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.