Nutrients, algal growth and sedimentation are the primary causes of biological failures in the Kennet catchment
Nutrients emanate mainly from diffuse agricultural sources and sewage works, although discharges from septic tanks and urban runoff also contribute. Algae develop in response to high nutrient levels and elevated temperatures.
Not yet fully understood
Sedimentation is largely from agricultural runoff and causes siltation of the river bed, with impacts on macrophyte growth and fish spawning. Impacts can be further aggravated by river dredging and over-wide and/or impounded river channels which cause sediment deposition and nutrient storage. The influence of point and diffuse sources, their spatial extent and ecological impact are not yet fully understood.