Press Release

Cal Water President & CEO to Speak at Water Industry Summit

SAN JOSE, Calif.--(BUSINESS WIRE)--April 7, 2008--California Water Service Group (NYSE:CWT) President and Chief Executive Officer Peter C. Nelson will give a presentation about the company at Janney Montgomery Scott's 2008 Water Industry Summit. The presentation, part of a panel discussion called "Municipal and Private Water Utilities: Meeting the CapEx Challenge," will be held at The Grand Hyatt Hotel in New York City on Tuesday, April 8, 2008, at 9:15 a.m. Eastern time.

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, LLC. Together these companies provide regulated and non-regulated water service to approximately 2 million people in more than 100 California, Washington, New Mexico and Hawaii communities. Group's common stock trades on the New York Stock Exchange under the symbol "CWT." Additional information about the company is available online at www.calwatergroup.com.

    
CONTACT: California Water Service Group Shannon Dean, 310-257-1435 (media) Martin Kropelnicki, 408-367-8200 (analysts) SOURCE: California Water Service Group