuant to the requirements of the Securities Exchange Act of 1934, this report
has been signed below by the following  persons on behalf of the  Registrant and
in the capacities and on the dates indicated:

Date: February 22, 2006                   /s/ Robert W. Foy
                                          ROBERT W. FOY
                                          Chairman, Board of Directors

Date: February 22, 2006                   /s/ Douglas M. Brown
                                          DOUGLAS M. BROWN
                                          Member, Board of Directors

Date: February 22, 2006                   /s/ Edward D. Harris, Jr.
                                          EDWARD D. HARRIS, JR., M.D.
                                          Member, Board of Directors

Date: February 22, 2006                   /s/ Bonnie G. Hill
                                          BONNIE G. HILL
                                          Member, Board of Directors

Date: February 22, 2006                   /s/ David N. Kennedy
                                          DAVID N. KENNEDY
                                          Member, Board of Directors

Date: February 22, 2006                   /s/ Richard P. Magnuson
                                          RICHARD P. MAGNUSON
                                          Member, Board of Directors

Date: February 22, 2006                   /s/ Linda R. Meier
                                          LINDA R. MEIER
                                          Member, Board of Directors

Date: February 22, 2006                   /s/ Peter C. Nelson
                                          PETER C. NELSON
                                          President and Chief Executive Officer,
                                          Principal Executive Officer
                                          Member, Board of Directors

Date: February 22, 2006                   /s/ George A. Vera
                                          GEORGE A. VERA
                                          Member, Board of Directors

                                       28


Date: February 22, 2006                   /s/ John S. Tootle
                                          JOHN S. TOOTLE
                                          Acting Chief Financial
                                          Officer and Treasurer;
                                          Principal Financial Officer

Date: February 22, 2006                   /s/ Calvin L. Breed
                                          CALVIN L. BREED
                                          Controller, Assistant Secretary and
                                          Assistant Treasurer;
                                          Principal Accounting Officer

                                       29


                                  EXHIBIT INDEX

Exhibit
Number
- ------

     Unless filed with this Form 10-K, the documents  listed are incorporated by
     reference to the filings referred to:

3.   Articles of Incorporation and Bylaws:

     3.1    Certificate  of  Incorporation  of  California  Water  Service Group
            (Filed as Exhibit B of the  California  Water  Service  Group  Proxy
            Statement dated March 18, 1999)

     3.2    Restated  Bylaws of  California  Water  Service  Group as amended on
            January 26, 2000  (Exhibit  E-2 to Current  Report on Form 8-K filed
            February 3, 2000)

4.   Instruments  Defining the Rights of Security  Holders of  California  Water
     Service Group, including Indentures:


     4.1    Shareholder  Rights Plan;  an  agreement  between  California  Water
            Service Group and BankBoston,  N.A., rights agent, dated January 28,
            1998 (Exhibit 1 to Registration Statement on Form 8-A filed February
            13, 1998)

     4.2    Certificate  of  Designations   regarding   Series  D  Participating
            Preferred  Stock,  as  filed  with  Delaware  Secretary  of State on
            September  16, 1999  (Exhibit 4.2 to Annual  Report on Form 10-K for
            the year ended December 31, 2003)

     4.3    Thirty-fourth  Supplemental  Indenture dated as of November 1, 1990,
            covering First Mortgage 9.86% Bonds, Series CC. (Exhibit 4 to Annual
            Report on Form 10-K for the year ended December 31, 1990)

     4.4    [reserved]

     4.5    [reserved]

     4.6    [reserved]

     4.7    Note  Agreement  dated  August 15, 1995,  pertaining  to issuance of
            $20,000,000,  7.28% Series A Unsecured Senior Notes, due November 1,
            2025  (Exhibit 4 to  Quarterly  Report on Form 10-Q for the  quarter
            ended September 30, 1995)

     4.8    Note  Agreement  dated  March 1, 1999,  pertaining  to  issuance  of
            $20,000,000,  6.77% Series B Unsecured Senior Notes, due November 1,
            2028  (Exhibit 4.1 to Annual  Report on Form 10-K for the year ended
            December 31, 1999)

