A river catchment modelling approach to urban wet weather discharge control strategies for the Water Framework Directive (original) (raw)

The UK is now nearing the end of a £6 billion investment programme to comply with the Urban Wastewater Treatment Directive. This will see the end of its CSO problem in terms of both visual and acute water quality problems associated with the immediate impact of urban wet weather discharges. However, the Water Framework Directive will drive improvements in water bodies over the next 20 years. The development of catchment plans requires, amongst others, an assessment of the potential risk of impact from urban wet weather discharges as a source of diffuse pollution. A catchment study has used a water quality modelling approach to assess the apportionment of pollution sources across the catchment and the potential benefits of a range of control measures. The results indicated that urban wet weather discharges can be significant at a local level. This emphasises the need for targeted measures rather than ‘ad hoc’ global measures across a catchment.