Cataract Dam facts for kids
Quick facts for kids Cataract Dam |
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Cataract Dam wall
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 Location in New South Wales
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| Country | Australia |
| Location | Cataract Road, Cataract, New South Wales |
| Coordinates | 34°15′56″S 150°48′11″E / 34.26556°S 150.80306°E |
| Purpose | Potable water supply |
| Status | Operational |
| Construction began | 1902 |
| Opening date | 1907 |
| Construction cost | A£329,136 |
| Operator(s) | Sydney Catchment Authority |
| Dam and spillways | |
| Type of dam | Gravity dam |
| Impounds | Cataract River |
| Height | 56 m (184 ft) |
| Length | 247 m (810 ft) |
| Dam volume | 112×103 m3 (4.0×106 cu ft) |
| Spillway type | Uncontrolled |
| Spillway capacity | 1,550 m3/s (55,000 cu ft/s) |
| Reservoir | |
| Total capacity | 94,300 ML (2.07×1010 imp gal; 2.49×1010 US gal) |
| Catchment area | 130 km2 (50 sq mi) |
| Surface area | 8,500 ha (21,000 acres) |
| Website at Sydney Catchment Authority |
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| Official name | Cataract Dam |
| Type | State heritage (built) |
| Criteria | a., b., c., d., e., f., g. |
| Designated | 18 November 1999 |
| Reference no. | 01359 |
| Type | Water Supply Reservoir/ Dam |
| Category | Utilities - Water |
| Builders | Department of Public Works |
The Cataract Dam is a historic dam in Cataract, Australia. It supplies drinking water to the Macarthur and Illawarra areas, the Wollondilly Shire, and the city of Sydney. It is one of four dams that are part of the Upper Nepean Scheme, which helps manage water for the region.
The dam was finished in 1907. Ernest Macartney de Burgh oversaw its construction. Today, Water NSW, a government agency, owns and operates the dam. Because of its importance, the dam was added to the New South Wales State Heritage Register in 1999.
Contents
How the Dam is Built
The Cataract Dam is a type of dam called a gravity dam. This means it uses its own heavy weight to hold back the water. It has a special overflow area, called a spillway, on its left side.
The dam stands 56 metres (184 ft) (about 184 feet) tall and is 247 metres (810 ft) (about 810 feet) long. It can hold a huge amount of water: 94,300 megalitres (3,330×106 cu ft) (about 25 billion US gallons).
Cataract Dam was the very first dam built for the Upper Nepean Scheme. It was also the first dam in Australia to use special pre-made concrete blocks for its front (upstream) face. The back (downstream) face was made from a lot of poured basalt concrete.
Workers found good rock for the dam at Sherbrooke, near Bulli Pass. To move the basalt rock from the quarry to the dam site, they built a narrow steam tramway, 8.8 kilometres (5.5 mi) (about 5.5 miles) long.
The dam is built using large cyclopean masonry blocks. These are huge sandstone blocks, weighing between 2 to 4.5 long tons (2.03 to 4.57 t; 2.24 to 5.04 short tons) tons each. They were dug up right at the dam site and set in cement. The spaces between the blocks were filled with basalt or sandstone concrete.
Water used to flow out of the dam through two large pipes, 122-centimetre (48 in) (48 inches) wide. A special valve, called a Larner Johnson needle valve, controlled this flow. The dam wall was also decorated. The top of the front wall had a castle-like design made of sandstone blocks. The top of the back wall had a decorative concrete edge.
In the middle of the dam stands the valve house. This building is made of sandstone blocks and has a steep slate roof with fancy decorations.
Construction of the dam started in 1902 and finished in 1907. The spillway was made wider in 1915 to handle more water. E. M. de Burgh was the main engineer for the project from 1904.
Dam History
The Upper Nepean Scheme began in 1880. This was because the old water system for Sydney, called the Botany Swamps scheme, wasn't big enough anymore. The Nepean project involved building a weir (a small dam) across the Nepean River. This weir would send water from the Cataract, Cordeaux, Avon, and Nepean rivers to the Prospect Reservoir.
