River bank revetment with willow spiling
Willow spiling is the most common and best known green solution for bank revetment. The technique uses woven living willow to form flexible, live, growing structures which resist and deflect water flows, enabling the bank and vegetation to naturally re-generate and stabilise to prevent further erosion.
Willow spiling is a traditional soft engineering technique used to stabilise eroding banks. It consists of weaving live willow rods between live willow stakes set into the affected bank at regular intervals. The space behind the willow wall to the existing bank is then filled with soil to provide an area for the willow roots to grow.
Osier willow is considered to be the most appropriate species to provide poles, due to its pliable nature and the fact that it is an indigenous species. Alternatively, commercially available alternatives could be used, but these will require more vertical support posts. Willow spiling is normally carried out between November and April during the harvesting of the willow (dependent upon the season) and should be installed within three weeks of harvest.