Arrowsmith Groundwater Area
The Arrowsmith Groundwater Area covers approximately 10,300 km2 and produces ~151 million m3 of available groundwater per year. The largest aquifers occur in the Yarragadee and Parmelia formations and recharge primarily from rainfall recharge. The Superficial formation is an important resource near the coast. Water quality is variable. The Allanooka borefield, 50km south of Geraldton, supplies the integrated water scheme for Geraldton and Dongara/Port Denison.
Gascoyne Groundwater Area
The Gascoyne Groundwater Area extends north to Kalbarri and bounds the Arrowsmith Groundwater Area east to pastoral country. The largest groundwater aquifer occurs in the Yarragadee Formation, which has an estimated yield of 22.5 million m³/year. Groundwater from fractured rock aquifers in the eastern, inland part of the region is predominantly saline, with poor yields.
Gingin Groundwater Area
The Gingin Groundwater Area covers over 6,000 km2 of land and yields ~207 million m3 of available groundwater per year. Usage in the area is high and resources are approximately 75% allocated. The largest aquifers occur in the Superficial, Leederville, Parmelia and Yarragadee formations. Water quality is generally good, except in the aquifers along the Darling Scarp and in the coastal area south of Lancelin. The Leederville and Parmelia formations are currently over allocated.
Gnangara Groundwater Area
The Gnangara Groundwater Area is bounded by the Moore River, Swan River and Gingin Brook. It covers 2,200 km2 and recharges from rainfall. The largest aquifers are the Superficial, Mirrabooka, Leederville and Yarragadee North. Groundwater levels are declining due to a decrease in rainfall in recent years, an increase in abstraction of groundwater and the Gnangara Pine plantation.
Jurien Groundwater Area
The Jurien Groundwater Area covers over 5,000 km2 of land and produces ~84 million m3 of available groundwater per year. Groundwater abstraction in the area is low and only 21% of groundwater resources are allocated. Large aquifers occur in the Parmelia and Leederville formations. The Superficial formation is an important resource near the coast. Water quality is variable.
New Norcia Water Reserve
New Norcia Water Reserve is located in the western margin of the Yilgarn Craton and supplies water to the town of New Norcia. The water reserve recharges directly from rainfall, with approximately 40% of annual rainfall infiltrating into the water reserve. The New Norcia Water Reserve occurs in a shallow paleochannel and is considered vulnerable to contamination.
