Objective
The purpose of the ‘soft bank’ design is to maximise net biodiversity gain from the canal restoration. The objective of this ‘proof of concept’ is to assess the materials used and the practicalities of building the design.
The design achieves a covering of soil both below and above the water line. This is up to ½ metre deep over the liner system providing a favourable habitat for a wide variety of water margin plants, insects, invertebrates, amphibians and possibly also water voles.
Design
Two courses of hollow, interlocking blocks are used to provide a ‘retaining wall’ for the required depth of soil. The interlocking allows a stable wall to be built without the use of mortar. The hollow cells of the blocks are filled with soil as is the area behind the retaining wall. This provides a suitable environment for deep rooted water margin plants which in turn add further strength and stability to the wall. The top course of blocks is below water level.
The proof of concept is located on the off side bank to provide wildlife greater seclusion from towpath users and with the expectation that tall, luxuriant vegetation will develop, which is less desirable on the towpath bank.
Construction
The step-by-step sequence is shown here.
