Gov. Code, § 66474.5

(a) Notwithstanding any other law, after the amendments required by Sections 65302.9 and 65860.1 have become effective, the legislative body of each city and county within the Sacramento-San Joaquin Valley shall deny approval of a tentative map, or a parcel map for which a tentative map was not required, for a subdivision that is located within a flood hazard zone unless the city or county finds, based on substantial evidence in the record, one of the following:

(1) The facilities of the State Plan of Flood Control or other flood management facilities protect the subdivision to the urban level of flood protection in urban and urbanizing areas or the national Federal Emergency Management Agency standard of flood protection in nonurbanized areas.

(2) The city or county has imposed conditions on the subdivision that will protect the project to the urban level of flood protection in urban and urbanizing areas or the national Federal Emergency Management Agency standard of flood protection in nonurbanized areas.

(3) The local flood management agency has made adequate progress on the construction of a flood protection system that will result in flood protection equal to or greater than the urban level of flood protection in urban or urbanizing areas or the national Federal Emergency Management Agency standard of flood protection in nonurbanized areas for property located within a flood hazard zone, intended to be protected by the system. Except as provided in Sections 65962.1, 65962.2, and 65962.4, for urban and urbanizing areas protected by project levees, the urban level of flood protection shall be achieved by 2025.

(4) The property in an undetermined risk area has met the urban level of flood protection based on substantial evidence in the record.

(b) The effective date of amendments referred to in this section shall be the date upon which the statutes of limitation specified in subdivision (c) of Section 65009 have run or, if the amendments and any associated environmental documents are challenged in court, the validity of the amendments and any associated environmental documents has been upheld in a final decision.

(c) This section does not change or diminish existing requirements of local flood plain management laws, ordinances, resolutions, or regulations necessary to local agency participation in the national flood insurance program.