As communities begin to recover from the devastating effects of Hurricane Sandy, HUD has determined that it is important to recognize lessons learned to employ mitigation actions that ensure that structures located in floodplains are built or rebuilt stronger, safer, and less vulnerable to future flooding events. As a result, this proposed rule would require, as part of the decisionmaking process established to ensure compliance with Executive Order 11988 (Floodplain Management) that new construction or substantial improvement in a floodplain be elevated or floodproofed to a level above the base flood elevation of the Federal Emergency Management Agency's best available data. This rule also proposes to revise a categorical exclusion available when HUD performs the environmental review by making it consistent with changes to a similar categorical exclusion that is available to HUD grantees or other responsible entities when they perform the environmental review.