The Water Supply and Sewerage Branch of the New South Wales Public Works Department designed and built Cataract Dam. Many engineers worked on it, including Cecil Darley, Leslie Wade, Henry Dare, and Ernest M. de Burgh. The dam's success shows how skilled these engineers were.
An early idea for the dam by Thomas Keele led to some problems with costs. This was even made fun of in a poem by Banjo Paterson called The Dam that Keele Built.
Appin and the Dam's Surroundings
The town of Appin, near the dam, was named by Governor Macquarie in 1810. He thought the area looked like his home in Scotland. Early settlers in Appin grew wheat, corn, and barley to feed Sydney.
One of the oldest buildings in Appin is the Anglican school, built around 1815. Early land grants in the area helped develop farming. A Sydney businessman, Thomas Rose, built an important dam for water in 1824. He also built a large stone windmill in 1836, which is now a water tank.
The area around the dam has many historic properties. These include Mount Gilead, Beulan, Meadowvale, and Kildare. Many small farms were later combined into larger properties.
Appin also has two strong stone churches, St. Bede's Roman Catholic and St. Mark's Anglican, both built around 1840–41. In 1825, Appin had a population of 562 people, mostly farmers.
The Upper Nepean Water Scheme
The Upper Nepean Scheme started in 1880 because Sydney needed more water. The scheme was designed to supply water for up to 540,000 people. In 1902, a bad drought caused water levels in Prospect Reservoir to drop very low. This led to a serious water shortage for Sydney's 523,000 residents.
Because of this crisis, the NSW Government started a special investigation in March 1902. They recommended building a large storage dam where Cataract Creek meets the Cataract River. The plan was for a dam that could hold about 7 billion gallons of water.
The law to build the dam was passed in 1902. By June 1903, the area for the dam was cleared, and digging for the foundations began. The dam was completed in late 1907, costing about $658,272. It was officially handed over on June 10, 1908.
The reservoir filled completely for the first time on January 13, 1911. It became clear that the spillway needed to be wider to prevent floods from going over the dam wall. This work was finished in 1915.
In 2016, the government allowed a coal mine, South 32 Dendrobium, to operate in the Metropolitan Special Area. This area was created to protect the water quality of Cataract, Cordeaux, Avon, and Nepean Reservoirs.
Dam Features and Buildings
The Cataract Dam is made of large sandstone blocks, weighing between 1.8 to 4.1 tonnes; 1.8 to 4.0 long tons (2 to 4.5 short tons) tons. These blocks were quarried (dug up) at the dam site and set in cement. The front face of the dam has special pre-made basalt concrete blocks. The back face is also made of basalt concrete, being 2 metres (6 ft) thick at the bottom and 1 metre (3 ft) thick at the top.
Two large pipes, 122-centimetre (48 in) (122 cm) wide, pass through the dam to release water into the river. Today, the water flow is controlled by an AGE Ring Faulkner valve.
The dam wall has decorative features. The top of the front wall looks like a castle, with sandstone blocks. The top of the back wall has a decorative concrete edge. The valve house, near the center of the dam, is made of sandstone and has a slate roof.
Here are some facts about Cataract Dam:
- Built: 1902 - 1907
- Material in wall and spillway: 113,154 cubic metres (148,000 cu yd) (about 113,000 cubic meters)
- Length of dam: 247 metres (811 ft) (about 247 meters)
- Length of spillway: 209 metres (684.5 ft) (about 209 meters)
- Width at base: 48 metres (156 ft) (about 47.5 meters)
- Width at top: 5 metres (16.5 ft) (about 5 meters)
- Deepest water: 46 metres (150 ft) (about 45.7 meters)
- Full water level: 290 metres (950 ft) above sea level
- Lake area: 851 hectares (2,104 acres) (about 851 hectares)
- Capacity: 94,300 gigalitres; 24,911 billion US gallons (20,743×109 imp gal) (about 94,300 megalitres)
Water from Cataract Dam flows into the Cataract River. Then, another small dam (weir) diverts it into the Cataract Tunnel, which is 2 miles (3.2 km) (about 3.2 km) long. This tunnel carries the water to Prospect Reservoir.
