The EVERARD sheet covers the NE Officer Basin and the Musgrave Complex in an area with about 220 mm annual rainfall. The crystalline basement rocks yield small supplies (median yield about 0.2 L/s), chiefly from fracture zones. Saprolite yields very little water. The Adelaidean rocks have a median yield of about 0.4 L/s. Drilling depths of 100 to 150 metres may be required. Sandstone units of the Officer Basin generally have moderate yields. The widespread Mintabie beds are of generally low permeablility, hence drilling to over 200 metres is required over much of the basin area. With the exception of some shallow aquifers underlying elevated parts of the area, water of under 1500 mg/L is limited to a region south of the Everard Ranges. Nitrates over 45 mg/L and fluoride over 1.5 mg/L are common there. To date no waters tested from the area with less than 1500 mg/L TDS have both nitrate less than 45 mg/L and fluoride less than 1.5 mg/L.