Tallowa Dam, completed in 1976, is a concrete gravity dam with central overflow spillway, located on the Shoalhaven River, downstream from the river's confluence with the Kangaroo River. The dam wall of 325 m3 is 43 m high and 528 m in length. At 100% capacity, the dam wall holds back approximately 85500 ML and creates the impounded reservoir of Lake Yarrunga that has a surface area of 831 ha, drawn from a catchment area of 5750 km2. The spillway has a discharge capacity of 27600 m3/s. The 'full operating storage' for Tallowa Dam refers only to the amount of water in the dam that is available to be transferred to Sydney and the Illawarra. When full, the dam can hold approximately 90000 ML. 21800 ML is available to be transferred to the Sydney water supply. Other water from Tallowa Dam is provided to Shoalhaven City Council for supply to local communities. Water is also released from the dam as environmental flows for the Shoalhaven River. The construction of a large barrier across the river has meant that the means of travel for fish has been completely confounded. There was no longer any means for the fish to get to their spawning areas further upstream. An innovative fish lift was constructed in 2009 to allow the fish to be collected and transferred over the dam wall.