This project is another in Forest Carbon's partnership with the Tweed Forum - aimed at not only reducing CO2 but also mitigating flooding and improving water quality in the Tweed catchment.
Natural flood management
In September 2008 and July 2009 prolonged and intense rainfall caused major flooding in the north-east Cheviots, on the Scottish/English border, with significant damage to infrastructure, agriculture, woodland and communities as far south as Morpeth. A review was commissioned by the Tweed Forum – a charitable body, backed by a broad public and private membership, with a brief to co-ordinate actions that lead to the sustainable management of the river and its catchment – into how best to prevent and ameliorate the recurrence of such events. The River Till and its tributaries, all in turn flowing into the Tweed, were the worst affected by the floods and the planting carried our by the Forum and Forest Carbon is part of the solution identified for those tributaries. There is a considerable body of practical knowledge and research evidence pointing to riparian woodlands as an effective means of flood management, through the following means:
- By reducing peak flood flows through woodland soil’s ‘sponge’ effect
- By reducing run-off through evaporation of water intercepted by the woodland canopy, or through transpiration by tree roots
- By slowing run-off through damming caused by Woodland debris
- By reducing the amount of silt that reaches rivers, thus enhancing their capacity, and by stabilising river banks
By reducing the amount of water reaching the watercourses, and then lengthening the period over which the surge of water is delivered to a watercourse, flooding is either prevented altogether or reduced. Upstream flood management is also very cost-effective – removing the need for difficult to implement flood protection, or the expensive consequences of flooding, in urban areas.
Riparian woodland also make the following important contribution to woodland and river biodiversity:
- Base flows of rivers are maintained – important for fish survival in the summer
- Dappled shading of streams – keeps summer water temperatures low
- Pollutants are filtered from entering watercourses by trees
- Woodlands provide habitat and habitat connectivity
There are no public access limitations at the sites.