Avon Dam facts for kids
Quick facts for kids Avon Dam |
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The curved arch dam wall
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 Location of Avon Dam in New South Wales
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| Location | Avon Dam Road, Avon Dam, New South Wales |
| Coordinates | 34°21′09″S 150°38′30″E / 34.3526341175°S 150.6415665100°E |
| Purpose | Potable water supply |
| Status | Operational |
| Construction began | 1921 |
| Opening date | 20 January 1928 |
| Construction cost | A£1,047,000 |
| Operator(s) | Sydney Catchment Authority |
| Dam and spillways | |
| Type of dam | Arch dam |
| Impounds | Avon River |
| Height (foundation) | 22 metres (72 ft) |
| Length | 223 metres (732 ft) |
| Width (crest) | 6 metres (20 ft) |
| Width (base) | 61 metres (200 ft) |
| Reservoir | |
| Creates | Avon Reservoir |
| Total capacity | 146,700 ML (3.23×1010 imp gal; 3.88×1010 US gal) |
| Catchment area | 142 square kilometres (55 sq mi) |
| Surface area | 1,057 hectares (2,610 acres) |
| Maximum water depth | 64 metres (210 ft) |
| Website Avon Dam |
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| Official name | Avon Dam |
| Type | Built |
| Criteria | a., b., c., d., e., f., g. |
| Designated | 18 November 1999 |
| Part of | Utilities - Water group |
| Reference no. | 01358 |
The Avon Dam is a special dam in Avon, New South Wales, Australia. It is listed as a heritage site. This means it is an important historical place. The dam is one of four big structures in the Upper Nepean Scheme. This scheme helps provide drinking water. It supplies water to areas like Macarthur, Illawarra, Wollondilly Shire, and Sydney. The dam was finished in 1927. It was built across the Avon River. Ernest Macartney de Burgh oversaw its construction. Today, the Sydney Catchment Authority manages the dam.
Contents
History of Avon Dam
Why the Dam Was Built
Sydney needed more water as it grew. The first water supply system was not enough. So, in 1880, the Upper Nepean Scheme began. This project aimed to collect water from several rivers. These rivers included the Cataract, Cordeaux, Avon, and Nepean. The water was then sent to the Prospect Reservoir.
However, by 1902, even this new system was not enough. A big drought showed that Sydney still needed more water. Experts recommended building more dams. The first new dam, Cataract Dam, was finished in 1907.
Building More Dams
After 1907, there was not much rain. The Cataract Dam did not fill up until 1911. This showed that even more water storage was needed. The areas around the Cordeaux, Avon, and Nepean rivers were perfect for dams. They had narrow gorges and strong rock foundations. Sandstone was also easy to find nearby. This stone could be used to build the dams.
Work on the Cordeaux Dam started in 1918. At the same time, experts suggested building the Avon and Nepean Dams too.
Avon Dam Construction
In 1921, construction began on the Avon Dam. It was built on the Avon River. This river is a branch of the Upper Nepean. Public Works engineers designed and built the dam. E.M. De Burgh was the chief engineer.
The Avon Dam was built using a method called cyclopean masonry. This means large sandstone blocks were used. They were quarried right from the dam site. Workers fitted these blocks together in a special pattern. They then filled the gaps with sandstone concrete. The dam's front face was covered with basaltic concrete. This made it watertight and strong against waves.
All the concrete was made on site. Special machines crushed rocks and mixed the concrete. Electricity from Port Kembla powered these machines. A 9.6 km (6 mile) road was built from Bargo railway station. This road helped transport all the building materials. Large cranes and cableways were also used. These were all designed and built in Australia.
The area where the water would be stored was cleared. Trees were cut down. Valuable timber was used for railway sleepers and fences. Some special Coachwood timber was found. It was cut at a sawmill built at the dam. This timber was used for buildings and dam forms.
Workers lived near the construction site. Single men stayed in barracks. Married men built temporary homes for their families.
