Water Code § 8706
ARTICLE 6. Enforcement of Unauthorized Activities and Encroachments
The board may maintain actions in the name of the state to compel by injunction the owner or owners of any bridge, trestle, wire line, viaduct, embankment, or other structure or obstruction that shall be intersected, traversed, or crossed by any bypass, drainage canal, channel, or overflow channel to construct or alter any structure in order to offer a minimum of obstruction to the free flow of water. In the case of existing works, the board may compel the removal or alteration of structures or obstructions that impede the free flow of water.