Section 404 of the Clean Water Act requires a permit from the U.S. Army Corps of Engineers (USACE) to deposit fill material in so-called "waters of the United States." These 404 permits are required anytime a flood control channel or detention basin is constructed in a water of the United States.
In 2019, the USACE re-issued Regional General Permit 7 (RGP 7). It provides streamlined permitting for fill activities associated with the District's construction program.
The local municipalities who construct and maintain flood control projects expressed a need for timely permit decision and certainty in mitigation requirements. RGP 7 does exactly that.