The river is formed from head springs which rise on the western side of Wadeford which join with waters from Combe St Nicholas. It flows in a westerly direction past Pudleigh and Nimmer to reach Hornsbury Mill. After a short distance it turns in a northerly direction past Peasmarsh, Donyatt, Ilminster, Puckington, and Isle Abbotts, before joining the River Parrett just above Hambridge . The river flows for an approximate distance of 14 miles and in its first six miles it falls 250 feet, but then meanders sluggishly, with a fall of only 80 feet, to its confluence with the Parrett. On it's journey from source to mouth it is joined by the tributaries, the River Ding and the Fivehead River with Venner's Water, together with several un-named brooks, which drain the north-east flanks of the Blackdown Hills. On the north-west side the tributaries of the Dowlish Stream with Stretford Water and the Wall Brook drain Windwhistle Hill and Sprays Hill and the hill spur above Whitelackington. Approximately 1 mile before the rivers join with the Parrett it is joined by the Westport Canal.