The county shall cooperate or contract with the United States in any matter relating to any project for flood control or navigation in the valleys of the Anacostia River and its tributaries in the county.

Before the county enters into any contract or agreement with the United States and before any plan relating to a flood control or navigation project or the maintenance or operation of a flood control or navigation project is approved, the county shall submit for consideration each contract, agreement, or plan affecting a State road or land in a park or parkway under the jurisdiction of the Commission to: the State Highway Administration; and the Commission. The county may not approve a plan or enter into a contract or an agreement that is inconsistent with: the purposes of the Capper–Cramton Act, Public Law 71–284, 46 Stat. 482; or any agreement between the Commission and the National Capital Planning Commission related to the park and parkway system authorized by that Act.

Except for costs borne by the United States or the State Highway Administration, the county shall pay all costs of a flood control or navigation project from the Stormwater Management Fund. The county shall apply the Fund to the cost of: constructing and relocating all county roads and bridges related to the flood control or navigation project; constructing necessary internal drainage facilities; relocating utility structures; and acquiring land and buildings necessary for the flood control or navigation projects. The county may accept contributions from the United States, the District of Columbia, the State, Montgomery County, any municipal corporation or special taxing district, or any other person if the county determines that the contribution may assist in the construction of any project under this subtitle.

The Commission: may use the lands acquired for flood control or navigation projects for park purposes if the use does not interfere with the construction, maintenance, and operation of the projects; and shall control and operate recreational facilities within the projects.