Cal. Water Code § 12670.20

(a) The projects for flood protection and integrated resource management in the Colusa Basin are adopted and authorized substantially in accordance with the “Colusa Basin Water Management Program” dated February 1995 and its final environmental documentation, at an estimated cost to the state of the sum that may be appropriated by the Legislature for state participation, upon the recommendation and advice of the department or the Reclamation Board.
(b) The state, any local public agency, or other entity may cooperate with any federal agency with regard to the planning, design, environmental compliance, financing, and construction of projects authorized in subdivision (a).
(c) No state funds shall be expended for the projects described in subdivision (a) unless both of the following requirements are met:
1. (1) Required environmental documentation has been completed.
2. (2) The Reclamation Board has approved the Colusa Basin Water Management Program and the projects described in subdivision (a).
(d) Except as specified in subdivision (c), for projects authorized in subdivision (a), the state shall pay both of the following:
1. (1) That portion of nonfederal capital costs attributable to flood control required by Section 12585.5, or that may be required by amendment to Chapter 1 (commencing with Section 12570).
2. (2) That portion of nonfederal costs for fish, wildlife, and recreational enhancement features established by Chapter 3.5 (commencing with Section 12840).
(e) If required by the Secretary of the Interior, the Reclamation Board may give assurances satisfactory to the Secretary of the Interior that the local cooperation authorized in subdivision (b) will be furnished by the state in connection with the flood control and fish, wildlife, and recreational enhancement features of the projects described in subdivision (a). Assurances provided pursuant to this subdivision may not be made until the local agency, by binding agreement with the Reclamation Board, has agreed to assume all obligations under Sections 12585 to 12585.5, inclusive, and Section 12642, or that may be required by amendment to Chapter 1 (commencing with Section 12570).
(f) The Colusa Basin Drainage District, or other appropriate local agency, shall establish and maintain a coordinated land use planning and decisionmaking process within the watershed to avoid unmitigated hydraulic impacts.