Southern Highlands Irrigation Scheme - Under Construction
The Southern Highlands Irrigation Scheme (SHIS) is one of five schemes which comprises Tasmanian Irrigation’s (TI) second suite of schemes known as ‘Tranche Two’.
The SHIS is centered around the township of Bothwell in the State's southern highlands region. This is an important cropping and livestock finishing region and also one of the most drought prone areas of Tasmania. This historic lack of a reliable water supply has prevented the region from reaching its full potential and as an example there has been two declared domestic water supply emergencies in the past. To date the water for irrigation purposes has been severely limited and has impacted growth in the region.
The SHIS will deliver 7,215 ML of high reliability irrigation water from a holding dam approximately 17km north-west of Bothwell to scheme participants via a 58km underground pipeline distribution network. The scheme has strong community support as evidenced by the uptake of all available water within the scheme during the sales period, as a result the scheme is completely sold out. Funding for construction has been approved and the project commenced construction in March 2016. The scheme is expected to be commissioned in the second half of 2017.
Winter flows from the Shannon River will be pumped up to the 7,600ML (minimum) storage dam. The dam is zoned earth filled and the wall is 500m long and 26m high. Gradco have been awarded the construction contract and mobilised to site in March 2016. Dam construction is progressing well and is about 60% complete. The majority of the materials required for construction will be sourced on site and the expected completion date is June 2017.
Shannon River Pump Station (SRPS)
The pump station will be located to the south of Waddamana Road on the banks of the Shannon River. The 1MW pump station is being constructed by Andrew Walter Constructions (AWC). The access road was completed in May 2016. The construction of the building is complete with the pumps and electrical work scheduled to be installed by April 2017. Operational flexibility has been a key driver in the design of the SRPS.
Distribution Pipeline and Booster Pump Stations
The 58km-long scheme distribution pipeline will run from Waddamana Road, south to Bothwell and on to Hollow Tree. The HDPE pipe has been manufactured by Zezt located in Wynyard and is being installed by AWC. As at the end of December 2016 60% of the 58km pipeline has been completed. The pipe diameter ranges from DN180mm up to DN710mm. A pipeline spur will provide water to farms to the east of Bothwell situated along Highland Lakes Road. The planned Nant Lane line has been withdrawn from the programme. Two small booster pump stations have been completed. One located on the eastern edge of Bothwell and the other along Hollow Tree Road at Montacute.
With construction due to be completed in June 2017 the scheme will be in a position to supply irrigation water to irrigators for the 2017/18 irrigation season.