A county flood control district may not exercise any power or authority granted by this article, nor may it undertake or cooperate in planning, authorizing, constructing, acquiring, extending, improving, maintaining or operating any flood control structures, dam systems or projects on any portion of a watershed supplying water to any dam and reservoir existing within this state having a designed water storage capacity of fifty thousand acre feet or more, or to any existing diversion dam and canal system having facilities within this state designed to divert and carry not less than one thousand cubic feet per second, without first obtaining the written consent of the agency, district, association, company or organization owning or operating or being served by such dam, reservoir, diversion dam or canal system. Such consent, however, is only required from irrigation districts and agricultural improvement districts organized pursuant to the laws of this state and defined under this title, and any other associations or organizations operating such dams, reservoirs, diversion dams and canal systems as part of a federal reclamation project. This section does not prohibit the district from adopting and enforcing such regulations as are duly enacted pursuant to this article.