A pioneering flood management project in the Scottish Borders has been chosen as the only UK-based UNESCO Ecohydrology Demonstration Site and the project will now be included in the organisation's Intergovernmental Hydrological Programme (IHP).
Developed by Tweed Forum in conjunction with Forest Carbon and several other partners; the project looked to use Natural Flood Management methods to slow the progress of water downstream. The aim was to reduce the severity of downstream flooding events, with the hope that there would be additional benefits such as biodiversity uplift and climate mitigation.
A tributary of the Tweed river situated upstream of Peebles, a large stretch of the Eddleston water was straightened, channelised and embanked in the early and mid-19th Century to enable the building of a road. This was in addition to the loss of native woodland cover, land drainage and afforestation with non-native conifers that had already occurred. These actions led to its connection with its flood plain being lost and a large decrease in the time it took surface water upstream to be transmitted downstream, leading in turn to a greater flooding risk in Eddleston and Peebles. In addition, all of the above actions had the effect of removing or damaging habitats for plants and animals such as salmon, trout, otters and lamprey.
Recognising the need to reduce flood risk and restore the Eddleston Water for the benefit of the local community and wildlife, a partnership initiative led by Tweed Forum was formed. Tweed Forum, and in particular the recently retired Hugh Chalmers, were instrumental in locating and designing projects for maximum NFM benefits; not to mention engaging landowners and persuading them to proceed.
To date, the project which is in its 13th year, has planted over 330,000 trees, created 38 new ponds and installed 100 log structures to help to slow excess water and direct it into surrounding land. This work in addition to re-meandering and bank removal efforts, has led to a delay of up to seven hours in the timing of river peaks allowing crucial preparation time in the event of floods.
Wildlife has also benefited with increased river length and woodland creation providing habitat for charismatic fauna such as otters, kingfishers and salmon. Environmental-DNA analyses show the Eddleston ponds also provide new habitats for aquatic invertebrates from over 50 families, including 25 high scoring water-quality indicator species of mayfly, stonefly and caddisfly.
Forest Carbon was able to generate essential funding for six new woodland sites within the larger project by providing a route to carbon finance. These projects, validated by the Woodland Carbon Code, cover 88 hectares. They will sequester in excess of 32,000 tonnes of carbon dioxide over their lifetimes and enhance wildlife habitats. In addition they will provide shade and improve water quality for the benefit of spawning fish.