Cotter Dam

Check out the Cotter Dam spilling for the first time since construction was completed in October 2013!

The original Cotter Dam, a concrete gravity dam, was completed in 1915 built to a height of 18.6m. It was raised from 1949 – 1951 to a height of 28.5m to accommodate a growing population. It served as Canberra's primary water source until the 1960's.

The dam was enlarged again between 2009 – 2013, this time by constructing a new 83 metre high roller compacted concrete dam wall approximately 125 meters downstream from the original dam wall. This new dam wall increased the holding capacity of the reservoir from approximately 4GL to 76GL.

Water sourced from the Cotter Dam is pumped to the Mt Stromlo Water Treatment Plant via the historic Cotter Pumping Station, as the dam is located at a lower altitude than the treatment plant.

Storage Capacity: 76,200 million litres*

Top water level: 550.8m above sea level

The original Cotter Dam was not accessed for water supply for many years as enough water could be obtained from Bendora and Corin Dams. These dams usually have better water quality and water can be fed to the treatment plant using gravity rather than needing to be pumped. In December 2004, the original Cotter Dam was once again accessed 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. The new dam allows us to better deal with future droughts without having to endure high level water restrictions.

Don't forget when visiting the Cotter Dam, do not bring dogs and take your rubbish back with you so that we can keep our drinking water catchments in a pristine condition.

For information about current road access to the dam, please visit the Transport Canberra and City Services website.

*Although the Dam can store a total of 79.4GL, only 76.2GL is accessible due to the location of the intake valve.