Woronora Dam facts for kids
Quick facts for kids Woronora Dam |
|
|---|---|
Aerial view of Woronora Dam reservoir
|
|
 Location of the Woronora Dam of the southern boundary of greater Sydney
|
|
| Country | Australia |
| Location | south of Sydney, New South Wales |
| Coordinates | 34°6′40″S 150°56′4″E / 34.11111°S 150.93444°E |
| Status | Operational |
| Construction began | 1927 |
| Opening date | 1941 |
| Construction cost | A$13 million |
| Owner(s) | Sydney Catchment Authority |
| Dam and spillways | |
| Type of dam | Gravity dam |
| Impounds | Woronora River |
| Height | 66 m (217 ft) |
| Length | 390 m (1,280 ft) |
| Dam volume | 285×103 m3 (10.1×106 cu ft) |
| Spillway capacity | 1,470 m3/s (52,000 cu ft/s) |
| Reservoir | |
| Creates | Woronora Dam |
| Total capacity | 71,790 ML (2,535×106 cu ft) |
| Catchment area | 75 km2 (29 sq mi) |
| Surface area | 380 ha (940 acres) |
| Official name | Woronora Dam |
| Type | State heritage (built) |
| Designated | 18 November 1999 |
| Reference no. | 1378 |
| Type | Water Supply Reservoir/ Dam |
| Category | Utilities – Water |
| Builders | Metropolitan Water, Sewerage and Drainage Board of NSW |
The Woronora Dam is a special heritage-listed dam in New South Wales, Australia. It's a type of dam called a gravity dam, which means it stays in place because of its own heavy weight. The dam is built across the Woronora River.
Its main job is to provide drinking water for the southern parts of Sydney and the northern areas of Illawarra. The large lake of water held back by the dam is also called Woronora Dam. Sometimes, people mistakenly call it Lake Woronora.
The dam was designed by G. E. Haskins and built by the Metropolitan Water, Sewerage and Drainage Board of NSW. Construction started in 1927 and finished in 1941. Today, the Sydney Catchment Authority owns and manages the dam. It was added to the New South Wales State Heritage Register in 1999 because of its importance.
In 2009, a mining company received approval to mine for coal near the dam's water source. In 2020, final approval was given for mining tunnels directly under the dam's water storage area.
Contents
Building the Woronora Dam: A Look Back
Why Was Woronora Dam Built?
Water first came to the Sutherland Shire area in 1911 through a pipe from Penshurst Reservoir. Later, in 1920, there was an idea to get water from the Woronora River. This idea was first rejected but then brought back to life five years later.
The plan was to build a dam on the Woronora River. This dam could be made bigger if needed. It was located about 24 kilometres upstream from where the Woronora River joins the Georges River.
How Was the Dam Constructed?
Building the Woronora Dam began in 1927. It was the fifth dam built to help supply water to Sydney. As expected, the dam wall needed to be made larger two years after construction started.
Workers lived in simple homes made of fibrolite. In 1930, the Great Depression caused work on the dam to stop. Many workers had to leave their families to find jobs elsewhere. Some families had worked on other Sydney dams, moving from the Nepean Dam to Woronora, and then to Warragamba Dam.
Work on the dam restarted in late 1931 with special funding. The dam was finally finished in 1941. It cost about A$13 million to build.
Woronora Dam's Role in Sydney's Water Supply
Woronora Dam is unique because it's not connected to Sydney's other main water systems. These include the Upper Nepean Scheme, Warragamba, and Shoalhaven Scheme. The dam was built to add to Sydney's water supply while the much larger Warragamba Dam was being constructed.
After the dam was finished, some of the workers' cottages were kept for maintenance staff. The rest of the Woronora township area was turned into picnic and recreation spots for the public.
Woronora Dam: Design and Location
What Does Woronora Dam Look Like?
The Woronora Dam has a curved shape. It's a mass gravity dam, meaning its huge weight keeps it stable. The dam wall is 66 metres tall and 390 metres long.
The lower parts of the dam are built with massive sandstone blocks. These blocks were dug up right at the construction site. The main wall is made from concrete. Inside the dam, there are two special tunnels called inspection galleries. These allow engineers to check the dam's condition.
How Does the Spillway Work?
The dam has a separate, curvy spillway. A spillway is like a safety valve for the dam. It lets out extra floodwater at a rate of 1,470 cubic metres per second. This water flows through a concrete channel into the river below the dam.
In 1988, the Woronora Dam was updated to meet modern safety rules. This upgrade cost A$2.9 million and added new drainage systems.
Where Does the Dam Get Its Water?
The dam's catchment area is 75 square kilometres. This is the area of land where rainfall collects and flows into the dam. The Sydney Catchment Authority manages this area and the dam's facilities.
There are no towns directly in the catchment area. However, parts of the Princes Highway, Heathcote Road, and the Illawarra railway line pass through it. The nearby urban areas are Sutherland and Campbelltown.
