Reservoir formed by damming the Nant Lletwys, constructed in 1818 for the nearby smelting works (nprn 91752). The water was later used by a nearby woollen mill (nprn 91750) from about 1820.
(Source: C.C.Green, The Vale of Rheidol Railway, Wild Swan, 1986).
B.A Malaws, 13 October 1999.