Upper Canal System
The Upper Canal System, also called the Southern Railway Aqueduct and the Cataract Tunnel, is a heritage-listed operational gravity-fed aqueduct that supplies some of the potable water for Sydney, in New South Wales, Australia. The aqueduct comprises 54 kilometres (34 mi) of open canals, tunnels, and closed pipelines that connect the Upper Nepean Scheme with the Prospect Reservoir.