I found this video yesterday about natural flood management in the catchment around Stroud in Gloucestershire. It is a detailed video which shows specific measures that have been taken to slow the flow by a range of individuals and organisations. It is well worth a watch.
Another blog ‘Tree planting and reducing flooding – will it work?‘ was also brought to my attention by a reader of my blog. It is by Miles Marshall of the Centre for Ecology and Hydrology. He was the lead researcher who carried out the work at Pontbren in mid Wales. In the study trees were planted on previously grazed pasture and they measured the subsequent effects on soil hydraulic properties and runoff processes. They found that soil infiltration rates were 67x times faster and surface runoff volumes were reduced by 78% under trees compared with grassland.
Marshall rightly cautions the reader saying that more research is required to determine which species of tree work best, what age of tree is best, can the ideas be scaled up to make a real difference etc.
He also says that tree planting to reduce flooding is only one of the options that needs to be considered. He argues that catchment wide initiatives such as the one described above for the Stroud Valleys are needed as well. As I have argued many times before land use is also a key issue e.g. maize on steep slopes near to streams and roads.