Water Code § 8700
ARTICLE 6. Enforcement of Unauthorized Activities and Encroachments
(a) It is unlawful for any person or public agency to interfere with, obstruct the performance, maintenance, or operation of, or otherwise take actions that may adversely affect facilities of the State Plan of Flood Control, designated floodways, or streams that are regulated by the board.
(b) The board, executive officer, department, and local agencies that operate and maintain facilities and works on behalf of the board shall have the authority, as set forth in this article, to take administrative or civil enforcement actions to abate and remedy any interference or potential interference proscribed by subdivision (a).