                                       30


     4.9    First  Supplement  dated October 1, 2000, to Note Agreement of March
            1, 1999,  pertaining  to issuance  of  $20,000,000,  8.15%  Series C
            Unsecured Senior Notes, due November 1, 2030 (Exhibit 4.12 to Annual
            Report on Form 10-K for year ended December 31, 2000)

     4.10   Second  Supplement  dated  September 1, 2001,  to Note  Agreement of
            March 1, 1999, pertaining to issuance of $20,000,000, 7.13% Series D
            Unsecured  Senior  Notes,  due  November  1,  2031  (Exhibit  4.1 to
            Quarterly  Report on Form 10-Q for the quarter  ended  September 30,
            2001)

     4.11   Third  Supplement  dated May 1, 2002, to Note  Agreement of March 1,
            1999,  pertaining  to  issuance  of  $20,000,000,   7.11%  Series  E
            Unsecured  Senior  Notes,  due May 1, 2032 (Exhibit 4.1 to Quarterly
            Report on Form 10-Q for the quarter ended June 30, 2002)

     4.12   Fourth  Supplement dated August 15, 2002, to Note Agreement of March
            1, 1999,  pertaining  to issuance  of  $20,000,000,  5.90%  Series F
            Unsecured Senior Notes, due November 1, 2017 (Exhibit 4.14 to Annual
            Report on Form 10-K for the year ended December 31, 2002)

     4.13   Fifth  Supplement dated November 1, 2002, to Note Agreement of March
            1, 1999,  pertaining  to issuance  of  $20,000,000,  5.29%  Series G
            Unsecured Senior Notes, due November 1, 2022 (Exhibit 4.15 to Annual
            Report on Form 10-K for the year ended December 31, 2002)

     4.14   Sixth  Supplement dated December 1, 2002, to Note Agreement of March
            1, 1999,  pertaining  to issuance  of  $20,000,000,  5.29%  Series H
            Unsecured Senior Notes, due December 1, 2022 (Exhibit 4.16 to Annual
            Report on Form 10-K for the year ended December 31, 2002)

     4.15   Ninth Supplement dated February 15, 2003, to Note Agreement of March
            1, 1999,  pertaining  to issuance  of  $10,000,000,  4.58%  Series K
            Unsecured  Senior  Notes,  due June 30, 2010 (Exhibit 4.17 to Annual
            Report on Form 10-K for the year ended December 31, 2002)

     4.16   Tenth Supplement dated February 15, 2003, to Note Agreement of March
            1, 1999,  pertaining  to issuance  of  $10,000,000,  5.48%  Series L
            Unsecured  Senior  Notes,  due March 1, 2018 (Exhibit 4.18 to Annual
            Report on Form 10-K for the year ended December 31, 2002)

     4.17   Thirteenth  Supplemental  Trust Indenture  whereby  California Water
            Service Company became the successor to Dominguez Water  Corporation
            in the original  trust  indenture  for Dominguez  Water  Corporation
            dated August 1, 1954 (Exhibit 4.13 to Annual Report on Form 10-K for
            the year ended  December 31, 2000  [included  within Exhibit 4.12 to
            such report])

     4.18   Eleventh  Supplemental Trust Indenture dated as of December 8, 1992,
            covering  First  Mortgage  8.86%  Bonds,  Series J (Exhibit  10.2 to
            Annual Report on Form 10-K for the year ended  December 31, 1997, of
            Dominguez Services Corporation)

                                       31


     4.19   Twelfth  Supplemental  Indenture  dated  as  of  December  1,  1997,
            covering First Mortgage 6.94% Bonds, Series K due 2012 (Exhibit 10.3
            to Annual Report on Form 10-K for the year ended  December 31, 1997,
            of Dominguez Services Corporation)

     4.20   Seventh  Supplement dated May 1, 2003, to Note Agreement of March 1,
            1999,  pertaining  to  issuance  of  $10,000,000,   5.54%  Series  I
            Unsecured  Senior Notes,  due May 1, 2023 (Exhibit 4.22 to Quarterly
            Report on Form 10-Q for the quarter ended March 31, 2003)

