tall, long and holds of water. Cataract Dam was the first dam built in the Upper Nepean Scheme, it was also first dam in Australia to use pre-cast moulded concrete blocks for the upstream face of the dam. The core of the dam consists of large sandstone blocks, quarried onsite and cemented together. The downstream face is of mass poured basalt concrete, with a basalt facing. A readily accessible source of suitable rock was located some distance away at Sherbrooke, also known as Ferndale, situated near the top of Bulli Pass. To transport the basalt from the quarry to the dam construction site, a gauge steam tramway, long, was constructed. Dam construction began in 1902 and was completed in 1907, and the spillway was widened in 1915. Ernest Macartney de Burgh was the supervising engineer for the project from 1904. Poet Banjo Paterson wrote a satirical ballad "The Dam that Keele Built" about the politics behind the construction of Cataract Dam. Cordeaux Dam The Cordeaux Dam is a heritage-listed arch dam across the Cordeaux River with an unlined side spillway on the left abutment. It is high, long and creates a reservoir which holds . Construction began in 1918 and was completed in 1926 at a cost of A£945,000. The wall consists of large sandstone blocks, quarried onsite and cemented together, faced with a combination of bluestone and sandstone concrete. The dam featured a number of improvements in design and construction on the earlier-completed Cataract Dam. These included contraction joints between units of construction placed at intervals of ; inspection galleries at upper and lower levels, together with piping for registering any ground water pressure. The blue metal used in the construction of the dam was supplied from the Government Quarries at Kiama and brought by rail to Douglas Park. From here it was conveyed by aerial ropeway across the Nepean Gorge to an interchange on the eastern side where the material was transferred to a gauge steam tramway to a point adjacent to the dam site. Avon Dam The Avon Dam is a heritage-listed arch dam across the Avon River; it is tall, long and its reservoir holds . It has the largest capacity of all the dams in the Scheme. Construction of the heritage-listed dam wall began in 1921 and was completed in 1927 at a cost of A£1,047,000. The dam construction and materials are the same as