Cooby Dam

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Cooby Dam
Boat ramp at Cooby Dam.jpg
Boat ramp, 2014
Cooby Dam is located in Queensland
Cooby Dam
Location of the Cooby Dam in Queensland
Country Australia
Location Darling Downs, Queensland
Coordinates 27°23′09″S 151°56′24″E / 27.38583°S 151.94000°E / -27.38583; 151.94000Coordinates: 27°23′09″S 151°56′24″E / 27.38583°S 151.94000°E / -27.38583; 151.94000[1]
Purpose
Status Operational
Construction began
  • 1938 (1938)
Opening date
  • 1942 (1942)
Operator(s) Toowoomba Region Council
Dam and spillways
Type of dam Embankment dam
Impounds Cooby Creek
Height 30 m (98 ft)[2]
Length 207 m (679 ft)[2]
Dam volume 71×10^3 m3 (2.5×10^6 cu ft)[2]
Spillway type Uncontrolled
Spillway capacity 680 m3/s (24,000 cu ft/s)[2]
Reservoir
Creates Cooby Creek Reservoir
Total capacity 23,092 ML (5.080×10^9 imp gal; 6.100×10^9 US gal)[2]
Active capacity 19,703 ML (4.334×10^9 imp gal; 5.205×10^9 US gal)[3]
Inactive capacity 1,462 ML (0.322×10^9 imp gal; 0.386×10^9 US gal)[3]
Catchment area 159–169 km2 (61–65 sq mi)[3][2]
Surface area 301 ha (740 acres)[2][4]
Max. water depth 12.5 m (41 ft)[3]
Normal elevation 482 m (1,581 ft) AHD[3]

The Cooby Dam is a rock–fill embankment dam with an un–gated spillway across the Cooby Creek, a tributary of Condamine River, at Groomsville in the Darling Downs region of Queensland, Australia. The main purpose of the dam is for potable water supply of the Toowoomba region.[2][4] The impounded reservoir is called the Cooby Creek Reservoir.[1]

Location and features[edit]

The dam is located approximately 17 kilometres (11 mi) north of Toowoomba.[5] The other two storages used for Toowoomba are Perseverance Dam and Cressbrook Dam.

Completed in 1942 the rock–fill dam structure is 30 metres (98 ft) high and 207 metres (679 ft) long. The 71-thousand-cubic-metre (2.5×10^6 cu ft) dam wall holds back the 23,092-megalitre (5.080×10^9 imp gal; 6.100×10^9 US gal) reservoir when at full capacity. From a catchment area of 169 square kilometres (65 sq mi), the dam creates an unnamed reservoir, with a surface area of 301 hectares (740 acres) at a maximum depth of 12.5 metres (41 ft) when at full capacity. The uncontrolled un-gated spillway has a discharge capacity of 680 cubic metres per second (24,000 cu ft/s).[2] The dam is managed by the Toowoomba Region Council.[4]

Cooby Dam's lowest usable storage volume was recorded at 8% in January 2010.[3]

In July 2006, public outcry and a referendum with winning "No" vote rejected plans to place recycled water into Cooby Dam.[citation needed] In 2007, the idea was again resurrected when plans for an advanced water treatment plant to be built near Cooby Dam by the Toowoomba City Council were suggested.[6] The trial would test the re-use of recycled water into Toowoomba's drinking water supply.

In 2008, an emergency bore was used to extract water from the Great Artesian Basin to supplement water supplies for the dam as drought conditions reduced supply to critical levels.[7]

Recreational activities[edit]

A stocked impoundment permit is required to fish in the dam.[8][9]

See also[edit]

References[edit]

  1. ^ a b "Cooby Creek Reservoir (QLD)". Gazetteer of Australia online. Geoscience Australia, Australian Government. 
  2. ^ a b c d e f g h i j "Register of Large Dams in Australia" (Excel (requires download)). Dams information. Australian National Committee on Large Dams. 2010. Retrieved 2 July 2014. 
  3. ^ a b c d e f "Cooby Dam". Water supply & dams. Toowoomba Region Council. 2014. Retrieved 8 July 2014. 
  4. ^ a b c Harrison, Rod; James, Ernie; Sully, Chris; Classon, Bill; Eckermann, Joy (2008). Queensland Dams. Bayswater, Victoria: Australian Fishing Network. ISBN 978-1-86513-134-4. 
  5. ^ "Toowoomba's Dams - Perseverance Dam". Toowoomba Regional Council. Retrieved 2 November 2009. 
  6. ^ Mitchell, Selina (31 August 2007). "Residents again face recycled water". The Australian. Retrieved 2 November 2009. 
  7. ^ "Great Artesian Basin used to top up Toowoomba water supply". ABC News (Australia). 26 November 2008. Retrieved 2 November 2009. 
  8. ^ "Do I need a permit to go fishing in a dam?". Department of Agriculture, Fisheries and Forestry. Queensland Government. 5 February 2013. Retrieved 4 July 2014. 
  9. ^ "Cooby Dam (Cooby Creek Reservoir) - Toowoomba. Qld". Sweetwater Fishing Australia. Garry Fitzgerald. 2006. Retrieved 8 July 2014.