Exhibit 21

Subsidiaries of the Registrant

Subsidiary Name			State of Incorporation						Business Name
California Water Service Company			California						California Water Service Company
CWS Utility Services			California						CWS Utility Services
New Mexico Water Service Company			New Mexico						New Mexico Water Service Company
Washington Water Service Company			Washington						Washington Water Service Company
Hawaii Water Service Company, Inc.			Hawaii						Hawaii Water Service Company
HWS Utility Services LLC			Hawaii						HWS Utility Services
TWSC, Inc.			Texas						TWSC, Inc.