Storage
Hunter Water manages a complex network of dams, storages and pipelines to provide an adequate supply of water to our customers.
To ensure the best quality water is selected from our storages, we use a number of reservoir management processes including:
- selecting from different reservoirs
- selecting from different levels in the storages
- monitoring water quality and analysing trends.
About our storages
Most of our water comes from three main sources – Grahamstown and Chichester Dams and Tomago Sandbeds, with some small contribution being made from Tomaree sandbeds:
- Hunter Water’s largest storage is Grahamstown Dam. Water is collected from rain which falls directly on the dam and its local catchment; and flows transferred from the Williams River. The storage provides around 40% of the average annual supply to the Lower Hunter Region. In 2005, Stage 2 upgrades were completed which raised the spillway level of Grahamstown Dam to 12.8 metres, increasing the capacity of the dam to 190 gigalitres.
- Tomago sandbeds Water is extracted via 160 bores, the majority of which is transferred to Grahamstown Water Treatment Plant. In addition, water is extracted from the north eastern end of the sandbeds to supply water to the Lemon Tree Passage and Karuah areas. The sandbeds provide an integral supplement to existing sources, contributing around 20% of average annual supply, and provide an important drought reserve.
- Chichester Dam located at the head of the Williams River, is a relatively small storage with a capacity of 22,000 Megalitres. The streamflow in the Chichester River, however, is regarded as both large and reliable. Chichester Dam typically supplies around 35% of Hunter Water’s average annual supply.
- The Tomaree Sandbeds supply water to the Port Stephens area. This source typically contributes around 5% of Hunter Waters average annual supply capacity.