Burrendong Dam

Burrendong Dam is a rock-fill embankment major gated dam with a clay core across the Macquarie River upstream of Wellington in the central west region of New South Wales, Australia. The dam's purpose includes flood mitigation, irrigation, water supply and hydro-electric power generation. The dam impounds Lake Burrendong and is filled by the waters from the Macquarie, and Cudgegong rivers as well as Meroo Creek.

History
The idea of building the dam arose in 1909. However, it was not until 1946 until legislation was passed to construct the dam. Construction commenced in 1950. The town of Mumbil expanded to accommodate the workers building the dam. The dam was completed in April 1965 and water began to flow into it for the first time. It was officially opened on 18 August 1967 by Robert Askin, the Premier of New South Wales. The date was chosen because it was the sesquicentenary of the town of Wellington. In September 1969 the dam was nearly full for the first time.

The village of Burrendong, once a gold-mining area, was flooded by the construction of the dam.

Location and features
The Burrendong Dam is a major dam on the Macquarie River within the Macquarie Valley, approximately 30 km southeast of Wellington. The dam was built by the New South Wales Water Conservation & Irrigation Commission for the purposes of providing flood mitigation, irrigation, and water supply.

The dam wall height is 76 m and is 1116 m long. The water depth is 57 m and at 100% capacity the water level is 344 m AHD. The surface area of the dam is 7200 ha and the catchment area of the dam is 13900 km2. At 100%, Burrendong Dam has a capacity of 1188000 ML. Additionally, the dam has a further flood mitigation capacity of 480000 ML. The spillway on the dam is a gated concrete chute with a release capacity of 13720 m3/s.

Burrendong Dam has three times been recorded at a critically low level of 1.5% in drought. Contrastingly, however, Burrendong has mitigated potentially devastating floods downstream by using its flood capacity and releasing water in accordance with downstream tributary flows, safely reaching 160% of capacity in 1990 and 152.8% in 2010. In January 2020, the lake was again reported to be at 1.6% level.

The A$32 million first phase of a major upgrade began in 2010 and is expected to be completed during 2015. This project will bring the dam up to modern safety standards including the raising of the main dam wall and saddle dam by 1.8 m as well as modifications to the existing spillway, complemented by construction of an auxiliary spillway and fuse plug.

Power generation
A hydro-electric power station generates up to 19 MW of electricity from the flow of the water leaving Burrendong Dam. The average output is 50.9 GWh per annum. The station was completed in August 1996 and was officially opened on 9 February 1999 by the Premier of New South Wales, Bob Carr. At the time, the facility was operated by Power Facilities Pty Limited; and is now managed by AGL Energy.