24 C.F.R. § 55.10

(a) When the proposed project includes new construction activities (including grading, clearing, draining, filling, diking, impounding, and related activities for any structure or facilities including the siting of new manufactured housing units) that will have a direct impact to onsite wetlands identified by the process described in § 55.9, compliance with this part requires completion of the 8-step decision making process in § 55.20 to address wetland impacts.

(b) When the proposed project may indirectly affect wetlands by modifying the flow of stormwater, releasing pollutants, or otherwise changing conditions that contribute to wetlands viability, the significance of these impacts must be evaluated and the impacts minimized through best management practices. If the project site includes wetlands that will not be impacted by new construction, HUD strongly encourages measures to preserve such wetlands from future impacts, including by obtaining a restrictive covenant, conservation easement, or other mechanism.

(c) When the proposed project may indirectly affect off-site wetlands, impacts should be minimized to the extent practicable. While this part does not require further decision making to address these effects under the authority of Executive Order 11990, measures to address offsite wetlands impacts may be necessary to comply with related laws and authorities including the Endangered Species Act or to address significant impacts under the National Environmental Policy Act.