Water Framework Directive catchment planning: a case study apportioning loads and assessing environmental benefits of programme of measures

摘要

Complying with proposed Water Framework Directive (WFD) water quality standards for ‘goodnecological status’ in England and Wales potentially requires a range of Programmes of Measuresn(PoMs) to control point and diffuse sources of pollution. There is an urgent need to define thenbenefits and costs of a range of potential PoMs. Water quality modelling can be used tonunderstand where the greatest impact in a catchment can be achieved through ‘end of pipe’ andndiffuse source reductions. This information can be used to guide cost-effective investment bynprivate water companies and those with responsibilities for agricultural, industrial and urbanndiffuse inputs. In the UK, river water quality modelling with the Environment Agency SIMCATnmodel is regarded as the best current approach to support decision making for river water qualitynmanagement and planning. The paper describes how a SIMCAT model has been used to conductna trial WFD integrated catchment planning study for the River Ribble catchment in the North Westnof England. The model has been used to assess over 80 catchment planning scenarios. Thenresults are being used support a national assessment of the cost-effectiveness of proposed PoMs.