River Misbourne

The River Misbourne is a chalk river flowing for 17 miles through the Chilterns AONB and the towns Missenden, Amersham, and the Chalfonts, before joining the River Colne just beyond Denham.

Problems faced by the River Misbourne

The river channel has been modified extensively including straightening of sections, and raising the channel to form mill leats. Artificial lakes have also been constructed at some locations along the river, for example at Shardeloes Lake located 2km upstream of Amersham in mid catchment.
The river also loses water along some reaches, becoming perched or dry for extended periods depending on climate conditions. This is related to changes in chalk geology and the natural difference between the bed level and chalk water table. Historic physical modifications to the river may exacerbate this issue further.

Case Study: Denham

The lower Misbourne was overwide, over-shaded and uniform with little habitat diversity. There was also a need in improving access to the river for the many children visiting the Colne Valley Park Visitor Centre for river dipping.
A large project was carried in out in partnership between the Environment Agency, Berkshire, Buckinghamshire, and Oxfordshire Wildlife Trust (BBOWT), Groundwork south and the landowners in 2018.
As part of the restoration work tree thinning was carried out to increase light into the river corridor. Volunteers used brash berms to increase the diversity of the river channel, and tree hinging was used to increase bank defence, and catch sediment. Other woody habitat features were implemented to increase flow diversity in the channel by creating scour pools.
To improve the amenity value of the river, a large formalised access beach was created, so that local children can now safely enjoy the river. The river bank was re-graded to a uniform slope over a 20m length, and a base was laid down and then topped with rounded gravel. Other informal access points to the river were blocked off using natural material which has made the river more resistant to erosion.

If you’d like to find out even more, follow the link to the Catchment Partnership website for the River Colne Catchment or view the management plan for the River Misbourne.

Design by LTD Design Consultants and build by Garganey Consulting.