Buckinghamshire Council Culvert Policy

Watercourses fulfil many roles in today’s environment. They provide drainage for developed and agricultural land and can be vital water resources, while some also have important recreational value. They are important features of the landscape and provide habitats for a wide variety of wildlife. It is therefore important that watercourses and their associated habitats are protected and enhanced for the benefit of present and future generations.

Buckinghamshire Council considers it beneficial for watercourses to remain open wherever possible for both flood defence and environmental purposes. Culverting can exacerbate the risk of flooding, increase maintenance requirements and create difficulty in pollution detection. It also destroys wildlife habitats, damages a natural amenity and interrupts the continuity of a watercourse.

In considering any development proposals, our objective is to retain open watercourses with a corridor of open land on both sides. This maintains a conveyance channel for flow and creates a valuable environmental feature which can enhance the site and be easily maintained. We will also encourage developers to incorporate existing open watercourses or create new ones, within their design. Such features are of particular importance to wildlife by providing valuable open land in developed areas. Where possible, the removal of culverts will be encouraged to restore a more natural river environment and reduce flood risk as well as maintenance requirements.

Nevertheless, we understand that there may be cases where culverting is unavoidable for example, short lengths for access purposes or where infrastructure crosses watercourses. In such cases the length involved should be restricted to a minimum, the hydraulic and environmental design assessed, and appropriate mitigating enhancements to the surrounding environment included.

However, culverting will not be considered until other options have been thoroughly explored, for example:

• clear open span bridges with existing banks and bed retained
• revision of site layout to incorporate an open watercourse
• diversion of the watercourse in an environmentally sympathetic channel and corridor
• constructing a ford, where appropriate.

Definitions of Ordinary Watercourse, Main River, bridge and culvert can be found in Paragraph 10 of this policy.