Somerset Dam

Somerset Dam
Wall of Somerset Dam
Location of the Somerset Dam in Queensland
Country	Australia
Location	South East Queensland
Coordinates	27°06′55″S 152°33′24″E / 27.1154°S 152.5566°E / -27.1154; 152.5566
Purpose	Potable water supply Flood mitigation Recreation Hydroelectricity[1]
Status	Operational
Construction began	1935 (1935)
Opening date	1959 (1959)
Operator(s)	SEQ Water
Dam and spillways
Type of dam	Gravity dam
Impounds	Stanley River
Height	50 m (160 ft)[1]
Length	305 m (1,001 ft)[1]
Width (base)	41 m (135 ft)[2]
Dam volume	203×10^3 m3 (7.2×10^6 cu ft)[1]
Spillway type	Gated
Spillway capacity	4,650 m3/s (164,000 cu ft/s)[1]
Reservoir
Creates	Lake Somerset
Total capacity	904,000 ML (199×10^9 imp gal; 239×10^9 US gal)[2]
Active capacity	380,000 ML (84×10^9 imp gal; 100×10^9 US gal)[1][3]
Inactive capacity	524,000 ML (115×10^9 imp gal; 138×10^9 US gal)[2]
Catchment area	1,330 km2 (510 sq mi)[1]
Surface area	4,350 ha (10,700 acres)[1]
Maximum length	52 m (171 ft)
Maximum width	7 m (23 ft)
Normal elevation	108 m (354 ft) AHD
Somerset Dam
Commission date	1959 (1959)
Installed capacity	3.2 MW (4,300 hp)
Annual generation	12 GWh (43 TJ)
Website www.seqwater.com.au

The Somerset Dam is a mass concrete gravity dam with a gated spillway across the Stanley River in Queensland, Australia. It is within the locality of Somerset Dam in the Somerset Region in South East Queensland. The main purpose of the dam is the supply of potable water for the Brisbane, Gold Coast and Logan City regions. Additionally, the dam provides for flood mitigation, recreation and for the generation of hydroelectricity.^[1] The impounded reservoir is called Lake Somerset.

As early as the 1960s it had become clear that the dam could not meet the water requirements of the region by the 1980s.^[4]

The dam, lake and surrounding village of Somerset are named in honour of Henry Plantagenet Somerset, a local grazier and Member of the Legislative Assembly of Queensland who represented the seat of Stanley^[2] from 1904 until 1920.