cbec was contracted by Dundee University and the Tweed Forum to provide the joint benefits of improving the ecological status (through river restoration) and natural flood management of Eddleston Water, a tributary of the River Tweed in the Scottish Borders
We initially conducted a geomorphic assessment in 2010 to assist in developing an ecologically sensitive catchment management plan and sustainable flood alleviation scheme in the watershed. A continuous geomorphic survey (including a quantitative stream power assessment) of 13 km of the river was conducted, identifying a number of potential reaches for restoration and floodplain inundation.
Subsequent work involved using 1D and 2D hydrodynamic models to guide specific restoration designs across the catchment, which have included re-meandering of historically straightened sections of the river. These assessments led to developing detailed designs for three reaches of the river. Construction of these was undertaken in July 2013 (Cringletie), September 2013 (Lake Wood) and September 2014 (Shiphorns). A further phase (re-meandering the section of channel between Lake Wood and Cringletie, resulting in a continuous 2.1-km-long section of restored channel) was undertaken in 2016 (Milkeston) and is now complete.
At the prioritised sites, cbec carried out topographic surveying, application of geomorphic stable channel theory and 2D hydrodynamic modelling phases of the work to determine the optimal design for the three reaches. A series of conceptual visualisations were produced, followed by detailed AutoCAD (Civil 3D) engineering design drawings and an associated method statement to meet the Scottish Environment Protection Agency’s licensing requirements. We supported the Tweed Forum’s stakeholder engagement and consultation work throughout the projects. Furthermore, these restoration projects have contributed to work led by the Tweed Forum on the wider Tweed system being awarded the 2015 UK River Prize and the Nigel Holmes Trophy.