Exhibit 99.1

NEWS RELEASE

		CALIFORNIA WATER SERVICE GROUP

		1720 North First Street		October 28, 2009
		San Jose, CA 95112-4598		For Immediate Release
Contact:		Marty Kropelnicki (408) 367-8200 (analysts)
		Shannon Dean (310) 257-1435 (media)

CALIFORNIA WATER SERVICE GROUP ANNOUNCES RESULTS FOR
3^RDQUARTER 2009

     SAN JOSE, CA — California Water Service Group (NYSE : CWT) today announced net income of $19.6 million and earnings per share of $0.94 for the third quarter of 2009, compared to net income of $22.2 million and earnings per share of $1.06 in the third quarter of 2008.

     Revenues increased by $7.5 million, or 6%, to $139.2 million, with rate increases adding $12.5 million and water usage by new customers adding $3.3 million. A decrease in water usage by existing customers and other charges reduced revenue by $8.3 million.

     Total operating expenses for the third quarter of 2009 increased by $10.1 million, or 10%, to $115.1 million. Water production costs increased by $2.4 million, or 5%, due to higher power costs and wholesale water rates. Administrative costs increased $4.1 million, or 27%, due to increased pension & benefits costs, and increased legal costs. Other operations expenses increased by $1.7 million to $14.6 million as a result of higher costs for pumping and distributing water.

     Maintenance expense increased by 15% to $4.4 million as a result of additional water main repairs. Depreciation expense increased by 11% to $10.3 million as a result of

increases in capital expenditures. Taxes other than income increased $0.4 million to $4.4 million, primarily due to property tax increases.

     Other income, net of income taxes, added $1.0 million of net income for the quarter, while interest expense increased by 33% to $5.5 million due to the new debt offering in April 2009.

     For the twelve months ended September 30, 2009, net income was $41.4 million and diluted earnings per share were $1.99, compared to net income of $40.5 million and diluted earnings per share of $1.94 for the same period last year. Revenues for the trailing twelve months were $443 million, compared to $396 million for the same period in the prior year.

     “During the quarter, the Company filed its 2009 General Rate Case for all 24 California districts and corporate costs,” said President and Chief Executive Officer Peter C. Nelson. “This is significant because we are now filing for rate relief in California for all regulated districts and corporate costs at the same time, which will allow for more timely rate relief of prudently incurred costs,” said Nelson.

     “While we cannot predict the outcome of this filing, the rate case was filed on time and is currently proceeding on schedule,” Nelson said.

     Other Information

     All stockholders and interested investors are invited to listen to the 2009 third quarter conference call on October 29, 2009, at 11:00 a.m. (EST), by dialing 1-866-814-8476 and keying in ID# 1399873. A replay of the call will be available from 2:00 p.m. (EST) October 29, 2009, through December 28, 2009, at 1-888-266-2081, ID# 1399873. The call, which will be hosted by President and CEO, Peter Nelson and Vice President and Chief Financial Officer, Martin A. Kropelnicki, will also be webcast under the investor relations tab at www.calwatergroup.com.

     California Water Service Group is the parent company of California Water Service Company, Washington Water Service Company, New Mexico Water Service Company, Hawaii Water Service Company, Inc., CWS Utility Services, and HWS Utility Services. Together these companies provide regulated and non-regulated water service to nearly 2 million people in California, Washington, New Mexico, and Hawaii. Group’s common stock trades on the New York Stock Exchange under the symbol “CWT”.

     This news release contains forward-looking statements within the meaning established by the Private Securities Litigation Reform Act of 1995 (“Act”). The forward-looking statements are intended to qualify under provisions of the federal securities laws for “safe harbor” treatment established by the Act. Forward-looking statements are based on currently available information, expectations, estimates, assumptions and projections, and management’s judgment about the Company, the water utility industry and general economic conditions. Such words as expects, intends, plans, believes, estimates, assumes, anticipates, projects, predicts, forecasts or variations of such words or similar expressions are intended to identify forward-looking statements. The forward-looking statements are not guarantees of future performance. They are subject to uncertainty and changes in circumstances. Actual results may vary materially from what is contained in a forward-looking statement. Factors that may cause a result different than expected or anticipated include, but are not limited to: governmental and regulatory commissions’ decisions; changes in regulatory commissions’ policies and procedures; the timeliness of regulatory commissions’ actions concerning rate relief; new legislation; electric power interruptions; increases in suppliers’ prices and the availability of supplies including water and power; fluctuations in interest rates; changes in environmental compliance and water quality requirements; acquisitions and our ability to successfully integrate acquired companies; the ability to successfully implement business plans; changes in customer water use patterns; the impact of weather on water sales and operating results; access to sufficient capital on satisfactory terms; civil disturbances or terrorist threats or acts, or apprehension about the possible future occurrences of acts of this type; the involvement of the United States in war or other hostilities; restrictive covenants in or changes to the credit ratings on our current or future debt that could increase our financing costs or affect our ability to borrow, make payments on debt or pay dividends; and, other risks and unforeseen events. When considering forward-looking statements, you should keep in mind the cautionary statements included in this paragraph, as well as the annual 10-K, Quarterly 10-Q, and other reports filed from time-to-time with the Securities and Exchange Commission (SEC). The Company assumes no obligation to provide public updates of forward-looking statements.