Near the dam wall, there's the Cataract Dam Official Quarters. This house, built in 1910, was for Water Board staff. It's a beautiful single-story house made of sandstone, with a veranda and fancy timber posts. It used to have offices and bedrooms and is now used by Water NSW and can be rented for holidays. The gardens around it are well-kept, with lawns and garden beds. There's also a sandstone garage, now a conference hall, and two sandstone amenity blocks.
Three more sandstone cottages are located east of the dam. These were for staff and were built with similar designs. There's also a brick house from the 1950s/60s.
The public area around the dam is a great place to visit. It has picnic areas, shelters, fireplaces, and a playground. The gardens are attractive and still show parts of their original design from the early 1900s.
Dam Condition and Changes
As of 2009, the dam was in good condition. Most of its original staff cottages and the Official Residence are still there. While some of the original garden details have changed, the overall design is still visible.
Some changes have been made to the dam over the years:
- 1940: Torpedo Booms (barriers) were put in.
- 1962: The Upper Valve House was rebuilt.
- 1987: The dam wall was made stronger with special anchors.
- The original Larner Johnson Needle Valve was replaced with a newer AGE Ring Faulkner Valve.
- The spillway and dam were updated for safety in 1981 and 1989.
Cataract Dam is located in the Wollondilly and Wollongong local government areas.
Why Cataract Dam is Important
Cataract Dam is a very important part of Australia's history and engineering. It was the first of four major dams built for the Upper Nepean Water Supply Scheme, which is one of Australia's most important public water systems.
Engineers from the Public Works Department, including L.A.B. Wade and E.M. De Burgh, designed Cataract Dam. It was a big step in providing a reliable water supply for Sydney and nearby areas. When it was built, Cataract Dam was the largest dam in New South Wales and was considered a major engineering achievement. It still provides a lot of water for Sydney today.
The dam itself is a beautiful structure with a strong Tudor style look. This design fits well with the dam's large size and its natural surroundings.
The Cataract Dam site also includes other important buildings:
- Sandstone Cottages: These handsome cottages were built for the dam's staff and show how homes were built in that era.
- Official Quarters (The Manor): This is a great example of a Federation Queen Anne style house. It was used by senior engineers and even the Governor of NSW when the dam opened.
- Gardens: The dam's surroundings still have parts of its early 20th-century gardens. These show a high level of landscape design. Some garden features, like the grotto shelter and ornamental follies, are rare and show excellent craftsmanship. The large public parklands around the dam are very popular. The area around the dam wall, with its engineering structures, the lake, and the gorge, creates a beautiful cultural landscape.
Cataract Dam was listed on the New South Wales State Heritage Register in 1999 because of its historical, engineering, and aesthetic importance.
Historical Significance
Cataract Dam was the first of the major water supply dams built in New South Wales. Its construction introduced new methods of dam building that were then used for other dams in NSW until the late 1940s.
For many years, until the Cordeaux Dam was finished in 1926, Cataract Dam was the main source of water for Sydney. By providing a secure water supply, the dam helped Sydney grow and develop in the early 20th century.
Engineering and Design Achievements
The dam's wall is a great example of engineering and beauty. Its tall, straight wall fits perfectly within the Cataract River gorge. The design of the crest house and other features was done by the Government's Architect Branch, showing the style of the time.
The area around the dam, including the "Manor" (Official Quarters) and its gardens, shows careful planning and design. The use of different trees and the layout of paths and steps create a park-like setting.
The dam's unique "cyclopean masonry" construction (using huge, irregular stones) was a new method for its time. The lower valve house and screen tower were also early and unique structures. The construction used advanced technology for its time, like cableways and electrically powered equipment, which was rare in NSW then.
The building of Cataract Dam was also unique because it was the subject of several official investigations (Royal Commissions) into its cost. This likely influenced how later dams were built.
The dam is considered one of the most decorative dams in NSW, with its beautiful stone finishes and the design of its crest house. The construction site was also the first large temporary camp built for a dam project in NSW.
Engineering Heritage
The Cataract Dam is recognized as a National Engineering Landmark by Engineers Australia. This is part of their program to highlight important engineering achievements.
Images for kids
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Cataract Dam - Judge Backhouse in foreground, 22 April 1922
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Cataract Dam in 2010
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Cataract Dam in 2010
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