A coastal reservoir for Greater Sydney water supply in Shoalhaven river – a preliminary study

Abstract

Australia is the driest inhabited continent on earth, and most of its population is concentrated along the coastal line. In recent years, extreme climate events such as floods and droughts have occurred more frequently. Sydney, as the largest city in Australia, requires a reliable water supply. Many solutions have been conducted to secure its water supply. This paper is focused on future water supply for the Greater Sydney area. The analysis supports the concept that in runoff-rich regions like Greater Sydney, there is no water shortage but a lack of water storage. The novel technology, coastal reservoirs, can increase the storage capacity of freshwater in the sea. The average annual discharge at Shoalhaven River mouth is estimated as 1,334 gigalitres. By comparison, the average annual inflow to the Warragamba Dam, which supplies 80% of Sydney’s drinking water, is 1,069 gigalitres. This paper discusses how to apply a Coastal Reservoir at the Shoalhaven River mouth to secure additional water supply for ever-growing Greater Sydney. The proposed reservoir with a capacity of 500 gigalitres could supply 1,000 gigalitres of water per year with a reliability of 90%. A preliminary design of the reservoir is demonstrated.