Leaky dams

"Leaky dams" helping reduce flood risk in Harrop Brook and River Dean

image

"Leaky dams" at Pott Shrigley in Cheshire have been working well during Storm Barra over the past couple of days, helping to slow down the flow of flood water in Harrop Brook and the River Dean. 

Leaky by name, leaky by nature, even during high flows, "leaky dams" are built in small streams from natural materials - they will only let a certain amount of water through, slowly draining the trapped water to reduce the flood peak.  They are part of Natural Flood Management measures being implemented by a range of public sector and third sector organisations across the Mersey catchment to help reduce flood risk.

Funded by the Environment Agency, Mersey Rivers Trust installed the leaky dams at Pott Shrigley in March 2021, working in partnership with local farmers and landowners. Monitoring by Mersey Rivers Trust staff today (9 December) has shown that these new leaky dams have been able to hold back water in the headwaters of Harrop Brook and slowing down the flow of water into the downstream River Dean. 

Over the coming months, Mersey Rivers Trust will also be planting new trees at Pott Shrigley to complement the leaky dams.  Once established, the new trees will help take up water and allow more water to soak into the ground during flood conditions, further slowing the flow of water into the downstream river system.

News & Events

Wilmslow Bioblitz
08/08/26
Join us for a family-friendly Bioblitz on Saturday 8 August 2026
Kirkby Bioblitz
23/07/26
Join us for a family-friendly Bioblitz on Thursday 23rd July 2026
Croxteth Bioblitz July 2026
04/07/26
Join us at Croxteth Park on Saturday 4th July as part of Mersey Rivers Week
Balsam Bash at John O Jerusalem
01/07/26
Wednesday 1 July 2026 - Balsam Bash at John O Jerusalem
Balsam Bash at Rossmill
18/06/26
Thursday 18 June 2026 Balsam Bash at Rossmill
Mersey Valley Way Guided Walks
12/06/26
Summer guided walks on the River Mersey
Bracken Control: Tegg's Nose Country Park June
03/06/26
Wednesday 3 June. We're joining the Bollin Valley Partnership again to help control bracken and preserve valuable habitat at Tegg's Nose Country Park, Cheshire.
Mersey Rivers Week 2026
02/06/26
Join the Mersey Rivers Trust team at Mersey Rivers Week events in June and July 2026
Mersey Valley Way Official Opening
21/05/26
Baroness Hayman, Access Minister officially opens the Mersey Valley Way, England's first national river walk
Bracken Control at Tegg's Nose Country Park
20/05/26
Wednesday 20 May. We're joining the Bollin Valley Partnership to help control bracken and preserve valuable habitat at Tegg's Nose Country Park, Cheshire.
Big Give Earth Raise 2026
22/04/26
It's the Big Give Green Earth Raise Week 2026: all donations doubled! Please help us if you can...
Big River Watch April 2026
21/04/26
Big River Watch 24th - 30th April 2026
River Mersey Guided Walk & Litter Pick: Mersey Valley Way in Stockport
29/03/26
Sunday 29 March
Mersey Valley Way March Newsletter
25/03/26
Mersey Rivers Trust is delighted that the River Mersey in Greater Manchester has been selected for the first national river walk. Read about the progress in delivering the "Mersey Valley Way" in our March 2026 Newsletter.
Coppicing and dead hedging at Newgate Nature Reserve, Wilmslow
03/03/26
Tuesday 3 March. We're joining the Bollin Valley Partnership to undertake coppicing and dead hedging work at Newgate Nature Reserve, Wilmslow.
Battling the Birch at Lindow Common, Wilmslow
25/02/26
Wednesday 25 February. We're joining the Bollin Valley Partnership to help conserve the special habitat within Lindow Common in Wilmslow by removing self-seeded Birch.
View All