Client: Private Client, West Sussex
Project Title: Bank Erosion Repair
Scope of works: To repair existing, and prevent further, erosion of stream bank
The client’s property had a stream running through their garden which was suffering from bank erosion. In the centre of the stream they had created a lined pond. Our original brief was to tidy the pond and prevent further erosion on the bank of the stream.
The garden was situated on Weald clay and during 2020, the stream was the lowest they had ever seen it, although the water in the past has risen several feet.
The pond itself was created about 15 years ago and has an artificial liner and because their dog was continually emerging from the water covered in mud, the client felt that the pond needed dredging.
Upon site inspection, it was apparent that the pond did indeed require some marginal plant maintenance and existing reeds removing which would allow their dog to emerge mud free.
Gabion baskets were considered as a means to stop erosion but the warm look of English oak was preferred. They also already had some large blocks of local stone in their garden and wanted to incorporate these into any design we came up with.
Hiding the existing drainage pipes that entered the stream was also on their wish list.
Our solution was to install an oak revetment with pre-planted coir rolls in small groups. The oak was attached to a Nicospan system supported by timber posts along both sides of the 80m long stream.
The existing wooden bridge was removed while work took place and reinstated on completion.
The pond was cleared of reeds and given a routine maintenance and spruce up.
Before & After
To complete the project, we constructed a head wall with the client’s own rockery stones and created a stable and aesthetically pleasing feature.
The banks of the stream were very steep, and we needed to find a way to stop any slippage, though terracing was thought to be too formal.
The 45-degree slope was undercut as you can see in the photos below.
The oak revetment had to be shaped to form the required curve which was made even more complex due to the change in the horizontal level as well as the curves to follow both the slope and the curve.
Tree root balls also had to be removed from the slopes.
The ground conditions were the biggest challenge, but fortunately the weather was in our favour and slope stability was maintained.
Finally, the 80 square metre terrace was finished with topsoil and turfed.
Once on site, we were then asked to create two terraced steps to the north of the pond using matching materials to those we have used to create the oak revetments.
Project completed on time, within budget with one very happy client and a clean dog.