Our Summer Placement volunteer Jess spent a day with our catchment officers in the upper Severn working with local young people to install natural flood management features. In this article, she tells us what the day entailed…
Students at Llanfyllin High School recently took part in catchment restoration along the River Abel. As part of the completion of their Welsh Baccalaureate, they installed three leaky dams to help ‘slow the flow’ of winter flood waters. they were joined on the day by part-time summer placement volunteers, who have been assisting with river conservation tasks around the region.
‘Leaky dams’ are built close to watercourses, in areas that regularly become flooded after heavy winter rainfall. They work by reducing the flow rate of flood water as it moves through the catchment, preventing large flash floods from occurring further downstream.
To start the day, project organisers Dewi Morris and Charlotte Davis gave a talk on the benefits of installing leaky dams, followed by a tour of the site at the edge of the school grounds. Potential dam sites were identified and animal tracks were spotted before branches of various sizes were collected. Since some larger branches were needed for the dam, this included a lesson in tree felling from Dewi.
The students worked well as a team and in just a few hours, the wood to be used had been collected and cut to size, and the area above the dam was cleared of debris. Live willow sticks were pushed into the ground to fill the flow paths of the flood water. To build a dam, pairs of posts were installed to place the branches between. Large branches were placed at the bottom to prevent the dam from becoming blocked, smaller branches in the middle followed by more large branches to weigh the pile down. Wire was stretched across the top to prevent the wood from being washed away during high flow.
Dewi, SRT’s Catchment Restoration Officer said: “The students all worked really well together survey and find the best place to build a leaky dam. They built it across a derelict outlet for a small reservoir for the old boating lakes (no longer there) next to their High School. A perfect place to “slow the flow” of the Abel Brook before it flows under the town of Llanfyllin into the river Cain.”
This event is part of a wider project currently being delivered by Severn Rivers Trust, facilitated by Powys County Council in collaboration with Welsh Government to find nature based solutions to flood risks across the county.
