It is estimated that total annual consumption of water in South Australia exceeds 1 million megalitres of which 651 is derived from surface sources and 35% from groundwater. Most water is used for irrigation (631) but reticulited water supplies including water for industry accounts for about 27%. The remaining 10% is used by stock, of which approximately 7.5% is lost from flowing wells in the Great Artesian Basin. Groundwater forms about 35% of irrigation supplies, mainly from aquifers of the Murray and Otway Basins, but there is significant use for this purpose in the St. Vincent Basin and Mt. Lofty Ranges. Although it forms only about 8% of the quantity used for public water supplies, groundwater is an important resource in the South East and on Eyre Peninsula. These two areas together account for approximately 90% of groundwater used for town water supplies, exceeding 19 000 Ml in 1976/77.