Exhibit 99.1

		1720 North First Street
		San Jose, CA 95112-4598		July 30, 2008
				For Immediate Release
Contact:		Marty Kropelnicki (408) 367-8200 (analysts)
		Shannon Dean (310) 257-1435 (media)

CAL WATER ANNOUNCES RESULTS FOR THE 2ND QUARTER OF 2008

     SAN JOSE, CA — California Water Service Group (NYSE : CWT) today announced net income of $10.1 million, up 31% from $7.7 million in the second quarter of 2007, and earnings per common share of $0.48, an increase of 30% over $0.37 in the same period last year.

     Revenues increased by $9.8 million, or 10%, to $105.6 million, with rate increases adding $6.0 million, sales to existing customers adding $3.6 million, and water usage by new customers adding $0.2 million.

     Total operating expenses for the second quarter of 2008 increased by $6.7 million to $91.1 million. Water production costs increased by $3.1 million due to water usage being higher compared to the same period last year. Administrative and general and other operations costs increased $1.3 million, due primarily to increases in outside water quality laboratory fees, purchases of

chemicals and filters, conservation program costs, and uncollectable accounts.

     Fewer water system repairs resulted in a $0.3 million decrease in maintenance expense, which was $4.9 million for the quarter. Depreciation expense increased $0.9 million to $9.3 million as a result of increases in 2007 capital expenditures. Taxes other than income remained the same as last year.

     Other income decreased by $0.5 million to $0.4 million, declining as a result of mark-to-market adjustments associated with the market value of assets in the company’s non-qualified retirement plans and a decrease in interest income.

     For the twelve months ended June 30, 2008, net income was $32.2 million and dilutive earnings per share were $1.55, compared to net income of $28.3 million and dilutive earnings per share of $1.41 for the same period in the prior year. Revenues for the trailing twelve months were $378.2 million, compared to $355.8 million for the same period last year.

     “In the second quarter, we continued to work diligently with the California Public Utilities Commission (CPUC) on implementation of its Water Action Plan. As the quarter ended, several key regulatory decisions became effective, including one establishing a water revenue

adjustment mechanism (WRAM) and modified cost balancing account (MCBA), and another authorizing rate increases throughout California to recover prudently-incurred costs,” said President and Chief Executive Officer Peter C. Nelson.

     “Overall it was a busy quarter, but the changes approved by the CPUC allow us to ramp up our water efficiency and conservation efforts, which we believe is critical given the current water issues in California,” Nelson said.

     Rate-Related Matters

     As a result of a decision issued by the CPUC in February 2008 (D.08-02-036), three significant changes occurred on July 1, 2008: a WRAM became effective, decoupling water sales from revenues; conservation rates (also known as tiered or increasing block rates) were established in most California districts to reward residential customers for conservation efforts; and an MCBA was instituted to track cost changes, including supply mix variations, for future recovery or refund in rates.

     Also effective on July 1, the CPUC approved incremental or step increases totaling $1.1 million for four California districts.

     Most recently, on July 10, 2008, the CPUC approved a settlement between the CPUC’s Division of Ratepayer Advocates and Cal Water, authorizing rate increases

totaling $33.4 million for districts in Chico, East Los Angeles, Livermore, Los Altos, Mid-Peninsula (San Carlos and San Mateo), Salinas, Stockton, and Visalia.

     The decision also authorized Cal Water to request recovery in the remaining 16 districts for company-wide cost increases, including those related to water quality, engineering, and accounting, as well as increases in administrative expenses such as health care. $13.7 million in annual cost recovery has been requested and is now reflected in rates.

     Acquisitions and New Business

     In the second quarter of 2008, Hawaii Water Service Company (Hawaii Water) received approval from the Hawaii Public Utilities Commission (HPUC) to acquire a wastewater system serving approximately 800 customers in the community of Pukalani on Maui. Hawaii Water also signed an agreement to purchase a water and wastewater system serving approximately 250 customers in Kukio on the Big Island of Hawaii, which is pending HPUC approval. Additionally, in California, the company entered into an agreement to acquire Skyline County Water District, a 465-connection system adjacent to Cal Water’s Bear Gulch District, which is now pending CPUC approval.

     Other Information

     All stockholders and interested investors are invited to listen to the 2008 second quarter conference call on July 31, 2008, at 11:00 a.m. (EST), by dialing 1-866-837-9789 and keying in ID# 1253334. A replay of the call will be available from 2:00 p.m. (EST) July 31, 2008, through September 29, 2008, at 888-266-2081, ID# 1253334. 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 communities. 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,

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

     Attachments (2).