     4.21   Amended and Restated  Eighth  Supplement  dated May 1, 2003, to Note
            Agreement of March 1, 1999,  pertaining to issuance of  $10,000,000,
            5.44% Series J Unsecured Senior Notes, due May 1, 2018 (Exhibit 4.23
            to  Quarterly  Report on Form 10-Q for the  quarter  ended March 31,
            2003)

     4.22   Twelfth  Supplement  dated  October 24, 2003,  to Note  Agreement of
            March 1, 1999,  pertaining  to the issuance of  $20,000,000,  5.55%,
            Series N Unsecured Senior Notes due December 1, 2013,  (Exhibit 4.24
            to Quarterly Report on Form 10-Q for the quarter ended September 30,
            2003)

     4.23   Eleventh  Supplement  dated  November 3, 2003, to Note  Agreement of
            March 1, 1999,  pertaining  to the issuance of  $20,000,000,  5.52%,
            Unsecured  Series M Senior Notes due November 1, 2013  (Exhibit 4.25
            to Quarterly Report on Form 10-Q for the quarter ended September 30,
            2003)

10.  Material Contracts.

     10.1   Water Supply Contract between Cal Water and County of Butte relating
            to Cal Water's Oroville District;  Water Supply Contract between Cal
            Water and the Kern  County  Water  Agency  relating  to Cal  Water's
            Bakersfield  District;  Water Supply Contract  between Cal Water and
            Stockton  East  Water  District  relating  to Cal  Water's  Stockton
            District.  (Exhibits 5(g), 5(h), 5(i), 5(j),  Registration Statement
            No. 2-53678,  which exhibits are incorporated by reference to Annual
            Report on Form 10-K for the year ended December 31, 1974)

     10.2   Settlement  Agreement  and Master Water Sales  Contract  between the
            City and County of San  Francisco  and Certain  Suburban  Purchasers
            dated August 8, 1984;  Supplement to Settlement Agreement and Master
            Water Sales  Contract,  dated August 8, 1984;  Water Supply Contract
            between Cal Water and the City and County of San Francisco  relating
            to Cal  Water's  Bear Gulch  District  dated  August 8, 1984;  Water
            Supply  Contract  between  Cal Water and the City and  County of San
            Francisco  relating  to the Cal Water's  San Carlos  District  dated
            August 8, 1984; Water Supply Contract between Cal Water and the City
            and  County  of San  Francisco  relating  to Cal  Water's  San Mateo
            District  dated August 8, 1984;  Water Supply  Contract  between Cal
            Water  and the City and  County  of San  Francisco  relating  to Cal
            Water's South San Francisco District dated August 8, 1984.  (Exhibit
            10.2 to  Annual  Report  on Form  l0-K for the year  ended  December
            31,1984)

                                       32


     10.3   Water Supply Contract dated January 27, 1981,  between Cal Water and
            the Santa Clara  Valley Water  District  relating to Cal Water's Los
            Altos  District  (Exhibit 10.3 to Annual Report on Form 10-K for the
            year ended December 31, 1992)

     10.4   Amendments  No. 3, 6 and 7 and  Amendment  dated June 17,  1980,  to
            Water  Supply  Contract  between  Cal Water and the  County of Butte
            relating to Cal Water's Oroville  District.  (Exhibit 10.5 to Annual
            Report on Form 10-K for the year ended December 31, 1992)

     10.5   Amendment dated May 31, 1977, to Water Supply  Contract  between Cal
            Water and  Stockton  East Water  District  relating  to Cal  Water's
            Stockton  District.  (Exhibit 10.6 to Annual Report on Form 10-K for
            the year ended December 31, 1992)

     10.6   Second  Amended  Contract dated  September 25, 1987,  among Stockton
            East Water District,  California Water Service Company,  the City of
            Stockton, the Lincoln Village Maintenance District, and the Colonial
            Heights  Maintenance  District  Providing  for the  Sale of  Treated
            Water.  (Exhibit  10.7 to  Annual  Report  on Form 10-K for the year
            ended December 31, 1987)

