Section 6-501 - Review of building permit applications; design and construction requirements(a).The Mayor shall review all building permit applications for new construction or substantial improvements to determine whether proposed building sites will be reasonably safe from flooding. If a proposed building site is in a location that has flood hazard, the proposed new construction or substantial improvement (including prefabricated homes) must:(1) Be designed (or modified) and anchored to prevent flotation, collapse, or lateral movement of the structure;(2) Use construction materials and utility equipment that are resistant to flood damage; and(3) Use construction methods and practices that will minimize flood damage.(b)(1) The Mayor, pursuant to Title I of the District of Columbia Administrative Procedure Act, approved October 21, 1968 (82 Stat. 1204; D.C. Official Code § 2-501et seq.), may issue rules designating flood hazard areas in the District and requiring flood insurance as a condition of occupancy for the life of a new or substantially improved building in a flood hazard area.(2) For the purposes of this subsection, the term: (A) "Flood hazard area" means an area designated as: (i) A special flood hazard area or other area of flood hazard on the then-current flood insurance rate map for the District of Columbia issued by the Federal Emergency Management Agency; or(ii) An area of flood hazard, as determined by the Mayor by rule.(B) "Substantially improved building" means any building which has undergone any repair, alteration, addition, or improvement, the cost of which equals or exceeds 50% of the market value of the building before the improvement or repair was started.Amended by D.C. Law 24-151,§ 2, 69 DCR 007728, eff. 8/16/2022.May 26, 1976, D.C. Law 1-64, § 2, 22 DCR 7146.