During the 1950s and 1960s, the lake became a dumping ground for rubbish, and there are supposed to be old car bodies and other rubbish at the bottom. These would have leached acids, lead and hydrocarbons into the water over the years. Pollution in the lake renders it unusable as a source of water for the surrounding human population or agriculture. In 1962 the dam wall in Lake Rd was built by the MMBW to form a retarding basin to prevent flooding further down Kooyongkoot Creek, and the Lake Rd Bridge was demolished in 1965.