| Lockyer Creek | |
|---|---|
Lower Lockyer Creek, 2011 |
|
| Mouth | confluence with the Brisbane River |
| Basin countries | Australia |
| Length | 100 km |
| Basin area | 3,032 km2 (1,171 sq mi) |
| Left tributaries | Buaraba Creek, Redbank Creek, Sheep Creek, Alice Creek, Murphy's Creek |
| Right tributaries | Plain Creek, Laidley Creek, Sandy Creek, Tenthill Creek, Ma Ma Creek, Flagstone Creek, Gatton Creek |
Lockyer Creek is a major drainage system in the Lockyer Valley of South East Queensland that flows into the Brisbane River a few kilometres north-north/east of Lowood, and downstream from the Wivenhoe Dam. The creek is named after Edmund Lockyer and is close to 100 kilometres (62 mi) in length.[1]
Contents |
Draining parts of the western Scenic Rim, the creek's headwaters are in the Main Range, a small sub-section of the Great Dividing Range. Its tributaries drain the slopes east of Toowoomba and areas to the north of Gatton. The total stream length of the Lockyer Creek network is 6,056 km (2,338 sq mi).[2]
The total catchment area is 3,032 km2 (1,171 sq mi),[3] and covers nearly one quarter of the total catchment area of the Brisbane River.[1] O'Reillys Weir is located about one kilometre upstream from the creek's confluence with the Brisbane River.
Five kilometres (≈3 miles) upstream from the junction of Lockyer Creek and the Brisbane River, is the Wivenhoe Dam. Tributaries flowing into Lockyer Creek include Flagstone Creek, Sandy Creek, Alice Creek, Laidley Creek, Tenthill Creek, Murphys Creek and Ma Ma Creek.[3]
Lower areas of the catchment have been cleared for intensive agriculture.[2] Upper parts of the catchment remain mostly forested,[2] partially protected within Lockyer National Park formerly known as White Mountain State Forest. Bushfires, soil protection, water quality and flood management are the main resource management issues for the waterway.[4] The creek is significantly degraded. The poor conditions have resulted in unstable stream banks and gully erosion from the removal of riparian vegetation.[2]
There are a total of nine major private and public water storages within this drainage system, including Atkinson Dam, Bill Gunn Dam and Lake Clarendon.[3] The Lockyer Creek valley had been one of the driest catchments in Queensland during the recent droughts in Australia.
In late 2010 the 2010–2011 Queensland floods began and on 10–11 January 2011 the creek experienced severe flash flooding.[5] During the floods the creek reached 18 m (59 ft) deep,[6] a record that was higher than what was experienced during the 1974 Brisbane flood.[6]
The Bureau of Meteorology recorded a rise of 8 metres (26.2 ft) in 23 minutes during the flash flood but initially dismissed the reading as a fault.[7] It was estimated that 4,000 tonnes (4,000 megalitres; 1,057 Million US gallons) of water per second flowed through Lockyer Creek, leading to the use of descriptive phrases such as "wall of water", or even "inland tsunami".[7]
A report by GHD Group for the Brisbane City Council suggested that flood mitigating dams on Lockyer Creek and Bremer River could be a useful measure for flood proofing Brisbane.[8]
The Lockyer Creek Bridge at Bageli Park, designed by William Pagan, is one of the largest of its type in Queensland and one of Australia's first reinforced concrete arch rail bridges.[9] The bridge, built in 1910/1911, features three spans, each supported by two arches, and appeared on a stamp that was part of a series featuring landmark bridges.[10] A model of the bridge has been featured in the Australian Model Railway Magazine of April 2011.[11] The bridge is still used for very heavy Brisbane bound coal and grain traffic. Another single arch bridge on the same line, but over a side gully, with the same name, is closer to Gatton and was built in 1903.[12] Further downstream in the district of Clarendon, an earlier railway structure (1885) built of timber piles with a deck of iron trusses, is possibly as spectacular. This bridge is no longer used by rail traffic.[13]