     10.7   Water  Supply  Contract  dated  April  19,  1927,  and  Supplemental
            Agreement dated June 5, 1953,  between Cal Water and Pacific Gas and
            Electric Company relating to Cal Water's Oroville District. (Exhibit
            10.9 to Annual  Report on Form 10-K for the year ended  December 31,
            1992)

     10.8   [reserved]

     10.9   [reserved]

     10.10  Agreement between the City of Hawthorne and California Water Service
            Company for the 15-year lease of the City's water  system.  (Exhibit
            10.17 to Quarterly  Report on Form 10-Q for the quarter  ended March
            31, 1996)

     10.11  Water Supply Agreement dated September 25, 1996, between the City of
            Bakersfield and California Water Service Company.  (Exhibit 10.18 to
            Quarterly  Report on Form 10-Q for the quarter  ended  September 30,
            1996)

     10.12  Water Supply  Contract dated November 16, 1994,  between  California
            Water  Service  Company and Alameda  County Flood  Control and Water
            Conservation  District  relating to Cal Water's  Livermore  District
            (Exhibit  10.15 to Annual  Report  on Form  10-K for the year  ended
            December 31, 1994)

     10.13  [reserved]

     10.14  California  Water  Service  Group  Directors'  Retirement  Plan  (As
            amended and restated on February 22, 2006)*

                                       33



     10.15  [reserved]

     10.16  $10,000,000  Business  Loan  Agreement  between  Bank of America and
            California  Water  Service  Group  and CWS  Utility  Services  dated
            February 28, 2003  (Exhibit  10.17 to Annual Report on Form 10-K for
            the year ended December 31, 2002)

     10.17  $55,000,000  Business  Loan  Agreement  between  Bank of America and
            California  Water Service  Company dated  February 28, 2003 (Exhibit
            10.18 to Annual Report on Form 10-K for the year ended  December 31,
            2002)

     10.18  Executive  Severance  Plan  (Exhibit  10.24 to Annual Report on Form
            10-K for the year ended December 31, 1998) *

     10.19  California  Water Service Group  Long-Term  Incentive Plan (filed as
            Appendix A of the  California  Water Service  Group proxy  statement
            dated March 17, 2000) *

     10.20  California Water Service Group Deferred  Compensation Plan effective
            January 1, 2001 (Exhibit 10.22 to Annual Report on Form 10-K for the
            year ended December 31, 2000) *

     10.21  California Water Service Company  Supplemental  Executive Retirement
            Plan  effective  January 1, 2001 (Exhibit  10.23 to Annual Report on
            Form 10-K for the year ended December 31, 2000) *

     10.22  Amendment No. 1 to California  Water  Service  Company  Supplemental
            Executive  Retirement Plan effective  January 1, 2001 (Exhibit 10.22
            to Quarterly Report on Form 10-Q for the quarter ended September 30,
            2004)*

     10.23  Amendment No. 1 effective  June 25, 2003, to agreement  with Bank of
            America dated February 28, 2003 (Exhibit  10.24 to Quarterly  Report
            on Form 10-Q for the quarter ended June 30, 2003)

     10.24  Water Supply  Contract  99-73  between the City of  Bakersfield  and
            California  Water  Service  Company,  dated March 31, 1999  (Exhibit
            10.25  to  Quarterly  Report  on Form  10-Q  for the  quarter  ended
            September 30, 2003)

     10.25  Amendment  No.  1 to  Water  Supply  Contract  between  the  City of
            Bakersfield and California Water Service  Company,  dated October 3,
            2001 (Exhibit 10.26 to Quarterly Report on Form 10-Q for the quarter
            ended September 30, 2003)

     10.26  Amendment No. 2 effective  February 18, 2004, to agreement with Bank
            of America dated  February 28, 2003 (Exhibit  10.26 to Annual Report
            on Form 10-K for the year ended December 31, 2003)

     10.27  Amendment No. 2 to California  Water  Service  Company  Supplemental
            Executive  Retirement Plan effective  January 1, 2001 (Exhibit 10.27
            to Quarterly Report on Form 10-Q for the quarter ended September 30,
            2004)*

