Clarendon Weir
Coordinates35.11165°S 138.634812°E
CountryAustralia
Location, Adelaide, South Australia
PurposeW
StatusO
Construction began1894
Opening1896
BuilderJ Wishart & Son
OwnerGovernment of South Australia
OperatorSA Water
Dam crossesOnkaparinga River
Dam height15 m (49 ft)
Dam length83 m (272 ft)
Dam width crest61 m (200 ft)
Dam volume47 e3m3
Spillway capacity1,030 m3/s (36,000 cu ft/s)
Res capacity total320 ML
Res catchment445 km2 (172 sq mi)
Res surface8.5 ha (21 acres)
Res elevation171 m (561 ft)
Clarendon Weir
Designation 1SAHR
Designation1 offnameClarendon Weir, Onkaparinga River
Utilities - Weir8 November 1984
Designation1 number12711

The Clarendon Weir is a concrete gravity weir across the Onkaparinga River, located in the suburb of , approximately 20 kilometres (12 mi) south of the Adelaide city centre, in South Australia.[1]

Overview

Built in 1894–96 as a solution to Adelaide's sewer problems, the weir supplied water to the Adelaide plains to flush the sewers as there simply was not enough water to keep the population healthy. A tunnel was built with ponies and carts through the hills to Happy Valley where a reservoir was built. The water flowed by gravity from the Weir through the tunnel to Happy Valley Reservoir. There is no other catchment for this reservoir. Mt Bold Reservoir was added in the 1940s to again supplement Adelaide's water supply with the Clarendon Weir acting as a holding dam down stream. The water is used to supply about half of the Adelaide region's water needs.[citation needed]

The weir wall is 15 metres (49 ft) high and 83 metres (272 ft) long. When full, the reservoir has capacity of 320 megalitres and covers 8.5 hectares (21 acres), drawn from a catchment area of 445 square kilometres (172 sq mi). The uncontrolled spillway has a flow capacity of 1,030 cubic metres per second (36,000 cu ft/s).[2]

In the mid-1960s, the wall of the Clarendon Weir, originally constructed with large blocks of Macclesfield marble, was raised from 14 metres (46 ft) to its current height of 14.6 metres (48 ft).[3]

The weir was listed on the former Register of the National Estate, and was added to the South Australian Heritage Register on 8 November 1984.[4][5]

See also

References

  1. ^ "Search results for 'Clarendon Weir' with the following datasets selected - 'Suburbs and Localities' and 'Gazetteer'". Location SA Map Viewer. South Australian Government. Retrieved 26 April 2018.
  2. ^ "Register of Large Dams Australia-2015" (Excel. Requires download. Row 108). ANCOLD. January 2022. Retrieved 2026-03-05.
  3. ^ "Clarendon Weir - Onkaparinga River". Built Heritage Property Details. City of Onkaparinga. Retrieved 26 April 2018.
  4. ^ Retrieved 26 April 2018.
  5. ^ "Clarendon Weir, Onkaparinga River". South Australian Heritage Places Database. South Australian Government. 8 November 1984. Retrieved 26 April 2018.