Ross River Dam

Ross River Dam
Ross River Dam at night, with open floodgates, pictured in 2008.
Location of the dam wall in Queensland
Country	Australia
Location	southwest of Townsville, North Queensland
Coordinates	19°24′35″S 146°44′15″E / 19.40972°S 146.73750°E / -19.40972; 146.73750Coordinates: 19°24′35″S 146°44′15″E / 19.40972°S 146.73750°E / -19.40972; 146.73750
Purpose	Flood control, water supply
Status	Operational
Opening date	1971
Dam and spillways
Type of dam	Embankment dam
Impounds	Ross River
Height	34.4 metres (113 ft)
Length	8,670 m (28,440 ft)
Dam volume	5,085×10^3 m3 (179.6×10^6 cu ft)
Spillway type	Controlled
Spillway capacity	674 m3/s (23,800 cu ft/s)
Reservoir
Total capacity	803,565 ML (1.76760×1011 imp gal; 2.12279×1011 US gal)
Active capacity	233,187 ML (5.1294×1010 imp gal; 6.1601×1010 US gal)
Catchment area	750 km2 (290 sq mi)
Surface area	82,000×10^3 m2 (880×10^6 sq ft)

The Ross River Dam is a rock and eathfill-filled embankment dam across the Ross River, located in Townsville in northern Queensland, Australia. Built initially for flood control, the impoundment created by the dam serves as one of the major potable water supplies for the region.^[1]

Location and features

The dam was constructed by Leighton Holdings^[2] in 1971 for the purposes of flood mitigation and water storage. Following a 2007 upgrade of facilities, the dam has a capacity of 250,000 megalitres (8,800×10^⁶ cu ft) and an earth rock embankment 8.67 kilometres (5.39 mi) in length and 34.4 metres (113 ft) high. The reservoir has a catchment area of 750 square kilometres (290 sq mi) with an controlled gated spillway. The reservoir has a current capacity of 233,187 megalitres (5.1294×10¹⁰ imp gal; 6.1601×10¹⁰ US gal) of water;^[3] and can hold up to 803,565 megalitres (1.76760×10¹¹ imp gal; 2.12279×10¹¹ US gal) of water in flood mitigation.^[4][5] When the dam gates open, water spills over into the Ross River. Visitors may view the dam from a viewing platform at Ross Park. The Ross Dam Pump Station supplies up to 232 megalitres (8.2×10^⁶ cu ft) of water to the Douglas Water Treatment Plant, where the water undergoes aeration, sedimentation, rapid sand filtration and chlorination treatment before being pumped to the reservoir where the water is distributed to Townsville.

At the base of the dam and on the banks of the Ross River is Ross Park, part of Riverway, with facilities for picnics or barbecues, as well as public toilets at this location.

Upgrade of the dam wall

• 2001 - a panel is experts in dam safety and construction undertook an investigation of the dam. Over two years, the panel conducted studies of the dam's construction with the world standards.
• 2003 - The report confirmed that upgrades were required and by late 2003 because the dam moved 10 centimetres (3.9 in) a year. At that rate, the dam would have burst in a 10-year period, causing the whole suburb of Kelso to be inundated. The first stage of lowering the spillway by 3.5 metres (11 ft) was underway, the lowering of the existing spillway has been done so the installing of dam gates to control the flow downstream and water storage levels can begin.
• 2004 - A combined GHD-MWH team was appointed to design the remaining work and manage the project. The contracting strategy was the first application of the 'Early Tenderer Involvement' (ETI) procurement model, developed by consultants ITN.
• 2005 -John Holland Group and Macmahon are awarded the construction contract.
• 2006 - Construction commenced with Constructing sand filters and supporting earthfill, extra rockwork to the dam embankment and the contraction of the gates.
• 2007 - Project completed late 2007.^[6]

The spillway gates have increased the dam's capacity by around nine percent, which is about 21,000 megalitres (740×10^⁶ cu ft) or four months extra supply of water. Three spillway gates span the 40-metre (130 ft) wide spillway. The upgrade was going to take until mid-2008 to complete unless rainfall delays construction, however it was completed ahead of time in late 2007. The cost was around A$115 million.

The dam's storage was temporarily reduced with the lowering of the spillway to make way for the new floodgates that have now been fitted.

Backup water can be supplied by pumping water from the Burdekin Dam if needed.

See also

• List of dams and reservoirs in Queensland

References

External links

• NQ Water
• Queensland Government; Townsville City Council (October 2014). "Regional Water Supply Security Assessment: Townsville" (PDF). Department of Energy and Water Supply. Queensland Government.