A number of development proposals were made for Kingman Island throughout the 1960s, although few were adopted. A second concrete span for Benning Bridge was constructed in 1961; the old span now carried eastbound traffic, while the new span carried only westbound traffic. In 1961, the NCPPC proposed filling in of Kingman Lake (about 50 to 60 percent of the lake's total area) and relocating some of the riprap walls to make Islands 3 and 4 part of the mainland and add an additional to Langston Golf Course. This plan was never acted on, and a year later the city proposed turning Kingman Island into a landfill. Two years later, the city proposed closing the first nine holes of Langston Golf Course and building a $10 million public aquarium on the site, but the National Park Service refused to turn over the land to the city. In 1965, the city again asked permission to turn Kingman Island into a landfill. Although this plan was not approved, the city did begin dumping environmental trash (such as grass cuttings, leaves, and tree stumps) on Kingman Island at this time. Four years later, the city proposed closing all of Langston Golf Course and building extensive low-income public housing on the golf course and the rest of Kingman Island.