Enoggera DAM
With the recent rainfall from Ex-Tropical Cyclone Alfred filling the Enoggera Reservoir, several constituents have got in touch with us with questions about Enoggera Dam and how water is released to help mitigate potential flooding.
Enoggera Dam, constructed in 1866, holds the distinction of being Brisbane’s oldest dam. Originally built to supply drinking water to the growing population of Brisbane, today it serves multiple roles, including recreation, flood mitigation, and wildlife habitat.
How the Dam Functions During Increased Rainfall
During periods of increased rainfall, Enoggera Dam plays a critical role in managing local water levels. As heavy rains fill the reservoir, the water level within the dam rises accordingly. When water levels approach capacity, the dam employs mechanisms designed to safely release excess water to prevent overflow and manage flood risks.
Mechanism for Releasing Water
Enoggera Dam has an earth and rockfill embankment, with a puddle clay core and an un-gated spillway. This means when water reaches the level of the spillway, water flows over and into Enoggera Creek downstream.
Enoggera has a two level spillway. In 1976, the concrete spillway was added and the embankment raised for more storage and flood capacity. The lower level contains a rectangular culvert under the concrete crest. When the full supply level is reached, water flows through the culverts and out of the dam. The upper spillway has a concrete ogee crest. During major floods, water will also flow over the upper spillway.
Seqwater have created an explanatory video on how dams like Enoggera work:
Impact on Downstream Creeks
When water is released from Enoggera Dam, it directly enters Enoggera Creek. Depending on the volume of water released, the creek's water levels can rise significantly, potentially causing faster currents and increased water turbulence downstream. Residents living near Enoggera Creek may notice temporarily elevated creek levels and should exercise caution during these events. Brisbane City Council actively monitors these situations and issues appropriate alerts and advisories.
Responsibility and Contact Information
The operation and maintenance of Enoggera Dam are managed by Seqwater, the Queensland Government's bulk water supply authority. Constituents with questions, concerns, or feedback regarding the operation of Enoggera Dam, including water releases and flood management, can contact Seqwater directly:
Seqwater
Phone: 1300 SEQWATER (1300 737 928)
Website: www.seqwater.com.au
For general community safety and flood management inquiries within the local area, constituents are also encouraged to contact the Brisbane City Council.
Registration to receive dam release notifications
By registering for our free dam release notification service, you can select the dams you would like to receive notifications about. Simply complete the registration form online and accept the terms and conditions of using the service.