Preliminary designs for the bridge showed it terminating on Columbia Island, which necessitated expansion of Columbia Island. The United States Army Corps of Engineers already planned to dredge the Potomac River and enlarge Columbia Island, so on April 1, Secretary of War John W. Weeks ordered the expenditure of $114,500 to dredge the river between the Highway Bridge and the Lincoln memorial. The dredged material was to be dumped on Columbia Island. To ensure the island could support the bridge, the Corps also planned to construct a levee around the island.