     10.28  $10,000,000  Business Loan Agreement  between Bank of America,  N.A.
            and California Water Service Group, CWS Utility Services, New Mexico
            Water Service Company,  Washington Water Service Company, and Hawaii
            Water Service Company,  Inc., dated December 23, 2004. (Exhibit 10.1
            to Current Report on Form 8-K filed on February 8, 2005)

                                       34



     10.29  $45,000,000  Business Loan Agreement  between Bank of America,  N.A.
            and  California  Water  Service  Company  dated  December  23, 2004.
            (Exhibit  10.2 to Current  Report on Form 8-K filed on  February  8,
            2005)

     10.30  California  Water  Service  Group  Equity  Incentive  Plan (filed as
            Appendix B of the  California  Water Service  Group proxy  statement
            dated March 25, 2005, for its Annual Meeting of  Stockholders  to be
            held on April 27,  2005,  as filed  with the SEC on March  22,  2005
            (File No. 1-13883))*

     10.31  The  registrant's  policy  on  option  repricing  under  its  Equity
            Incentive Plan  (incorporated by reference to Item 8.01 Other Events
            in the registrant's  Current Report on Form 8-K dated April 7, 2005)
            *

     10.32  Water Supply  Contract dated  September 21, 2005,  between Cal Water
            and the Kern County Water Agency. (Exhibit 10.1 to Current Report on
            Form 8-K filed on September 21, 2005)

     10.33  Separation  Agreement  between  California  Water  Service Group and
            Richard D. Nye.  (Exhibit 10 to Current  Report on Form 8-K filed on
            December 22, 2005)*

     10.34  Form of Stock  Appreciation  Right Grant Notice under the California
            Water Service Group Equity Incentive Plan*

     10.35  Form of Stock  Appreciation  Right  Agreement  under the  California
            Water Service Group Equity Incentive Plan with Notice of Exercise*

     10.36  Form of  Restricted  Stock Award Grant Notice  under the  California
            Water Service Group Equity Incentive Plan*

     10.37  [reserved]

     10.38  Form of Restricted  Stock Award Agreement under the California Water
            Service Group Equity  Incentive Plan with  Assignment  Separate From
            Certificate and Joint Escrow Instructions*

     10.39  Form of Stock  Option Grant  Notice for outside  director  under the
            California Water Service Group Equity Incentive Plan*

     10.40  Form of Stock Option Grant Notice under the California Water Service
            Group Equity Incentive Plan*

     10.41  Form  of  Stock  Option   Agreement   (Incentive   Stock  Option  or
            Nonstatutory  Stock Option) under the California Water Service Group
            Equity Incentive Plan with Notice of Exercise*

     10.42  Offer Letter between the registrant and Martin A. Kropelnicki, dated
            February  15, 2006  (incorporated  by  reference  to Exhibit 10.1 to
            Amendment  No. 1 to  Current  Report on Form 8-K of the  registrant,
            dated February 22, 2006)*

                                       35


13.  Annual Report to Security Holders:

     13.1   2005 Annual  Report.  Certain  sections of the 2005 Annual Report to
            Stockholders  are  incorporated by reference in this 10-K filing and
            filed  with  this Form  10-K as  Exhibit  13.  This  includes  those
            sections  referred to in Part I, Item 1,  Business;  Part I, Item 2,
            Properties;  Part II, Item 5, Market for Registrant's Common Equity,
            Related   Stockholder  Matters  and  Issuer  Repurchases  of  Equity
            Securities;  Part II, Item 6, Selected Financial Data; Part II, Item
            7, Management's  Discussion and Analysis of Financial  Condition and
            Results  of  Operations;   Part  II,  Item  7A,   Quantitative   and
            Qualitative   Disclosures  About  Market  Risk;  Part  II,  Item  8,
            Financial  Statements and Supplementary  Data; and Item 9A, Controls
            and Procedures

21.  Subsidiaries of the Registrant

23.  Consents of Experts and Counsel

     23.1   Consent of Independent Registered Public Accounting Firm

31.  Certifications pursuant to Section 302 of the Sarbanes-Oxley Act of 2002

     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


*    Management contract or compensatory plan or arrangement

                                       36