The original Cotter Dam, a 30 meter concrete gravity dam, was constructed in 1915 (raised in 1951) and served as Canberra's primary water source until the 1960's.
Between 2009 – 2013 construction of an 80 meter high enlarged Cotter Dam occurred 100 meters downstream from the original. This new dam wall increased the holding capacity of the reservoir from 4GL to 76GL. Water sourced from the Cotter Dam must be pumped to the Mt Stromlo Water Treatment Plant via the historic Cotter Pumping Station.
Storage Capacity: 76,200 million litres* fed from a 482 square kilometre catchment area which also contains the Bendora Dam and Corin Dam.
Top water level: 550.8m above sea level
Facts: Cotter Dam is a concrete gravity dam completed in 2013.
The original Cotter Dam was not used for water supply for many years as sufficient water could be obtained from Bendora and Corin Dams which usually have better water quality and do not require pumping. In December 2004 ACTEW brought the original Cotter Dam back into service in response to the ongoing drought.
The enlarged Cotter Dam, completed in 2013, was built as part of a suite of projects to ensure the ACT has a secure water supply. This new dam allows us to better deal with future droughts without having to endure high level water restrictions.