Mount Crosby Weir

Mount Crosby Weir
250px View from the southern side of the weir, looking upstream, towards the reservoir.
Location of the Mount Crosby Weir in Queensland
Country	Australia
Location	South East Queensland
Coordinates
Purpose	Potable water supply
Status	Operational
Opening date	1892 (1892)
Operator(s)	SEQ Water
Dam and spillways
Type of dam	Weir
Impounds	Brisbane River
Height	4.57 m (15.0 ft)
Length	81.4 m (267 ft)
Reservoir
Total capacity	3,430 ML (750×10^6 imp gal; 910×10^6 US gal)
Max. width	30.5 m (100 ft)
Normal elevation	141.34 m (463.7 ft) AHD
Website www.seqwater.com.au

The Mount Crosby Weir is a weir on the Brisbane River at Mount Crosby in South East Queensland, Australia. The project was instigated by John Petrie at the end of the 19th century. The town of Brisbane was expanding and seeking more reliable sources of drinking water than Enoggera Dam and Gold Creek Dam could provide.

Location and features

The location was selected because it was just above the upstream tidal flow of seawater at Colleges Crossing. The concrete structure was completed in April 1892. The dam wall rises 4.57 metres (15.0 ft) and is 81.4 metres (267 ft) in length. The weir has a capacity of 3,430 megalitres (750×10^⁶ imp gal; 910×10^⁶ US gal), making it one of the largest weirs in the region. Above the weir is a one-lane road which is open to the public.

The nearby Mount Crosby Pumping Station is used to transport drinking water that is sourced from the weir as well as Lake Manchester Dam built shortly after the Mount Crosby Weir.

Without an ongoing eradication program water hyacinth weed can choke the waters behind the weir, all the way upstream to Fernvale. In 2009 the weir was flushed to remove algai and organic matter that had built up.

See also

• List of dams in Queensland
• South East Queensland Water Grid