In March of 1974, Congress authorized the U.S. Army Corps of Engineers (USACE) to design and construct a flood control channel which would contain water flows generated by a 100 year storm event. The channelization and bridge replacement projects cost $63 million in 1974; the four watershed localities paid $12 million, while the Federal government covered the remaining $51 million for this effort.
The USACE Four Mile Run flood control project extends for 2.3 miles from Shirley Highway (I-395) to the stream's confluence with the Potomac River, and includes the replacement of multiple roadway and railroad bridges. The project was completed and dedicated in August 1980.
In order to qualify for the federal assistance, the four watershed jurisdictions were required by Congress to develop and implement a multi-jurisdictional land management program for the watershed. This prerequisite was intended to assure that stormwater runoff from future development in the watershed would not produce stream flows that would impair the effectiveness of the Federal flood control improvements. This marked the first time in history that a basin-wide land planning stipulation was attached to the commitment of Federal funds for a flood control project. This prerequisite has since become a regular feature of subsequent Federal investments of this type.