The purpose of this subpart is to establish criteria under the provisions of section 1306(c) of the National Flood Insurance Act of 1968, as amended, by which States can obtain approval from the Federal Insurance Administrator to certify that structures are subject to imminent collapse or subsidence as a result of erosion or undermining caused by waves or currents of water exceeding anticipated cyclical levels. The subpart also sets forth the procedures and data requirements to be utilized by those States in certifying structures as subject to imminent collapse. The State certification procedure represents an option to the use of the procedure whereby a structure is condemned by a State or local authority as a prerequisite to consideration for imminent collapse insurance benefits.