Enacts new GS 160A­311.1 (Flood control activities under stormwater management programs). States legislative findings. Authorizes a city to purchase property for the purpose of demolishing flood­prone buildings, and to implement flood damage reduction techniques (including specified elements) that improve private property. Requires the city to comply with the policy document approved by the city council when engaging with the above activities. Requires a policy document to establish, at minimum, certain listed policies, including requiring the private property owner's written consent prior to implementation of flood reduction improvements, and may elaborate upon those requirements. Directs existing stormwater advisory committees to review and approve projects that implement flood damage reduction techniques, and to submit an annual report to the city council. Only applies only to cities located in a county that has a population of 275,000 or greater and at least one city with a population of 225,000 or greater.