Dartmouth Dam facts for kids
Quick facts for kids Dartmouth Dam |
|
|---|---|
Dartmouth Dam wall, pictured in April 2003
|
|
 Location of the Dartmouth Dam in Victoria
|
|
| Country | Australia |
| Location | Victoria |
| Coordinates | 36°33′29″S 147°31′25″E / 36.55806°S 147.52361°E |
| Status | Operational |
| Construction began | 1973 |
| Opening date | 1979 |
| Construction cost | A$139 million |
| Owner(s) | Murray Darling Basin Authority |
| Operator(s) | Goulburn–Murray Water |
| Dam and spillways | |
| Type of dam | Embankment dam |
| Impounds |
|
| Height | 486 m (1,594 ft) AHD |
| Height (thalweg) | 180 m (591 ft) |
| Length | 92 m (302 ft) |
| Width (crest) | 670 m (2,198 ft) |
| Width (base) | 700 m (2,297 ft) |
| Dam volume | 14.1×106 m3 (498×106 cu ft) |
| Spillway type | Uncontrolled chute |
| Spillway capacity | 2,750 m3/s (97,115 cu ft/s) |
| Reservoir | |
| Creates | Dartmouth Reservoir |
| Total capacity | 3,856 GL (848×109 imp gal; 1,019×109 US gal) |
| Inactive capacity | 71 GL (16×109 imp gal; 19×109 US gal) |
| Catchment area | 3,600 km2 (1,390 sq mi) |
| Surface area | 6,300 ha (15,568 acres) |
| Power station | |
| Name | Dartmouth Power Station |
| Operator(s) | AGL Hydro |
| Commission date | January 1981 |
| Type | Francis-type |
| Turbines | 1 x 180 MW (241,384 hp) |
| Installed capacity | 150 MW (201,153 hp) |
| Annual generation | 310 GWh (1,116 TJ) |
| Website Dartmouth Dam at the Murray-Darling Basin Authority |
|
The Dartmouth Dam is a very large dam in the north-east of Victoria, Australia. It's built across several rivers, including the Mitta Mitta, Gibbo, and Dart rivers. This dam is important for many reasons. It helps with irrigation (watering farms), makes hydro-electric power, and stores water for people to use.
The huge lake behind the dam is called Dartmouth Reservoir, sometimes known as Lake Dartmouth. Near the dam wall is the Dartmouth Power Station. This station uses the dam's water to create electricity for the national power grid.
About 9 kilometers (5.6 miles) downstream from the main dam, there's a smaller pond called the Dartmouth Dam Regulating Pond or Banimboola Pondage. This pond is part of the dam's system and works with the nearby Banimboola Hydroelectric Power Station.
Contents
Building the Dartmouth Dam
Building the Dartmouth Dam started in 1973 and finished in 1979. It cost about $179 million Australian dollars. The dam wall is made of earth and rock. It rises 180 meters (about 590 feet) from its base, making it the tallest dam wall in Australia!
The dam wall is built with different layers. It has an inner core of earth, surrounded by special filter material made from crushed rock, and then a large amount of rock fill on the outside.
Dartmouth Reservoir: A Giant Lake
The Dartmouth Reservoir can hold a massive amount of water: 3,856 gigalitres (about 1,019 billion US gallons). To give you an idea, that's about 6.7 times the size of Sydney Harbour!
The dam is designed to release water slowly. It can let out about 12,000 megalitres (3.2 million US gallons) of water per day during normal operations.
The top of the dam's spillway is 486 meters (1,594 feet) above sea level and is about 92 meters (302 feet) long. A spillway is like a giant overflow channel. If the reservoir gets too full, water flows over this spillway and down a long concrete chute. This water then returns to the river below.
When the reservoir is almost full (at 99% capacity), the dam operators carefully release water downstream. They try to send water through the power station first. Water only flows over the spillway if there's a lot of rain and the reservoir is very full. This helps prevent floods downstream and also allows the power station to keep making electricity.
The Dartmouth Dam stores water from the snowy mountains of Victoria. This water is released in summer to help irrigate farms along the Mitta Mitta River and the larger Murray River. The reservoir's water levels don't change as much as some other dams because its inflow and outflow capacity is quite small compared to its huge size.
The reservoir is also a popular spot for fishing, especially for trout. Fish are regularly added to the lake to keep it stocked.
Making Electricity: Dartmouth Power Station
The Dartmouth Power Station started operating in January 1981. It has one large Francis turbine that generates electricity. This turbine is the biggest single hydroelectric turbine in Australia, with a capacity of 180 megawatts. The power station is owned and run by AGL Hydro.
In May 1990, there was a serious accident at the power station. A foreign object got into the turbine, causing it to stop suddenly. This damaged the power station and the dam's control systems. For a while, it was difficult to release water from the dam in the usual way. Engineers had to create a temporary system using large pipes to siphon water over the spillway. The power station was rebuilt and started working again in 1993.
In 2003, the smaller regulating pondage downstream was made bigger. This helped the power station generate electricity more efficiently. The power station is connected to the main electricity grid by a power line that goes to Mt Beauty, about 40 kilometers (25 miles) away.
Impact on Rivers and Fish
Building and operating the Dartmouth Dam has changed the way the Mitta Mitta and Murray rivers flow. One big change is that the water released from the dam is much colder than it would naturally be. It can be up to 10°C (18°F) colder!
This "cold water pollution" has had a big effect on fish. It led to the disappearance of fish like the Murray cod, Trout cod, and Macquarie perch from the Mitta Mitta River soon after the dam was built. It also contributed to the disappearance of the Eel-tailed catfish from the upper parts of the Murray River.
Images for kids
-
Upper intake tower exposed.
-
Power station, wall and spillway.
-
First sight of the reservoir.
-
The shore opposite entrance point.
