Identifying and protecting river habitats
Many watercourses are surveyed and information recorded prior to works by means of either a walkover survey, or a River corridor survey. The latter is the more detailed and comprehensive form of survey, and is employed on rivers of high conservation value. This information is used to determine the most suitable methods of river management.
The following are often taken into account:
- Birds, mammals, fish and invertebrates live within the river corridor. Care is taken to minimise the disturbance to nature by working outside the breeding and spawning seasons
- River banks provide habitats for a range of plants and animals. Work is confined to one bank only, leaving the other bank untouched
- Trees and bushes provide habitat for birds and mammals, and shade for fish. Trees are retained by working round them; if necessary, branches are lopped or coppiced, thus retaining the original tree
- Deep hollows and flowery grassland are important habitat for wildlife. Spoil material is disposed of carefully and not spread in hollows or on species rich grassland
- Natural materials provide alternative habitat for wildlife. Stone wood and willow are used, where appropriate, for bank protection
