Water Code § 22655

A district may commence, maintain, intervene in, defend, and compromise actions and proceedings to prevent interference with or diminution of the natural flow of any stream or natural or artificially created subterranean supply of waters which may:

(a) Be used or be useful for any purpose of the district.

(b) Be of common benefit to the land or its inhabitants.

(c) Endanger the inhabitants or the land.