Piping the Collie River Irrigation District

Harvey Water, as a supplier of irrigation water to the Collie River Irrigation District (CRID), has over recent months been working alongside Collie Water and CRID farmers developing the design parameters to replace the current open channel irrigation scheme with a closed pipe system.

The CRID is the southernmost of three irrigation districts managed by Harvey Water, with Harvey and Waroona districts to the north. The CRID is the last remaining area to be piped. The aim is to convert clay and concrete lined channels in the CRID to a buried network of high density polyethylene (HDPE) pipes.

The CRID comprises over 200km of open channels which commenced construction during the Great Depression. Due to the age of these channels, their condition is deteriorating. With the growing imperative to maximise water use efficiency combined with climate impacts, piping is the best solution to system losses through leakage, seepage and evaporation. Water is supplied to over 220 farmers who irrigated just less than 3,000 hectares of land during the irrigation season, which generally runs from September until May.

For this group of irrigators, the bulk of their water comes from Wellington Dam, which is to the east in the Wellington National Park. The water is released from Wellington Dam, from where it flows to Burekup Weir which serves as a gravity ‘header tank’ for the channel system. Irrigators can ‘order’ their water from the system based on their seasonal allowance. Harvey

Water’s Water Controllers manage these requests, releasing water from the Dam and Weir at the appropriate time according to demand. The journey from Wellington Dam to any given irrigator, through the open channels, results in losses in excess of 30% annually.

Orbit B-hyve Controllers 2020_HR Products Outlines.ai 1 25/02/2020 8:01:31 AMrbit B-hyve Controllers 2020_HR Products Outlines.ai 1 25/02/2020 8:01:31 AM The proposed new piping project will include new supply points, a modern automated delivery system, and most importantly reduce water loss to below five percent annually. Each farmer that will be impacted by the project has been contacted by Harvey Water, and given the opportunity to have their input into the capacity of potential future piped supply point(s). Beyond the farm gate, irrigation infrastructure will be the responsibility of individual landowners. The project poses numerous advantages to CRID farmers by way of a more reliable and efficient delivery of water to irrigators. Project viability is however contingent upon the Myalup Wellington Project commencing. Once the irrigator consultation stage has concluded, Harvey Water, in consultation with project proponent Collie Water, will extend invitations to qualified consultants to provide a detailed design. Progressing beyond design will be linked to the commencement of the broader Myalup Wellington Project.