Chichester Dam
Our first dedicated water source
Chichester Dam was constructed between 1917 and 1926 as the Hunter’s first dedicated drinking water storage system. Chichester Dam is one of the Hunter’s most important freshwater storage facilities contributing about 35% of the Lower Hunter’s potable water supply. Located at the top of the Williams River catchment the dam replaced the Walka Water Works at Maitland, which was unable to meet the water demands of a growing industrial region.
Approximately half the flow from Chichester is supplied to Beresfield, Thornton, Maitland and Cessnock, and the balance blends with Grahamstown/Tomago water in the Newcastle/Lake Macquarie supply.
The catchment for Chichester Dam is largely within the Barrington Tops National Park, which is a declared wilderness area. As a result it is one of the most pristine catchments in Australia with large areas unaffected by human activity.
Chichester Dam statistics
| Catchment area |
197 square kilometres |
| Location |
Located at the top of the Williams River catchment |
| Available Capacity |
21,500 megalitres |
| Surface area of dam |
180 hectares |
| Maximum depth |
37 metres |
| Average daily supply |
90 megalitres |
| Main Embankment Length |
254 metres |
| Wall Height |
43 metres |
| Spillway length |
112 metres |
| Thickness crest |
3.7 metres |
| Thickness bass |
27.4 metres |
| Full Supply Level RL(reduced level) |
156.2 metres ASL (above sea level) |
| Construction |
The wall is 254m long and 43m high, and is a ‘cyclopean’ system of interlocking concrete blocks and large boulders, each approximately 230 cubic metres. The wall is anchored to the bedrock below the wall by 93 stressed tendons. |
Chichester Dam history
Chichester Dam is the oldest water storage facility currently in use within the Hunter and was completed in 1926, although the dam provided its first supply of water to the community in 1923. Before its construction the Hunter relied on water from the Walka Water Works which drew water from the Hunter River near Maitland. Operations at Walka were interrupted by flood and drought, and the water was considered by many to be too ‘hard’.
A more reliable source with a greater capacity to store water was required for both a growing population and the industrial development of the region, which included the Sulphide Corporation at Cockle Creek (1896) and the BHP Steel Mill at Port Waratah (1915). In 1915 the Parliamentary Standing Committee on Public Works advised the NSW Government that a storage dam be built on the Chichester River. Land was gazetted in 1916 and houses for construction workers were erected at Dusodie.
The workers’ health was improved by the provision of a doctor, reticulated water from the Chichester River, hot and cold showers, and a sanitary service. Dwellings were made for families, while single men slept in barracks of about ten beds each. The men erected their own reading room, dance hall and billiards room for Dusodie’s one thousand residents. In the hill above the dam site, a terrace was excavated to allow concrete making plants.
A nearby sawmill supplied timber, which was hauled on wooden tramlines, while a quarry supplied stone and gravel. Two steamdriven cableways, each spanning 335-metres across the gorge, delivered concrete and materials to the workforce. Sand was transported from Newcastle in steam-powered Sentinel trucks, while horse-drawn vehicles carried pipes and other materials.
Upgrades and modifications
As our oldest dam, Chichester has been extensively upgraded and modified to meet changing demands and ensure safety and reliability of supply. Major works include:
- 1965: spillway lowered by 2.75m to increase flood capacity
- 1985: dam post-tensioned with cables, spillway relocated to centre of the dam wall and returned to original height
- 1995: seepage potential reduced under the northern abutment
- 2003: improved drainage system for foundations installed and the left parapet wall raised to prevent overtopping in major flood
How we operate Chichester Dam
The dam holds 21,500 megalitres of water, with an 80 kilometres long gravitation main transporting water from the dam to the major city reservoirs in Maitland, Cessnock and Newcastle.
Water supply from Chichester Dam is used as much as possible due to its reliability and cost. The cost of supplying water from Chichester Dam is the lowest of all Hunter Water’s sources, largely because it feeds into the tank distribution system by gravity. Water from Chichester Dam is dosed with chlorine at the dam and then transported via a gravity pipe to Dungog, where it is further treated at the Dungog water treatment plant
Hunter Water extracts water under the Water Act 1912 and must meet strict conditions outlined in the Water Management Licence which came into effect in 1998.
Hunter Water has increased environmental flow releases from Chichester Dam into the Williams River to manage and minimise environmental impacts. These flows help sustain natural ecosystems along the Chichester River. Hunter Water is committed to managing Chichester Dam for the long-term environmental, social and economic benefit of the people and businesses of the Lower Hunter.
