The Sowy River at Stathe
|Mouth||King's Sedgemoor Drain|
|Length||12 km (7.5 mi)|
The Sowy River is an artificial drainage channel in Somerset, England.
It is a 7.5-mile (12.1 km) embanked channel which starts at Monks Leaze clyce below Langport, and carries excess water from the River Parrett to the King's Sedgemoor Drain, from where it flows to the estuary by gravity, rejoining the Parrett near Dunball wharf. Construction of the channel, together with improvements to the King's Sedgemoor Drain and the rebuilding of the clyce at Dunball, to create a fresh water seal which prevents salt water entering the drain from the river, cost £1.4 million, and was completed in 1972. The scheme has resulted in less flooding on Aller Moor.
During 2009 and 2010 work was undertaken to upgrade sluice gates, watercourses and culverts to enable seasonal flooding of Southlake Moor during the winter diverting water from the Sowy River onto the moor. It has the capacity to hold 1.2 million cubic metres as part of a scheme by the Parrett Internal Drainage Board to restore ten floodplains in Somerset. In spring the water is drained away to enable the land to be used as pasture during the summer. The scheme is also used to encourage water birds.
The Environment Agency measure water quality of the river systems in England. Each is given an overall ecological status, which may be one of five levels: high, good, moderate, poor and bad. There are several components that are used to determine this, including biological status, which looks at the quantity and varieties of invertebrates, angiosperms and fish, and chemical status, which compares the concentrations of various chemicals against known safe concentrations. Chemical status is rated good or fail.
The Sowy River and the King's Sedgemoor Drain are assessed as a single unit, and water quality was as follows in 2015.
|Section||Ecological Status||Chemical Status||Overall Status||Length||Catchment|
|King's Sedgemoor Drain - Henley Sluice to mouth||Moderate||Good||Moderate||17.3 miles (27.8 km)||44.63 square miles (115.6 km2)|
- Otter, R. A. (1994). Civil Engineering Heritage: Southern England. Thomas Telford. ISBN 0-7277-1971-8.
- "The Parrett Catchment Water Management Strategy Action Plan" (PDF). Environment Agency. 2002. p. 15. Archived from the original (PDF) on 19 March 2009. Retrieved 28 December 2009.
- "Southlake Moor restored to floodplain by drainage board". BBC. 17 January 2011. Retrieved 19 January 2011.
- "Southlake Moor Favourable Condition Project Newsletter 2: Autumn 2010" (PDF). Parrett Drainage Board. Retrieved 19 January 2011.
- "Glossary (see Biological quality element; Chemical status; and Ecological status)". Catchment Data Explorer. Environment Agency. Retrieved 17 May 2017.
- "King's Sedgemoor Drain - Henley Sluice to mouth". Catchment Data Explorer. Environment Agency.