Leaky dams aim to reduce flooding risks

Forestry and Land Scotland (FLS) has installed over 150 leaky dams on its land along the River Peffery to help alleviate flooding and support local communities from the impact that floods often bring.

The dams – also known as large woody debris dams or leaky barriers – are part of the work FLS has undertaken to support the Peffery Restoration Project. The highly collaborative project is funded by the Scottish Government’s Nature Restoration Fund. It aims to reduce local flood risks and improve biodiversity in the River Peffery Catchment.

The work on building the dams was led by local firm Lockett Agri-Environmental who also manage the Peffery Restoration Project. As well as the leaky dam work, they also oversaw the installation of a flood control valve in Blackmuir Pond - found in FLS’ Blackmuir Woods - that will regulate the water level in response to any local flood events.

Additionally, FLS staff have been riparian planting on FLS land in the upper tributaries of the River Peffery. Planting trees along the river bank can reduce flooding downstream by slowing the flow rate while also helping to improve water quality and act as a source of nutrients to enhance biodiversity.

FLS North Region Environment Advisor Colin Leslie said:

“For many people, the vison of a leaky dam probably goes against the notion of a way to reduce flooding. But they work by diverting water onto the floodplain, slowing the flow and reducing the flood peak - especially during high flows. Leaky dams replicate the natural obstruction in rivers caused by falling trees and branches.

“At Blackmuir Pond we have removed vegetation to increase capacity and improve conditions for great-crested newts and the flood control valve gives us more control to regulate the water level in the pond during flooding events.

“The work FLS is doing is all linked with wider efforts of ecological restoration and natural flood management techniques going on across the catchment area as part of the River Peffery Restoration Project and is aimed at reducing flooding in Strathpeffer and Dingwall.”

Individually, each of these nature-based flood mitigation measures may not seem like much. However, they all form part of the jigsaw puzzle that when put together can improve and restore biodiversity levels in the catchment area and decrease flood damage to land and homes.

Hannah Humphreys of Lockett Agri-Environmental said:

“Working at a catchment scale is essential if we want to reduce flood risk and improve biodiversity. The work on FLS land is a really important part of the work in the wider Peffery catchment. Slowing the flow of water in the headwaters of the catchment is good, cost-effective way of helping reduce flood risk.

"The work at the Blackmuir site is especially exciting. Not only have we put in measures that reduce the risk of water running down the streets of Strathpeffer, we’ve also managed to enhance habitats for great crested newts which are a local conservation priority.”

Additional: 

The River Peffery Restoration Project is a highly collaborative project that brings together a wide range of people and organisations to work towards the restoration of the entire River Peffery catchment.

Notes to editors

1. Forestry and Land Scotland (FLS) manages forests and land owned by Scottish Ministers in a way that supports and enables economically sustainable forestry; conserves and enhances the environment; delivers benefits for people and nature; and supports Scottish Ministers in their stewardship of Scotland's national forests and land.
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3. Media enquiries to Neil Ratley, Media Manager, Forestry and Land Scotland Media Office 07748 872785 or neil.ratley@forestryandland.gov.scot