For all projects funded in accordance with Section 12585.7, the local agency shall receive credit against its share for the value of the lands, easements, and rights-of-way, for lands required for the project, to the extent authorized under federal law. The amount of the credit shall be determined by the department or the Reclamation Board by applying the percentage amount determined in 12585.7 to the actual amount of any credit determined by the United States Army Corps of Engineers.