     Additional information is available at our Web site at www.calwatergroup.com.

     Attachments (2).

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CALIFORNIA WATER SERVICE GROUP
CONDENSED CONSOLIDATED BALANCE SHEETS

Unaudited
(In thousands, except per share data)

		September 30,				December 31,
		2009				2008
ASSETS
Utility plant:
Utility plant		$	1,676,287			$	1,583,079
Less accumulated depreciation and amortization			(501,704	)			(470,712	)
Net utility plant			1,174,583				1,112,367
Current assets:
Cash and cash equivalents			47,581				13,869
Receivables:
Customers			31,722				22,786
Regulatory balancing accounts			15,592				4,629
Other			10,752				7,442
Unbilled revenue			21,352				13,112
Materials and supplies at average cost			5,457				5,070
Taxes, prepaid expenses and other assets			7,922				12,890
Total current assets			140,378				79,798
Other assets:
Regulatory assets			201,442				198,293
Goodwill			2,615				3,906
Other assets			30,455				23,743
Total other assets			234,513				225,942
		$	1,549,474			$	1,418,107
CAPITALIZATION AND LIABILITIES
Capitalization:
Common stock, $.01 par value		$	207			$	207
Additional paid-in capital			214,715				213,922
Retained earnings			204,570				188,820
Total common stockholders’ equity			419,492				402,949
Long-term debt, less current maturities			373,541				287,498
Total capitalization			793,033				690,447
Current liabilities:
Current maturities of long-term debt			12,424				2,818
Short-term borrowings			12,000				40,000
Accounts payable:
Trade and other			46,894				39,187
Regulatory balancing accounts			7,486				2,585
Accrued interest			9,096				3,295
Accrued expenses and other liabilities			42,938				35,311
Total current liabilities			130,838				123,196
Unamortized investment tax credits			2,392				2,392
Deferred income taxes, net			83,512				72,344
Pension and postretirement benefits other than pensions			152,467				152,685
Regulatory and other liabilities			83,357				83,312
Advances for construction			182,763				176,163
Contributions in aid of construction			121,112				117,568
Commitments and contingencies			—				—
		$	1,549,474			$	1,418,107

CALIFORNIA WATER SERVICE GROUP
CONDENSED CONSOLIDATED STATEMENTS OF INCOME

Unaudited
(In thousands, except per share data)

		September 30,				September 30,
For the three months ended		2009				2008
Operating revenue		$	139,167			$	131,702
Operating expenses:
Operations:
Water production costs			48,898				46,455
Administrative and general			19,084				14,995
Other operations			14,639				12,935
Maintenance			4,405				3,824
Depreciation and amortization			10,259				9,281
Income taxes			13,417				13,510
Property and other taxes			4,371				3,940
Total operating expenses			115,073				104,940
Net operating income			24,094				26,762
Other income and expenses:
Non-regulated revenue			5,194				3,805
Non-regulated expenses, net			(3,464	)			(4,501	)
Gain on sale of non-utility property			—				—
Income taxes (expense) benefit on other income and expenses			(702	)			288
Net other income and expenses			1,028				(408	)
Interest expense:
Interest expense			6,480				5,233
Less: capitalized interest			(950	)			(1,065	)
Net interest expense			5,530				4,168
Net income		$	19,592			$	22,186
Earnings per share
Basic		$	0.94			$	1.06
Diluted		$	0.94			$	1.06
Weighted average shares outstanding
Basic			20,745				20,717
Diluted			20,767				20,740
Dividends declared per share of common stock		$	0.2950			$	0.2925

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

		September 30,				September 30,
For the nine months ended		2009				2008
Operating revenue		$	342,447			$	310,204
Operating expenses:
Operations:
Water production costs			119,468				112,162
Administrative and general			57,331				42,248
Other operations			41,425				37,766
Maintenance			13,352				12,884
Depreciation and amortization			30,739				27,779
Income taxes			21,438				20,127
Property and other taxes			12,371				11,163
Total operating expenses			296,124				264,129
Net operating income			46,323				46,075
Other income and expenses:
Non-regulated revenue			11,173				9,452
Non-regulated expenses, net			(6,826	)			(9,715	)
Gain on sale of non-utility property			675				7
Income taxes (expense) benefit on other income and expenses			(2,032	)			118
Net other income and expense			2,990				(138	)
Interest expense:
Interest expense			17,480				15,405
Less: capitalized interest			(2,270	)			(1,955	)
Net interest expense			15,210				13,450
Net income		$	34,103			$	32,487
Earnings per share
Basic		$	1.64			$	1.55
Diluted		$	1.64			$	1.55
Weighted average shares outstanding
Basic			20,740				20,707
Diluted			20,765				20,731
Dividends declared per share of common stock		$	0.8850			$	0.8775