Live willow revetments are ideally suited to large river channels and can provide riverbank stability with high biodiversity value.
A live willow brush mattress is capable of withstanding very high flow velocities and is therefore suitable in higher energy, mobile gravel bed rivers. The branches absorb flow energy, trap sediment and seed and as a result evolve with high biodiversity value. River scale flume trials undertaken in Austria demonstrated that this revetment, with one season’s growth, could withstand velocities over 5 m/s.
Willow spiling is a traditional technique which should only be used in low energy situations, but is a good method of retaining vertically eroded riverbanks in areas where regrading the bank is not possible.