Плотина Катаракт: История и особенности строительства

The Cataract Dam is a heritage listed dam in Cataract (formerly Appin), New South Wales, Australia, provides water to the Macarthur and Illawarra regions, the Wollondilly Shire, and metropolitan Sydney. It is one of four dams and weirs in the catchment of the Upper Nepean Scheme. Completed in 1907 under the supervision of Ernest Macartney de Burgh, the dam is currently owned by Water NSW, an agency of the Government of New South Wales. The dam was listed on the NSW State Heritage Register on 18 November 1999.

A gravity dam with an unlined side spillway extending from the left abutment, it is tall; long; and it 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 downstream face is of mass poured basalt concrete, with a basalt facing. A readily accessible source of suitable rock was located at Sherbrooke, situated near the top of Bulli Pass. To transport the basalt from the quarry to the dam construction site, a 2ft gauge steam tramway, long, was constructed. The dam is built of cyclopean masonry, composed of sandstone blocks weighing from These were quarried at the site and bedded in cement mortar. The vertical joints were filled with basalt or sandstone concrete. The upstream face consisted of basalt concrete moulded blocks set in a cement mortar. The downstream face was of basalt concrete, thick in the lower section and thick in the upper section. There were two lines of diameter pipes which passed through the dam and discharged water into the Nepean River. The flow is controlled by a Larner Johnson needle valve. The dam wall was given a decorative finish. The upstream parapet was castellated with sandstone blocks while the top of the downstream wall was corbelled in concrete. In approximately the midsection of the dam stands the valve house. This is finished in quarried sandstone blocks with ashlar coursing. It features a steeply pitched slate covered pipped roof topped with finials and gables at either side.

The Upper Nepean Scheme was commenced in 1880 after it was realised that the Botany Swamps scheme was insufficient to meet Sydney's water supply needs. The Nepean project consisted of the construction of a weir across the Nepean River to divert of the rivers Cataract, Cordeaux, Avon and Nepean, to the Prospect Reservoir. The land Macquarie intended to study lay between the Nepean and Georges Rivers. There had been no identification of the land which ran as far south as the Cataract River and was bounded on the west by the Nepean River and on the east by the Georges River. On completion of his survey, this area reminded him so much of his own (home) district in Scotland that he called it the Airds district. Some time later he named the section south, including Mount Gilead, Appin. The northern boundary of the Appin district is the property known as Mount Gilead, which was granted to Reuben Uther. Some years later it was purchased by a Sydney businessman, Thomas Rose, who was credited with building the first dam for water conservation in the colony (here). This was carried out very thoroughly and with great expense. He was generous with the water conserved and allowed his neighbours to water their stock in very dry times. On the southern side, Mount Gilead was joined by the Hume (family) properties, Beulan and Meadowvale (formerly Rockwood). These and others such as Fairview, Blossom Lodge, Mount Carlon and the big poultry farm conducted by Ingham enterprises are all on the western side of the Appin Road. Opposite the last property is one known as Kildare, one of the pioneer homes of the Irish Dwyer family. On its southern boundary, it was joined by Broughton's Lachlan Vale (the first land grant in the area). That property in turn joined John Kennedy's original grant, that he named Teston. In later years, different owners added to it, growing the property to over This acreage on the south side joined the area known as Mount Brittain of , a grant to William Sykes. With further grants it became over
Further south, Mount Brittain joined a grant to James Jordan, the southern boundary being the Cataract River and here was the place known as Jordan's Crossing, where the road from Mount Keira (now Picton Road) crossed the river. There were a number of small grants on the way back to Appin such as those of John Firth, Edward McGee, John Trotter, Nicholas Bryan and Matthew Pearce and several others. Laurence D'Arcy was also granted joining Jordan's and named it Spring Valley. Appin has two solidly built stone churches, St. Bede's Roman Catholic and St. Mark's Anglican. Both were built about the same time, 1840–41 and have stood the test of time. Both are equipped with very good bells. The population of Appin was quite large: in 1825 the number was 562. A large number of farmers were engaged in wheat, barley, corn and vegetable growing for the Sydney market.

The Cataract Dam is built of cyclopean masonry composed of sandstone blocks, weighing from , quarried at the site and bedded in a cement mortar. The vertical joints were filled with basalt or sandstone concrete. The upstream face consisted of basalt concrete moulded blocks set in a cement mortar. The downstream face was of basalt concrete, 6 feet (2 m) thick in the lower section and 3 feet (1 m) thick in the upper levels. There were two lines of diameter pipes which passed through the dam and discharged water into the river. The flow is now controlled by an AGE Ring Faulkner valve. There is also a Ring Faulkner Gate Valve and a Fixed Crane Dispersion Valve.