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Source: California Water Service Group

CALIFORNIA WATER SERVICE GROUP
CONDENSED CONSOLIDATED BALANCE SHEETS
Unaudited

(In thousands, except per share data)		June 30				December 31
		2008				2007
ASSETS
Utility plant:
Utility plant		$	1,503,926			$	1,447,047
Less accumulated depreciation and amortization			(455,862	)			(436,851	)
Net utility plant			1,048,064				1,010,196
Current assets:
Cash and cash equivalents			6,129				6,734
Receivables
Customers			24,195				18,600
Other			4,771				8,617
Unbilled revenue			16,948				12,911
Materials and supplies at average cost			4,671				4,744
Taxes, prepaid expense, and other assets			12,367				8,369
Total current assets			69,081				59,975
Other assets:
Regulatory assets			90,894				90,908
Other assets			23,789				23,420
Total other assets			114,683				114,328
		$	1,231,828			$	1,184,499
CAPITALIZATION AND LIABILITIES
Capitalization:
Common stock, $.01 par value		$	207			$	207
Additional paid-in capital			213,462				211,885
Retained earnings			171,728				173,617
Total common stockholders’ equity			385,397				385,709
Preferred stock			3,475				3,475
Long-term debt, less current maturities			288,281				289,220
Total capitalization			677,153				678,404
Current liabilities:
Current maturities of long-term debt			2,701				2,701
Short-term borrowings			23,000				—
Accounts payable			46,925				36,694
Accrued expenses and other liabilities			40,251				30,258
Total current liabilities			112,877				69,653
Unamortized investment tax credits			2,467				2,467
Deferred income taxes, net			67,536				69,712
Pension and postretirement benefits other than pensions			39,747				39,444
Regulatory and other liabilities			40,235				38,783
Advances for construction			173,221				168,024
Contributions in aid of construction			118,592				118,012
Commitments and contingencies
		$	1,231,828			$	1,184,499

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

For the Three-Months ended:

		June 30,				June 30,
		2008				2007
Operating revenue		$	105,581			$	95,782
Operating expenses:
Water production costs			40,349				37,271
Administrative and General			13,835				14,264
Other operations			12,766				11,010
Maintenance			4,947				5,241
Depreciation and amortization			9,276				8,380
Income taxes			6,442				4,792
Property and other taxes			3,484				3,435
Total operating expenses			91,099				84,393
Net operating income			14,482				11,389
Other income and expenses:
Non-regulated revenue			1,696				3,423
Non-regulated expenses			(1,132	)			(1,966	)
Gain on sale of non-utility property			7				(83	)
Less: income taxes on other income and expenses			(219	)			(560	)
			352				814
Interest expense:
Interest Expense			5,157				4,926
Less: capitalized interest			(439	)			(450	)
Net interest expense			4,718				4,476
Net income		$	10,116			$	7,727
Earnings per share
Basic		$	0.48			$	0.37
Diluted		$	0.48			$	0.37
Weighted average shares outstanding
Basic			20,717				20,666
Diluted			20,741				20,690
Dividends per share of common stock		$	0.2925			$	0.2900

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

For the Six-Months ended:

		June 30,				June 30,
		2008				2007
Operating revenue		$	178,502			$	167,352
Operating expenses:
Water production costs			65,707				63,084
Admistrative and General			27,253				26,835
Other operations			24,831				22,095
Maintenance			9,060				9,750
Depreciation and amortization			18,498				16,781
Income taxes			6,616				5,336
Property and other taxes			7,223				6,840
Total operating expenses			159,188				150,721
Net operating income			19,314				16,631
Other income and expenses:
Non-regulated revenue			4,601				6,465
Non-regulated expenses			(4,168	)			(3,717	)
Gain on sale of non-utility property			7				(83	)
Less: income taxes on other income and expenses			(170	)			(1,086	)
			270				1,579
Interest expense:
Interest Expense			10,171				9,852
Less: capitalized interest			(889	)			(950	)
Net interest expense			9,282				8,902
Net income		$	10,302			$	9,308
Earnings per share
Basic		$	0.49			$	0.45
Diluted		$	0.49			$	0.45
Weighted average shares outstanding
Basic			20,702				20,663
Diluted			20,726				20,687
Dividends per share of common stock		$	0.5850			$	0.5800