Chalk stream flow deflector. Flow deflector constructed from bundles of hazelwood branches. The purpose of deflectors like this is to increase the rate of flow, therefore causing the faster water to scour the stream bed of silt. This is being done here to prevent silt building up under a low bridge downstream which has caused flooding. The deflectors also encourage increased stream diversity and the establishment of marginal wetland plants and habitats for a greater variety of aquatic life.