How is Water Treated and Supplied?
Raw water from Woronora Dam is pumped to the Woronora Water Filtration Plant nearby. This plant cleans the water to make it safe for drinking. It's one of nine such plants that supply water to Sydney.
The dam and water plant provide water to areas south of the Georges River. These include Sutherland, Helensburgh, Otford, Stanwell Tops, Lucas Heights, and Bundeena.
Other Uses of the Dam
The Department of Defence uses the Woronora Dam's reservoir for testing. They test their sonar equipment from a pontoon floating in the middle of the lake.
The dam is open for the public to visit. There's a walking trail across the dam wall and a picnic area with a carpark. You can reach the dam by driving seven kilometres along Woronora Dam Road from the Princes Highway.
Woronora Dam in Popular Culture
The building of the Woronora Dam was featured in the comedy drama film Dad Rudd MP. The movie included scenes of the dam's construction. Many workers and their families from the dam site acted as 'extras' in the film.
Why Woronora Dam is a Heritage Site
Woronora Dam was built between 1927 and 1941. It was the last of five important dams built before World War II. These dams made sure Sydney had enough water as the city grew. Woronora Dam specifically helped supply water to the southern suburbs of Sydney.
Its Unique Design and Construction
The dam's design includes special drainage systems and a classical architectural style for its crest and valve houses. These features show how dams were built in the 1930s. The large amount of concrete used in the upper parts of the dam wall was very unusual for its time in New South Wales.
The design of the spillway, with its zig-zag wall and channels, was also a new and important step in dam building technology. Woronora Dam is part of a group of large dams in New South Wales. These dams were built before the Snowy Mountains Scheme and are still mostly complete.
Old Technologies Still Present
The dam still has original water delivery equipment from the Inter-war era. This includes iron pipes, a special roller gate, and other parts. These are rare examples of their kind because of their size and how well they have been kept. The steel pipeline that carries water to Penshurst was also a new construction method for New South Wales.
Remains of the Construction Site
The area around the dam still shows signs of its construction. There are old roads carved into the hillside and places where buildings once stood. These remnants help us understand what it was like to build such a huge project. They show the amazing civil engineering work done back then.
A Place for the Community
The dam is a well-known landmark in the region. Since the 1950s, efforts have been made to make the area beautiful for visitors. The picnic areas are especially popular and have a long history with the Water Board's management. The dam grounds are a special place for local communities to relax and enjoy nature.
Woronora Dam was listed on the New South Wales State Heritage Register in 1999 for many reasons:
- It shows how New South Wales history unfolded. The dam helped the southern suburbs of Sydney grow by providing a reliable water supply from the 1930s. Its long construction time (1927-1941) was affected by the Great Depression. Building the dam was one of the biggest public works projects during that tough time.
- It is linked to important people. The dam's design and construction involved skilled engineers from the Water Board. These included Gerald Haskins, Stanley T. Farnsworth, and Sir William Hudson, who is famous for his work on the Snowy Mountains Hydro-Electricity Scheme.
- It shows great design and technical skill. The dam wall is a beautiful engineering work with its long, curved shape set in the Woronora River valley. The design of the crest house and valve house also shows a grand, monumental style that fits a dam perfectly.
- It has a strong connection with the community. The National Trust of Australia (NSW) sees the dam as an important part of Australia's cultural environment. It has historical, architectural, scientific, and social value. The Heritage Council of N.S.W. also recognizes its importance to the state. Many people in the community remember the construction township, especially during the Great Depression.
- It can teach us more about history. The dam wall is a great example of gravity dam construction from its era. It has features like inspection galleries and drainage systems. The use of a lot of concrete in the upper wall was a big step forward in dam building. The old construction areas can also show us how workers lived and built things back then. The untouched bushland in the catchment area is also valuable for studying nature.
- It has rare or unique features. The way mass concrete was used in the upper dam wall was a first for New South Wales on this scale. The dam's size is also unusual for its main purpose. The zig-zag spillway design is likely unique in New South Wales for its time. The use of a welded steel pipeline to deliver water was also a first. The dam is one of only two in New South Wales with detailed classical architectural features. The crest and valve houses still have original ironwork, showing old water supply technology.
- It represents important characteristics of cultural places. Woronora Dam is a good example of gravity dams built in New South Wales in the early 20th century. Its features include sandstone blocks, concrete, a separate spillway, and well-designed valve houses. The construction methods used, like cableways and temporary camps for workers, also represent practices of that time. The way the land was restored and turned into picnic areas shows how dam sites were beautified. The ongoing maintenance and public access also reflect common practices for dams in New South Wales.
Images for kids
-
Woronora Dam reservoir and surrounding catchment area
-
Woronora Dam at 54% capacity
-
Woronora Dam Spillway
