California Water Service Group Announces Second Quarter Earnings and Teleconference.

SAN JOSE, Calif. -- California Water Service Group (NYSE:CWT) today announced that its second quarter earnings will be released after market-close on Wednesday, August 2, 2006, and its teleconference will be held at 4 p.m. EDT on Thursday, August 3, 2006.

All stockholders and interested investors are invited to listen to the teleconference. The second quarter call may be accessed by dialing 1-866-804-3550 and keying in ID# 932268. The replay of the call will be available from 7:00 p.m. EDT Thursday, August 3 through October 2, 2006, by dialing 888-266-2081 and keying in ID# 932268. The call, which will be hosted by President and CEO Peter C. Nelson and Vice President and Chief Financial Officer Martin A. Kropelnicki, will also be webcast at www.calwatergroup.com.

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, 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 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. The Company assumes no obligation to provide public updates of forward-looking statements.