4 Quaternary silica sand deposits were assessed by 47 auger holes. The deposits comprise backshore dunes marginal to the lake and are a potential source of replenishment sand for metropolitan beaches. Only 1 deposit is mined at present, Nalpa no. 1 for foundry sand, although Tolderol was mined for sewerage sludge drying bed sand. Minor beneficiation would be required to meet glass sand specifications, as these deposits contain only minor iron impurity. Indicated reserves at Nalpa nos 1 and 2 and Wellington Lodge total 420 000, 320 000 and 32 000 tonnes respectively, with 10 000 tonnes inferred at Tolderol.