River Tame – Reddish Vale Country Park, Stockport

Project Brief

A large gravel bar had accumulated within the bed of the River Tame adjacent to the Reddish Vale Country Park. Unfortunately, this caused the flow of the river to be pushed over to one side of the channel; undercutting and eroding the banks and threatening a popular footpath through the park.

We were contacted by the client to advise on the design and reinstatement of the river bank in three key locations and to provide a solution to prevent future natural channel adjustment destabilising the banks in this area.

Work / Solution

Before

Severe erosion of the right-hand bank of the River Tame in Reddish Vale resulting from natural channel adjustment upstream. 15m length of cliff erosion, though the total length of works required was nearly 40m.

During

The original design obtained by the client was for a rip-rap bank protection using rock rolls & geotextile matting and, if this had been constructed, would have created a very hard engineered bank edge, with limited habitat potential.

After reviewing the design, we suggested an alternative utilising willow spilling with a geotextile and gravel-retained ‘coirnet’ on the landward side. The design also incorporated live willow woody material to help deflect flow away from the bank, and in doing so provided a more sustainable, long-term solution and one that works with natural processes.

The client was more than happy to go with this alternative design as it was cheaper, more sustainable and created a more natural looking erosion-resistant bank.

Willow spilling revetment installed to form a new bank line

Gravel backfilled behind the willow spilling

Backfilled revetment

The existing bank is then regraded behind the new revetment

Regraded bank is covered with a biodegradable geotextile

A thin layer of soil was then placed over the geotextile

Woody debris (live willow) installed at the upstream end of the revetment

After

The completed works successfully reinstated the eroded bank margin along the River Tame. The final photo shows the site six months after completion with established vegetation growth, which is helping to protect the banks and to prevent against any future natural channel adjustment from destabilising the area.

Immediately after completion

6 months after completion