geo.wikisort.org - Reservoir

The Leslie Harrison Dam is an earth-fill embankment dam across the Tingalpa Creek that is located in the South East region of Queensland, Australia. The main purpose of the dam is for potable water supply of the Redland City in Brisbane.[1][4] The impounded reservoir is called Tingalpa Reservoir. The dam was named after Robert Leslie Harrison, a Queensland parliamentarian who died in April 1966.^{[citation needed]}

Leslie Harrison Dam
The Leslie Harrison Dam, in 2014
Location of the Leslie Harrison Dam in Queensland
Country	Australia
Location	South East Queensland
Coordinates	27°31′41″S 153°10′49″E
Purpose	Potable water supply
Status	Operational
Opening date	1968 (1968) 2004 (2004) (wall raised/gates installed)
Operator(s)	SEQ Water
Dam and spillways
Type of dam	Embankment dam
Impounds	Tingalpa Creek
Height	25 m (82 ft)[1]
Length	525 m (1,722 ft)[1][2]
Dam volume	315×10^3 m3 (11.1×10^6 cu ft)[1]
Spillway type	Vertical lift gates[3]
Spillway capacity	1,450 m3/s (51,000 cu ft/s)[1]
Reservoir
Creates	Tingalpa Reservoir
Total capacity	13,206 ML (2.905×109 imp gal; 3.489×109 US gal)[2][4]
Catchment area	87 km2 (34 sq mi)[1][2]
Surface area	470 ha (1,200 acres)[2][4]
Website www.seqwater.com.au

Location and features

The dam is located between the suburbs of Capalaba, Chandler and Burbank, approximately 16 kilometres (9.9 mi) southeast of Brisbane. The primary inflow of the reservoir is the Tingalpa Creek, not far above its mouth at Waterloo Bay.[4] The dam is one of a number of dams connected to the South East Queensland Water Grid, and the dam provides approximately 20% of the water supply for Redland City.

External video
Spillway gates removed, 2015

Completed in 1968, the earthfill dam structure is 25 metres (82 ft) high and 535 metres (1,755 ft) long. The 315-thousand-cubic-metre (11.1×10^⁶ cu ft) dam wall holds back the 13,206-megalitre (2.905×10⁹ imp gal; 3.489×10⁹ US gal) reservoir when at full capacity. From a catchment area of 87 square kilometres (34 sq mi) that includes much of the northern slopes of the Venman Bushland National Park, the dam creates Tingalpa Reservoir, with a surface area of 470 hectares (1,200 acres). Controlled gates were added to the spillway in 1984 to increase water supply to the region, and removed in 2014 to improve dam safety.[5] The spillway has a discharge capacity of 1,450 cubic metres per second (51,000 cu ft/s).[1] Initially managed by the Redland City Council, management of the dam was transferred to Seqwater in July 2008 as part of a water security project in the South East Queensland region, known as the South East Queensland Water Grid.[6] In 1984, the dam wall was raised and gates were installed,[3] and in 2014, work began on improving the safety of the dam after Seqwater completed a major investigation of its operating dams,[7] which includes draining the dam to approximately 50% capacity.[8]

Dam improvement program

In 2012–13, an independent review of Seqwater's 26 referable dams found improvements were needed at a number of dams, including Leslie Harrison, to meet the revised Queensland Dam Safety Guidelines.

The detailed design for the upgrade of Leslie Harrison Dam has been completed. Construction is expected to begin in mid-2018 and will take around 12 months to complete, subject to weather. Features of the upgrade design include:

• widening and strengthening of the dam wall
• anchoring the spillway
• improving resilience to extreme weather events and earthquakes
• the gates will not be returned to the spillway.[5]

Recreation

There are no plans to introduce recreation at Leslie Harrison Dam. In 2014, Seqwater engaged experts to conduct a water quality study and develop a screening tool to improve understanding of the impact recreation has on water quality in drinking water lakes. The landmark study was one of the most complex and comprehensive of its kind ever undertaken in Australia. In 2016, a water quality assessment was conducted at Leslie Harrison Dam using this screening tool. The assessment found, given the dam's role as a drinking water source for the Redlands, recreation cannot be considered because of unacceptable risks to water quality.[9]

See also

• List of dams in Queensland

References

External links

• "Flood Procedure Manual" (PDF). SEQ Water (PDF). Flood Commission. January 2010.
• "Leslie Harrison Dam". Dam Improvement Program. SEQ Water. June 2014.

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