Happy Valley Reservoir (Adelaide, SA)

 valley, lake, water, reservoir, invisible

Happy Valley Reservoir was built between 1892 and 1897 at a cost of $1.8 million.

The project involved three major works:

Creating an off-stream storage with a diversion channel to prevent polluted water from entering the dam
Construction of a diversion weir to transfer water from the Onkaparinga River to the reservoir via a 5 kilometre long, 3 metre diameter tunnel
A stone outlet tower and a 2.4 kilometre, 2 metre diameter tunnel under Black Road to supply piped water to Adelaide
The 547,000 cubic metres of fill that was needed was hauled to the site by small steam locomotives. This was the first time mechanical equipment of this type was used specifically for dam construction in South Australia.



In 2002, a $22 million rehabilitation project was launched at Happy Valley as part of a program designed to meet or exceed national and international guidelines for best practice management of dam structures. The work was completed in August 2004 and involved strengthening and raising the wall with 300,000 cubic metres of fill, upgrading the spillway and modifying the pipes and roadway below the dam to allow construction of the new wall.



Capacity: 11,600 megalitres

Top water level: 145.3 metres above sea level

Length of wall: 806 metres

Height of wall: 23.6 metres

Type of wall: Earth with clay core

Area of water spread: 178 hectares


www.postcards.sa.com.au/features/happy_valley.html