Cutting-edge project to reduce flooding of River Pang

A partnership between the Pang Valley Flood Forum, University of Reading researchers, the Environment Agency and the Englefield Estate is using state-of-the-art technology to survey the River Pang, with the aim of reducing flooding.

Sixty-four leaky wooden structures – 'leaky dams' – have been installed up and down the Pang over the past three years.

The structures are entirely natural, using recycled debris from the river and surrounding forest.

Englefield Estate forestry manager Richard Edwards is leading a team undertaking the project on the ground.

Mr Edwards said: "Leaky dams are structures that allow the passage of some water through them, whilst holding some water back.

"They emulate nature, such as fallen trees or other debris in the river, and slow the river down without using hard engineering.

"We've used trees that have been found close by and it’s done using all-natural materials."

As flooding is often the result of broader factors than heavier-than-average rainfall, an innovative technological approach is required to control the Pang.

Flow monitoring equipment, including time-lapse cameras, is being used to monitor the effectiveness of the dams.

The project was made possible by a grant from the Department for Environment, Food and Rural Affairs (Defra).

Pang Valley Flood Forum chairwoman Kay Lacey said: "The 2007 floods were horrendous for Pangbourne, with over 120 homes affected and people out of their homes for six to nine months.

"A study after the flooding showed that there were no big, hard engineering solutions that would work for Pangbourne, so we looked for alternatives.

"We heard about the use of natural flood management in other areas and were fortunate to secure a Defra grant to run a pilot project of 'leaky dams' on the River Pang's tributaries with the aim of seeing whether they would reduce flood risk further downstream."

A Reading PhD student attached to the project, Gabrielle Powell, said: "The area around the River Pang and its tributaries is made up of chalk with clay overlays.

"Chalk is very good at absorbing rainfall, whereas the clay just lets the rain roll over the top, which can cause flash flooding.

"This pilot project is looking at the efficiency of leaky dams, to see whether they can slow the flow and prevent big flood events.

"This is being measured with time-lapse cameras to give us a visual update and level sensors to give us numerical data to evaluate.

"Preliminary analysis has shown a slowing of the peak of the flow, but with so many variables, such as the size of rain events, saturation levels and flow profiles, we need to gather more data to understand the impact fully.

"This is early days for the project, but the initial signs are positive."