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Sensitive techniques for managing vegetation (bed and banks)

River banks and beds and channel margins support a range of important habitats for plants, invertebrates and other aquatic organisms. If left unmanaged, plant growth can become an issue by:

  • Choking river channels - reducing flow conveyance and increasing flood risk
  • Destabilising artificial banks through root penetration
  • Reducing the amount of light that reaches the river and reducing habitat diversity

It is therefore important that vegetation that grows on the river bed and banks is managed carefully so as to not damage important habitat. River managers must therefore select management techniques which preserve as much of these natural habitats as possible (whilst still fulfilling their management objectives).

Techniques

There are a range of techniques that can be used to implement this activity, depending upon the type and maintenance requirements of the water body in which it is going to be applied:

  • Retention of marginal habitats (including fallen trees and branches) unless they compromise flow conveyance
  • Use of sensitive vegetation management techniques which do not impact upon marginal habitats. These could include hand-picking or selective cutting of in-channel and bankside vegetation, coppicing or pollarding trees instead of felling them, only cutting the centre of the channel, and using herbicides to control vegetation instead of cutting
  • Use of boat-mounted vegetation cutting or herbicide spraying equipment to allow work to be undertaken in the main channel without disturbing the margins and banks
  • Change the frequency of maintenance activities, so habitats have time to recover before they are disturbed again

Benefits

Maintenance activities which minimise the disturbance to bed and bank habitats can deliver a wide range of benefits, including:

  • Direct ecosystem benefits associated with the retention of bed, bank and marginal habitats and the maintenance of biodiversity
  • Natural erosion protection
  • Aesthetic improvements to the watercourse, by providing a more natural look
  • Benefits for any commercial fisheries in the watercourse, by providing natural habitats for fish and their prey
  • Reduced costs of appropriate vegetation management techniques

Case Study Benefits

This diagram displays a comparison of benefits scores (using a high-level ecosystem service assessment methodology) associated with the techniques used in each case study. More details on the methodology can be found here

Case Studies

These case studies are examples of how this environmental improvement could be delivered. Some are delivered through FCERM (EA) funding and some by other stakeholders (local councils, IDBs, developers, etc.)

Cost bandings are as follows:

  • £ = £1k-£10k
  • ££ = £10k-£50k
  • £££ = £50k-£100k
  • ££££ = £100k-£500k
  • £££££ = £500k+

An explanation of the headings in the case studies and the ecosystem services compass diagrams can be found: HERE

Other relevant case studies:

WFD Terminology

Throughout this best practice, 'environmental improvements' refer to WFD 'mitigation measures'. The names of some mitigation measures are different in England, Scotland and Northern Ireland.

This mitigation measure is named:

  • Appropriate vegetation control technique (England)
  • Replanting native vegetation along the bank and bank top (NI)
  • Branches can be cut back to thin out the vegetation and reduce channel shading (NI)