Bill Gunn Dam

Bill Gunn Dam
View from Cunninghams Crest Lookout
Bill Gunn Dam is located in Queensland
Bill Gunn Dam
Location of the Bill Gunn Dam
in Queensland
CountryAustralia
LocationSouth East Queensland
Coordinates27°37′40″S 152°22′37″E / 27.62778°S 152.37694°E / -27.62778; 152.37694
PurposeIrrigation
StatusOperational
Opening date1987
Operator(s)SEQ Water
Dam and spillways
Type of damEmbankment dam
ImpoundsOff-stream
Height18 m (59 ft)
Length1,160 m (3,810 ft)
Dam volume722×10^3 m3 (25.5×10^6 cu ft)
Spillway typeUncontrolled
Spillway capacity5 m3/s (180 cu ft/s)
Reservoir
CreatesLake Dyer
Total capacity6,940 ML (1,530×10^6 imp gal; 1,830×10^6 US gal)[1]
Catchment area3 km2 (1.2 sq mi)
Surface area100 ha (250 acres)
Maximum length1,100 m (3,600 ft)
Maximum width600 m (2,000 ft)
Maximum water depth10.7 m (35 ft)
Normal elevation110 m (360 ft) AHD
Website
www.seqwater.com.au

The Bill Gunn Dam is an earth-fill embankment dam with an un-gated spillway located off-stream in Laidley Heights in the South East region of Queensland, Australia. The main purpose of the dam is for irrigation of the Lockyer Valley.[2][3] The resultant reservoir is called Lake Dyer.

Location and features

Located 1.5 kilometres (0.93 mi) west of the town of Laidley, the dam was developed to increase the capacity of the existing Lake Dyer, a natural lake adjacent to Laidley Creek, a tributary of Lockyer Creek. The dam was named after the Queensland politician Bill Gunn and is managed by SEQ Water.[2]

The 1,170 m (3,840 ft) long earthfill structure has a maximum height of 12 m (39 ft) and an overflow spillway which diverts excess water into Laidley Creek. The dam has a storage capacity of 6,950 megalitres (1,530×10^6 imp gal; 1,840×10^6 US gal) and a maximum surface area of 108 hectares (270 acres).

Water from the dam is used for irrigation, in the densely cropped Lockyer Valley.[2] Bill Gunn Dam suffers from high drawdowns and summer evaporation which together with phosphate fertilizer creates significant blue green algae problems.[2] In November 2005, during drought conditions in the area, the dam's water level declined to just 1%.[4]

Recreation

A boating permit is not required, however a maximum of eight boats are allowed on the lake at once.[2] A single concrete boat ramp and some facilities for visitors, including campers, are available at a lakeside caravan park which is managed by the local council.

The dam is stocked with silver perch and golden perch, while bony bream, spangled perch and eel-tailed catfish breed naturally.[2] A Stocked Impoundment Permit is required to fish in the dam.[5] The poor water quality means that fish caught in the dam may, at times of an algae outbreak, be a health hazard if eaten.[2]

See also

References

  1. ^ "Bill Gunn Dam". Water supply: Dams and weirs. Seqwater. 2014. Archived from the original on 26 August 2014. Retrieved 26 June 2014.
  2. ^ a b c d e f g Harrison, Rod; James, Ernie; Sully, Chris; Classon, Bill; Eckermann, Joy (2008). Queensland Dams. Bayswater, Victoria: Australian Fishing Network. p. 94. ISBN 978-1-86513-134-4.
  3. ^ "Register of Large Dams in Australia" (Excel (requires download)). Dams information. Australian National Committee on Large Dams. 2010. Archived from the original on 12 December 2013. Retrieved 23 June 2014.
  4. ^ Rebecca Dull (29 November 2005). "Falls make small impact on dam levels". Ipswich Queensland Times. APN News & Media. Archived from the original on 10 August 2011. Retrieved 28 April 2008.
  5. ^ Fishing in Queensland dams? You may need a permit. Archived 29 August 2007 at the Wayback Machine