Enoggera Dam

Enoggera Dam

Enoggera Dam (photo taken at
Brisbane Forest Park on 23 April 2007)
Location of Enoggera Dam in Queensland
Country Australia
Location 10 km (6.2 mi) West of Brisbane, Queensland
Coordinates
Status Operational
Construction began 1864
Opening date 1866
Construction cost ₤71,000
Dam and spillways
Type of dam clay cored earthfill dam
Impounds Enoggera Creek
Reservoir
Creates Enoggera Reservoir
Capacity 4,500,000 m3 (3,600 acre·ft)
Catchment area 33 km2 (13 sq mi)
Surface area 358.15 ha (3.58 km2)
Reservoir length 2,376 m (7,795 ft)
Max. reservoir width 640 m (2,100 ft)

The Enoggera Dam, which is located within the inner, western suburb of Enoggera Reservoir, in Brisbane, Queensland, and was constructed in 1866. It was built on Enoggera Creek and was the first major dam built in Queensland (it was the second major dam built in Australia — the first major dam having been built in Victoria). It is rare as one of the few remaining examples in Queensland of an intact and functioning reservoir and treatment plant from this period in time. The clay cored earthfill dam was designed and built by Joseph Brady.[1]

It was managed by the Brisbane City Council until July 2008, but is now managed by Seqwater.

Contents

Water supply

Water supply problems plagued Brisbane's early years. Soon after the Brisbane Municipal Council was established in 1860, a Water Supply Committee was formed.[2] The earliest reservoir in Brisbane, which was located at the intersection of the present George Street and Roma Street, suffered from accumulation of dead animals and vegetable manner.[2]

Dry periods pronounced water quality problems in both Enoggera Dam and Gold Creek Dam built after the Enoggera reservoir was completed. The Mount Crosby Weir and pumping station alleviated some concerns but flooding of the Brisbane River was problematic. It was not until 1912 that water from Enoggera Dam was filtered.[3]

It was decommissioned in 2003, then in early 2006 water from Enoggera Dam was again added to inner north-west Brisbane's drinking water supply, when drought had reduced South East Queensland's water supply to critical levels.

Site selection

Breakfast Creek was rejected by the Water Supply Committee because it was too close to the town.[2] Thomas Oldham, an engineer who had worked on water supply to Melbourne, was employed to conduct a survey and solve Brisbane's problems.

One of Oldham's site recommendations on the Brisbane River near Dutton Park was dismissed before of its prohibitive costs.[2] The other site Oldham suggested was selected because it was where Enoggera Creek left the range.[4] The Surveyor-General, Augustus Gregory also suggested a site on Ithaca Creek. This location was abandoned because it had a small catchment size.

Enoggera Creek had a large catchment that rose higher in the D'Aguilar Range and had more smaller creeks flowing into it.[4] The location was steep and heavily timbered. It took eighteen months and ten different contractors to just clear the site.[4]

Construction

The Queensland Government didn't have confidence in the Council to supervise the dam's construction. After requesting revised plans and detailed cost estimates the Board of Waterworks was established to oversee the project.[2]

Approval for the dam's construction was given in May 1864. Work began in August 1864 with water flowing by July 1866.[5] A single cast-iron mains pipe, 8 inches (20 cm) in diameter, supplied the town of Brisbane. By 1869 the pipelines were extended to a total of eighteen kilometers, benefiting between five to six thousand people.[4]

The original cost was ₤50,000, which was raised to ₤65,000.[5] By the end of 1870 more than ₤71,000 had been spent and water supply for the rapidly growing city of Brisbane was not being met by strong demand. To solve the problem another dam, Gold Creek Dam was approved in 1881.

A spillway was added in 1976.[1] Seven metres was added to the height of the dam wall for flood mitigation in the same year.[4]

Access for recreation

There are walking tracks in the area, and no permit is required. However, no on water activities are permitted. This is being reviewed by SEQ Water, due late 2010.

See also

References

  1. ^ a b "Enoggera Reservoir (entry CHIMS19580 )". Queensland Heritage Register. Queensland Environmental Protection Agency. http://www.epa.qld.gov.au/chims/placeDetail.html?siteId=19580. Retrieved 2009-05-28. 
  2. ^ a b c d e Brisbane 150 Stories. Brisbane City Council Publication. 2009. pp. 12–13. ISBN 978-1-875091-60-6. 
  3. ^ Oliver, Bill (2008). Carolyn Fitz-Gerald. ed. "Floods, water quality and river crossings, Mount Crosby 1890-1931". Brisbane:Water, Power and Industry Paper No. 20 (Kelvin Grove, Queensland: Brisbane History Group): 33. ISBN 9780975179338. 
  4. ^ a b c d e Horton, Helen (1988). Brisbane's Back Door: The story of the D'Aguilar Range. Bowen Hills, Queensland: Boolarong Publications. pp. 74–77. ISBN 086439036 X. 
  5. ^ a b Laverty, John (2008). Carolyn Fitz-Gerald. ed. "The politics of Brisbane's early water supply schemes". Brisbane:Water, Power and Industry Paper No. 20 (Kelvin Grove, Queensland: Brisbane History Group): 23–25. ISBN 9780975179338.