Management Strategies and Mitigation Measures Required to Deliver the Water Framework Directive for Impoundments
WFD29/Vol.1 - Preliminary Guidance Document
WFD29/Vol.2 - Appendices

December 2004


Background to research
The implementation of the EC Water Framework Directive (WFD) requires the development of new approaches and methodologies by the competent authorities in the United Kingdom. One of these requirements involves developing procedures to ensure the adequate mitigation of the negative impacts created by the construction and operation of impoundments. Any activity to mitigate the environmental impact of an impoundment must reconcile the protection of the local aquatic ecology with the socio economic benefits of impoundments and must fit within the overall river basin management planning process.

Objectives of research
The Objective of the is to provide a Guidance Document which presents a user friendly guide for identifying best practice and cost-effective management strategies and mitigation measures for potential application to impoundments for hydro-power, flow regulation and water supply in order to meet the requirements of the Water Framework Directive in the UK.

Key findings and recommendations
The initial international review of impoundment management practices provided a legislative, planning, management and regulatory context for impoundments across five countries (Norway, France, Germany, Australia and USA) and identified typical and good practice mitigation measures. The review found that the licensing procedures in all countries were broadly similar. A two tiered approach to licensing, Environmental Impact Assessments for large impoundments and consultation with statutory and non-statutory bodies were evident in all countries and the majority of the countries applied the concept of time-limited licensing and the incorporation of conditions in the license to mitigate impacts on the surrounding environment.

A preliminary analysis of the mitigation techniques tried and tested by the five different countries showed that a substantial number are commonly used by all (e.g. compensation flows, fish passes, fish screens and measures to improve dissolved oxygen levels and maintain natural temperatures). Novel approaches were also identified (e.g. salt interception systems close to the coast in Australia, fish friendly turbines to prevent fish damage in USA, fish passes specifically for eels and a retaining weir dam to maintain water levels in an isolated area of the impounded water (Norway)).

The key elements of the Guidance Document are:

Additional discussion is also provided on:

The Guidance Document has been prepared in the light of:

The Guidance Document has been amended in light of recommendations made following trials by SEPA / EA licensing officers and private sector impoundment managers on the River Dee (Wales) and the Glendevon (Scotland).

The principal users of this guidance are envisaged to be the regulatory authorities (particularly SEPA and EA water resources licensing officers) and impoundment managers (private and public sector). The preliminary and final document can be used when:

It is intended that the methodology suggested in this preliminary guidance document will enrich the discussion of alternatives in public decision-making. It is important to note that the document contains the best recommendations of the consultants and does not necessarily represent the official views of SEPA and the EA.

Key Words
Water Framework Directive; impoundments; mitigation measures; cost effectiveness.

Copies of these reports are available from the Foundation:
Volume 1: Preliminary Guidance Document in electronic format on CDRom at 20.00 + VAT or hard copy at 35.00, less 20% to FWR members.
Volume 2: Appendices in electronic format at CDRom at 20.00 + VAT or hard copy at 50.00 less 20% to FWR members.

N.B. The reports are available for download from the SNIFFER Website