California Code, Water Code - WAT § 12617

The department, upon its own initiative, or when requested in writing by a county, city, state agency or public district, may investigate, conduct surveys and studies, prepare plans and estimates, and render reports concerning control, conservation, protection, and utilization of water resources, including recommendations for plans and projects.  The department may at any time in its discretion enlarge or restrict the scope of any investigation, survey or study as it may determine the public interest requires.