(a) No money appropriated for flood control projects shall be allocated for the purchase of lands, easements, and rights-of-way necessary for multiple purpose dams or reservoirs constructed by the United States, and authorized by the Legislature prior to January 1, 1987, except the projects on the Fresno and Merced County Stream Groups.
(b) For projects involving dams or reservoirs authorized by the Legislature after January 1, 1987, the state shall pay for the costs of the flood control components of the project as specified in Section 12585.5.