Gwydir River /ɡhwˈdˈər/, a major inland perennial river of the Barwon catchment within the Murray-Darling basin, is located in the Northern Tablelands, North West Slopes, and Orana districts of New South Wales, Australia. The flow of the river is impounded by Copeton Dam, with storage used for town water supply, stock, domestic use and irrigation. The Gwydir River below Copeton Dam provides some of the wildest whitewater rafting available in Australia. Before the construction of Copeton Dam and much diversionary work, the Gwydir River flowed into the Gingham and Lower Gwydir Wetlands.