Cairn Beck NFM project
Part of project: Natural flood management
The project has shown how multiple, different NFM measures can work together at a catchment scale. A 5km reach of connected NFM measures and habitat improvements has been created along the Cairn Beck river. These NFM measures have improved biodiversity and in-stream habitat, led to better water quality, increased carbon sequestration and created shelter for livestock.
This project started in August 2018 and was completed in March 2021. The project involved identifying and implementing natural flood management (NFM) measures throughout the Cairn Beck catchment. The project was funded through the EA as part of the national Defra NFM project.
To start off with the project involved scoping and landowner engagement to identify suitable NFM options and the development and implementation of the monitoring strategy to measure the effectiveness of these measures, including the installation of rain gauges and water level measuring devices.
Throughout the 3-year project the following measures have been implemented:
8 leaky dams were installed on Newbiggin Beck and we modified 15 leaky dams that we installed in 2016 in order to improve their performance as NFM measures.
Riparian buffer strips
A total length of 1.7km of riparian buffer strips have been installed at 4 different sites. Riparian buffer strips have many multiple benefits from improving water quality, enhancing biodiversity and habitat as well as NFM benefits.
3 ponds have been created holding a total of 116m3 of water. The ponds provide NFM benefit as have the capacity to fill up during high rainfall events and slowly drain away enabling water to be held back in the landscape. Additionally, the ponds have great habitat benefit, the landowner of one site recently told us they saw a fish in the pond despite it not being connected to the river and only been completed in September 2020.
We completed a river restoration project which involved restoring a section of 200m straightened channel to re-instate meanders, bars, riffles and pools along with secondary and tertiary channels and ponds. This has created more storage of water on the floodplain as well as slowing the flow of the water in the channel. The new channel has been very successful in high rainfall events enabling more water to be stored and slowing the flow travelling downstream.
A total of 1.63km of kested hedgerows have been created at 3 different sites. Kested hedges help reduce the volume of runoff in the fields down to the river by intercepting surface-water flows, rainfall and promoting infiltration to the soil.
The monitoring aspect of the project is critical in understanding the success of these measures, building knowledge of their effectiveness and supporting future NFM work. This includes:
Leaky dams site:
Four water level measuring devices have been installed at the leaky dams site:
- Two bracketing the entire site i.e. one at the upstream end and one at the downstream end of the series of leaky dams
- Two on one leaky dam i.e. one directly upstream and one directly downstream of one dam
Plus a tipping bucket rain gauge to record rainfall events.
Additionally, a PhD and an undergraduate student from Newcastle University are carrying out their research projects on this site.
Two water level measuring devices at the upstream and downstream ends. Students from the University of Salford will be assessing the difference in hydrographs and typography from drone surveys.