How irrigation water is supplied
The irrigation season runs from October to April – the precise dates depending on the weather. Water is released to Harvey Water from seven Darling Scarp dams controlled and maintained by the Water Corporation. A water storage fee is paid to the Water Corporation on the basis of the amount of water released (measured at five delivery points). Harvey Water has rights to its own water under its 3 licences and does not buy water from the Water Corporation.
Harvey Water is responsible for the delivery infrastructure - a network of channels and pipes: 83 km lined channels, 172 km unlined channels and 430 km of pipeline with a total of 1 536 supply points. The Harvey district is partly piped and Waroona was converted to a piped system in 2003 that will allow 24 hour/day access to water under gravity pressure suitable for operating sprinklers. The aim is to convert most of the system to pipes.
The Harvey Water Irrigation Area is relatively unique among Australian schemes because it is entirely gravity fed. This is possible because:
- the water is sourced from a large number of dams relative to the area served
- the land area served is narrow compared to its length; and
- there are relatively steep grades across the width.
Because the scheme cannot supply all properties at once, a daily allocation system is used to meet individual farmer’s needs while maximising the efficiency of the distribution system and minimising water wastage.
Customers order water and water controllers schedule water supply to farms on the same delivery route. The 9-10 water controllers are based within the area and are responsible for their own clients. They operate the automated distribution system via computer using SCADA software to deliver the water as scheduled.
