South Cumbria Rivers Trust (SCRT) have just completed an exciting urban Natural Flood Management (NFM) project in the heart of Kendal, South Cumbria.
We have been scoping and developing the project for over two years, as part of the Environment Agency, DEFRA funded, Cumbria NFM programme. Now with all permissions in place, practical interventions are due to start the beginning of August. The site has been offered by South Lakeland District Council (SLDC), the landowners, as a candidate site for the research, development and demonstration of NFM techniques. The proposals have been developed by SCRT and supported by The Friends of Nobels Rest, Environment Agency (EA), SLDC, Catchment Designs Ltd, RG Parkins and Cumbria County Council.
The Kendal Town View Fields project is a fantastic opportunity for the demonstration of NFM techniques in a townscape setting. To compliment the work we also plan to deliver interpretation and education activities to show how NFM techniques can deliver multiple benefits, such as restoring natural hydrological processes and biodiversity.
What has been done?
The site is being used to test how effective NFM techniques are in urban areas. We have done a number of rural NFM works, which you can view here.
The project has opened up approx. 90 metres of culverted watercourse running through the site.
A meandering stream has been created, running into bunded wetland areas with stormwater attenuation capacity. Attenuation capacity refers to the storing of storm water in high flows to allow for the slow release of water through the ground or by other means. In this example, it then reconnects to the culvert downstream.
We have installed two Leaky Dams to demonstrate their design to store and slowly release flood water onto during flood events. Again, we have a number of examples of different Leaky dams we have used in recent NFM projects.
Finally, we will be planting native tree species and wetland species in the near future that will provide amenity, aesthetic and biodiversity benefits.
- De-culverting and de-commission of the existing stone-walled culvert through the site,
- Creation of a new open channel through the site, with reduced slope in comparison with current culverted reach,
- Creation of bunds and leaky dams using natural materials (earth and timber), to temporarily store and attenuate peak flows from the watercourse during storm events,
- Protection of the new channel bed and banks with erosion control measures,
- Construction of a formal headwall to collect and convey flows back into the existing culvert downstream of the site,
- Construction of an impermeable bund to reduce the likelihood of exceedance flow entering neighbouring land,
- Plant trees and encourage grass land habitats through planting conservation grass seed mixes
These works will serve multiple purposes; restoration of a watercourse, researching the effectiveness of NFM techniques, testing the viability of using NFM techniques in urban areas, reducing the peak flow during targeted storm events and providing a public demonstration of NFM.
Catchment Designs Ltd were the contractors that carried out the works on our behalf.