The Lewknor Brook runs from Lewknor and meets the Chalgrove Brook just outside of Cuxham. A small stream runs into the brook from Shiburn. The Lewknor Brook is mainly surrounded by grassland and pasture. There is one small sewage treatment works on the Lewknor Brook. As it is a small works, it does not have phosphorus removal on the effluent and results in high concentrations in the receiving water.
In 2015 the Environment Agency classified the Lewknor Brook as “moderate”, based on multiple factors. Water quality along the Lewknor Brook is surprisingly classified as “high” for all measurable factors (under Water Framework Directive), except for phosphate which is “moderate”; this is likely to be as a direct result of the sewage treatment works impact. The Lewknor Brook was targeted to reach “moderate” status by 2015 and future targets are being set now. A cost-benefit analysis means that it is currently considered not feasible to improve the phosphate issue. We hope that this may change in the future as investment is put into the sewage treatment works.
You can find out more about the classification of rivers in our catchment by using the Environment Agency’s Catchment Data Explorer.