River Glaven

To improve the in-river habitat upstream from Letheringsett Ford; to re-connect the river and floodplain; and to develop an experience base which would serve the River Glaven Conservation Group (RGCG) well on other projects.

Natural Flood Management Measure: 

Re-meander channelised section and floodplain storage:

The main works carried out in the river were the introduction of 6 riffle areas (total length 65m), two of which were dual function as cattle crossings; two lengths of river narrowing (10m and 13m); the creation of 3 mid-stream islands; and 9 lengths of tree trunk as large woody debris flow deflectors at a spread of points. In addition 700-1,000 tonnes of spoil was removed along 130 m of a meadow. The re-profiled bank was protected from erosion by use of hazel revetment & coir matting. The 6 sycamore trees felled on site provided the large woody debris requirements. The posts, faggots, batons and brash used for river narrowing, island construction, and the bank protection work were produced by coppicing hazel trees on site or nearby. The stone and gravel came from local sources, both less than 3 miles from the site, as did the gravel. Large stone was recovered by hand from the spoil, which was later spread over an arable field.

Flood Receptors: 

To improve the in-river habitat upstream from Letheringsett Ford; to re-connect the river and floodplain; and to develop an experience base which would serve the River Glaven Conservation Group (RGCG) well on other projects.

Physical Environment: 

The River Glaven is a small chalkstream in north Norfolk. The river flows some 17 km, before finally entering the sea at the tidal sluice at Cley. The gradient is steep for a lowland river. The river and meadows are valuable for wildlife.

Site Ownership: 
Unknown (likely to be varied)
Start Date: 
1 May, 2006
End Date: 
1 November, 2006
Project Cost: 
£20,000
Feature Cost: 
Unknown
Additional Information: 

This case study is an excellent example of a successful community driven project. The RGCG, through their time and enthusiasm, have implemented a range of effective restoration techniques, the impacts of which are already apparent – the modified reach is much more lively with greater variations in flow patterns and water depth. The RGCG plan to study the effects of the restoration works on aquatic plants, native crayfish, water vole and a number of fish species.

Information Source: 

River Restoration Centre, A River Glaven Restoration Project; Techniques: Introducing variation in river depth, width & flow; & re-connection of a flood plain