California Water Service Group is a U.S. water and utilities holding company based in California. The company engages in the production, treatment, storage, distribution, and sale of water for various uses. The firm operates through its subsidiaries, which can be divided between regulated and unregulated businesses. The regulated public utilities subsidiaries operate in California, New Mexico, Washington, and Hawaii. The unregulated subsidiaries provide water utility services to private companies and municipalities. The company derives the majority of its revenue from its operations in California and, overall, from residential customers.