River Lark

River Lark
The river near Icklingham
Location of the river mouth just outside Suffolk
Location
Country	England
Physical characteristics
Source	Whepstead
• coordinates	52°11′18″N 0°39′09″E / 52.1883°N 0.6525°E / 52.1883; 0.6525
• elevation	104 m (341 ft)
2nd source	Bradfield Combust
• coordinates	52°10′39″N 0°43′57″E / 52.1775°N 0.7325°E / 52.1775; 0.7325
• elevation	65 m (213 ft)
Mouth	Littleport, River Great Ouse
• coordinates	52°26′07″N 0°18′43″E / 52.4352°N 0.3120°E / 52.4352; 0.3120
• elevation	0 m (0 ft)
Length	57 km (35 mi)
Basin features
Tributaries
• left	River Linnet

v t e River Lark
Legend
River Great Ouse former  A10  bridge Pumping Stn Ely to Norwich Railway bridge Pumping Stn  B1382  Prickwillow Bridge Museum of Fen Pumping Engines Lark Engine PS and Engine Drain Soham Tunnel Drain Pumping Stn Pumping Stn Pumping Stn 26 Isleham weir and lock River Island Marina Lee Brook Limit of navigation Judes Ferry Bridge Kings Staunch Bridge Mill  B1102  Mildenhall Bridge  A11  Barton Mills Bridge Cut-off channel Tuddenham Mill Stream Weir Temple Br (Icknield Way Path) Icklingham lock and Mill Farthing Bridge  A1101  Road bridge West Stow bridge 7 lock and Chimney Mill 6 Weir (Hengrave Lock) 5 Weir (Ducksluice Farm Lock) Fornham bridge 4 Weir (Fornham Park Lock) Fornham Dock (original terminus) 1  B1106  Tollgate Bridge (site of lock)  A14  Road bridge Northgate Dock Bury St Edmunds station Eastgate Bridge (proposed terminus) River Linnet  A134  Road bridge to source

The River Lark crosses the border between Suffolk and Cambridgeshire in England. It is a tributary of the River Great Ouse, and was extended when that river was re-routed as part of drainage improvements. It is thought to have been used for navigation since Roman times, and improvements to its navigability were made in 1638 and in the early 18th century, when locks and staunches were built. Special powers to improve the river from Mildenhall to Bury St Edmunds were granted by statute (River Lark Act 1698). The upper terminus was on the northern edge of Bury St Edmunds, but a new dock was opened near the railway station after the Eastern Union Railway opened its line in 1846.

The navigation was officially abandoned in 1888, but despite this, commercial use of the river continued until 1928. Following an acquisition by the Great Ouse Catchment Board, locks at Barton Mills and Icklingham were rebuilt in the 1960s, but were isolated when the A11 road bridge was lowered soon afterward. It now has one operational lock at Isleham, and can be navigated to Jude's Ferry.

Water quality in the river was generally moderate in 2016, although there was a section where the quality was bad, the lowest rating given by the Environment Agency, who monitor English rivers. The river hosts a large population of signal crayfish, an invasive species which has increased as the eel population has diminished.