 The catchment areas are the Brisbane Ranges to Geelong's north-west, and the Otway Ranges to the south-west.The first water supplies to Geelong were from the Stony Creek reservoirs near Steiglitz, but, as of 2010, Geelong, together with Ballarat, consumes about 70% of the Moorabool River's water flow.Sewage from Geelong and district is treated at the Black Rock Treatment Plant at Breamlea and then discharged into Bass Strait.