Background
This RAAFA retirement village of about 200 two to three bedroom units is located just south of Mandurah on what is sometimes called the island bounded by the ocean, the estuary and two bridges. Each of the three aquifers under this land is either over-allocated or saline, or both.
Action
The Civil Group derived an innovative and self-contained and always self- sustaining method to capture, store and then re-use water for irrigation purposes.
Every paved or roof area in the Village is drained into soakwells that let the water soak down onto the shallow aquifer two to three metres under the site. Even though this aquifer is saline, the fresh runoff water floats on top of the more saline layers, so the aquifer storage and recovery system has a clever set of shallow bores from which the fresh water is skimmed into pumps and then stored in a tank for use as irrigation water.
Outcomes
RAAFA was able to obtain a groundwater water extraction licence four times greater than the usually permitted allocation in this district. The water is completely sustainable. Many hundreds of thousands of dollars were saved with this system from reduced headworks and an ongoing and significant reduction in the use of scheme water.