Stress increases on Gnangara groundwater levels
Released 06 Feb 2008
Careful monitoring of the Gnangara Mound's groundwater over the past 11 years has revealed that currently it is the lowest on record.
Department of Water director of water resource use Rob Hammond has linked the levels to the decline in rainfall over the same period and urged the public to support the department's moves to protect the state's water resources.
Mr Hammond said groundwater levels in the Gnangara Mound were a sensitive environmental barometer. Data compiled from extensive groundwater monitoring showed the biggest factor affecting groundwater levels was rainfall.
"Some of that drop in levels is due to people sucking water out of the mound, but most of the drop is due to the fact that we are getting less rain.
"We want to avoid our groundwater levels dropping too far, not only for the environment but also to maintain a healthy system that will be able to help meet future water needs.
Mr Hammond said the Department of Water had established programs such as the Gnangara Mound metering project and had set up garden bore rostering regimes to help address the issue.
"Putting meters on bores allows us to better calculate how much water is being used and to adjust our water allocation regimes accordingly," he said. "It also allows the bore users such as horticultural licensees to manage production within their water allocation.
"Other options to help support the aquifer recharge process are also available if the Gnangara Mound becomes too stressed.
"For example, the water efficiency measures we promote and encourage water users to put in place – recycling water, watering rosters and generally being careful with water."
Mr Hammond said the Gnangara Mound groundwater system provided up 60 per cent of the Perth metropolitan area's drinking water as well as supporting agriculture, parks and recreation, industry and homes.
"Managing abstraction from the system is a high priority for the Department of Water and a draft management plan is expected to be available for public comment by the end of this month.
Contact: Peter Collins
Phone: (08) 6364 6848 / 0434 603 441