Dam Completion and Use
The Avon Dam was finished in 1927. It officially opened on January 20, 1928. The total cost was about A£1,047,000.
The dam supplied water to Sydney until 1960. That's when the Warragamba Dam was completed. After 1963, Avon Dam's water was mainly used for Wollongong and Port Kembla. A pumping station sends water over to these areas.
In 1973, a tunnel was built between Nepean Dam and Avon Dam. This tunnel allows water to be moved between the two dams. This helps manage the water supply for Sydney, Wollongong, and Sutherland.
About Avon Dam Today
Dam Structure and Features
The Avon Dam was the third and largest of the four dams built for the Upper Nepean area. It has a curved wall. The dam also has a spillway. This is a channel that lets excess water flow out safely. It was cut through a ridge near the dam.
The ends of the dam wall have large, decorative towers. These towers are in an Egyptian style. They even have lotus-shaped columns. The dam has valves at two levels to release water. These valves are used to control the water flow.
Here are some facts about the Avon Dam:
- Water Capacity: 146,700 megalitres (a megalitre is a million litres).
- Deepest Water: 64 metres (210 feet).
- Wall Height: 72 metres (237 feet) from its base.
- Lake Area: 1,057 hectares (2,609 acres) when full.
- Cost to Build: £1,047,000.
- Length at Top: 221 metres (725 feet), including the towers.
- Width at Base: 61 metres (200 feet).
- Width at Top: 6 metres (20 feet).
- Catchment Area: 142 square kilometres (55 sq miles).
Picnic Areas and Gardens
Today, the Avon Dam has a lovely picnic area. It is on the eastern side of the dam. This area used to be where the construction workers lived. It has beautiful gardens with stone walls and green lawns. There are also modern facilities for visitors.
The landscape around the dam is very scenic. Near the dam wall, there are several picnic spots. Some have grotto-like shelters built into the sandstone cliffs. There is also a special garden with palm trees and ornamental pools. These pools are circular and made of cement. They are designed to look like an Egyptian oasis.
The main gardens are a large park-like area. The entrance has stone pillars with "AVON DAM" written in quartz pebbles. There are many different types of trees planted here. These include Swamp Cypress, Hoop Pine, and Flowering Cherry. You can also find rustic picnic structures and a birdbath. Some old cottages are on the ridge above the gardens. These have older trees like Monterey Pine.
Why Avon Dam is Important (Heritage Listing)
The Avon Dam is very important to New South Wales. It is listed on the New South Wales State Heritage Register. This means it is protected for future generations.
Historical Importance
- It was the third and largest of four dams built for the Upper Nepean Water Supply Scheme. This scheme was vital for Sydney's water.
- It helped Sydney grow by providing a reliable water supply.
- The dam's design and building methods show how engineering was done in NSW at that time.
- It was designed by E.M. De Burgh, a leading water supply engineer.
Design and Beauty
- The dam wall is a beautiful curved structure. It looks impressive in the Avon River valley.
- The towers and other buildings at the dam's top have a unique Egyptian style. This design was popular at the time.
- The dam's setting in the valley is very picturesque.
- The picnic grounds and gardens are well-designed. They even include Egyptian-themed elements.
Engineering and Technology
- The dam uses a special building method called cyclopean masonry. This was unique to these metropolitan dams in Australia.
- It has advanced features for its time, like inspection tunnels and drainage systems.
- The machinery and ironwork inside the dam show the water supply technology of that era.
- The spillway channel was one of the largest built in Sydney at the time.
- The special road built to transport materials to the dam was also unique.
Community Value
- The dam and its grounds are recognized by groups like the National Trust of Australia. They are seen as important for their history, beauty, and social value.
- They are also recognized by the Heritage Council of NSW.
Research Potential
- The dam's construction methods offer valuable information for engineers and historians.
- The untouched bushland in the catchment area is good for studying natural ecosystems.
- The old tree plantings show past gardening practices.
See Also
- List of dams in New South Wales
- List of reservoirs and dams in Australia
Images for kids
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The curved arch dam wall
