So.........this is not wiki..........but again wrong.......



5. Inlet Bridge 
Following the disastrous 1881 flood that covered parts of the Mall, the U.S. Corps of Engineers began to dredge the Potomac River in order to improve navigability and reclaim land. The silt and mud placed behind retaining walls created 723.4 acres of new land upon which many of our memorials now stand, including Thomas Jefferson, Lincoln, and World War II. The genesis of Inlet Bridge dates to 1887 when engineers began to install gates at the entrance and exit of a newly formed pond. The gates would allow the pond to fill from the river at high tide, and then empty through the Outlet Bridge into the Washington Channel at low tide. This tidal driven action gives the pond its name, "Tidal Basin." The outflow of water through the channel flushes silt from the marina located there, reducing the need for further dredging. By 1890, the reclaimed land rose above the "high tide" stage and the Tidal Basin gates were completed and tested.