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

The Company and each of its subsidiaries operate in one business segment, the supply and distribution of water, and providing water-related services.