1) Found in early documents in connection with water mills. It is likely to refer to the wooden trough which conveyed water from the dam to the water wheel, deriving power from the ‘fall’.
1349-50 Et tam pro emendacione del Falltrogh simul cum stapulis et bordis, Hartshead
1462-3 2 trees from Rothwell Park for the fulling stock and faltrough . It occurs as Faltrogh in Rothwell in 1292, listed among the minor place-names.