- On 6th April 2017
- In Ecology, Water Management
- By William Coulet
On the 4th and 5th April, Exo Environmental attended the River Restoration Centre’s (RRC) 2017 annual network conference in Brighton, to see examples of how those upstream rivers are restored and “Address Uncertainty”, the subject of this year’s conference.
The RRC17 did a great job of hosting the event, with a great attendance from a range of stakeholders: natural and social scientists, river engineers, planners, practitioners, consultants, contractors, agencies, environmental economists, trusts, NGOs, water companies, local authorities, landowners, and many others with an interest in restoring rivers for both people and wildlife.
Whilst there was overlap between Exo’s expertise and that on show at RRC17, the event also provided us with a great platform to exchange knowledge, discuss approaches and network with others who share our philosophy in “Working with Nature” and promoting the beneficial use of dredged materials through restoration works.
William was also invited to present previous work of Exo’s, involving the dredging and dispersal of sediments from within Waterside Marina, Essex, back in early 2016. This project involving the removal of 11,000cu.m of accumulated sediments aimed to showcase the advantages of following an adaptive management approach during dredging and restoration works to ensure projects are robust to uncertainty. See here for the Central Dredging Associations (CEDA) position paper and further reading on adaptive management (LINK).
In addition to the presentation, William was part of a group of delegates who managed one of the workshops promoting knowledge exchange at the event. “Managing Silt: Muddy Waters or Clearwater Revival” focused on two key areas of silt management: how material is generated from our own activities; and how to efficiently remove silt from watercourses in order to improve habitats and aid the removal of barriers. Participants were encouraged to discuss various approaches to overcoming silt accumulation in watercourses and what necessary analysis needs to be carried out to avoid the spread of contaminated sediment. Ways to mitigate sediment problems included farmer incentives and advice; buffer strips and tree planting; surface water management plans; natural flood management; improved farm access such as tracks; formalising access for the public; and engaging with stakeholders to raise awareness of the issues.
Whilst William presented and managed in the classroom, Will attended the Woodsmill Stream restoration site in full view of the Sussex sun! This site is a tributary of the River Adur in Sussex and runs through the Sussex Wildlife Trust Headquarters. Previously a channelized section to supply the mill on site, a project to provide fish passage to the headwaters of the system past the mill stream as well as restoration of a 360m section of watercourse was led by the Environment Agency, in conjunction with the Sussex Wildlife Trust. Restoration in 2010.
A new meandering course was established which created a significantly wider flood corridor as well as a low flow channel in the lowest part of the floodplain. The stream was designed to freely adjust following construction. Features that were installed as part of the scheme included riffles, deeper bends, meander cut-offs, ford and woody debris features. Much of the old course was left to form a ribbon backwater feature. The fish pass was also constructed on private land further upstream to provide free passage for sea trout to the headwaters of the system.
Since the works were completed, a significant number of sea trout have been recorded spawning in the headwaters since the overall project was constructed. The restored river also forms an integral part of the Sussex Wildlife Trust’s education and schools programme, with regular visits to learn about natural river features and wildlife. Certainly a restoration project success!
All in all, a great event. Congratulations also to the River Avon Restoration Project on winning the Nigel Holmes Trophy for their excellent work and congratulations to all the other finalists! See you all next year.