Water Framework Directive

The Water Framework Directive (WFD) is the most substantial piece of EC water legislation to date and is designed to improve and integrate the way water bodies are managed throughout Europe. In the UK, much of the implementation work will be undertaken by competent authorities. It came into force on 22 December 2000, and was put into UK law (transposed) in 2003. Member States must aim to reach good chemical and ecological status in inland and coastal waters by 2015.

It is designed to:

  • enhance the status and prevent further deterioration of aquatic ecosystems and associated wetlands, which depend on the aquatic ecosystems
  • promote the sustainable use of water
  • reduce pollution of water, especially by ‘priority’ and ‘priority hazardous’ substances (see Daughter Directives)
  • ensure progressive reduction of groundwater pollution

The United Kingdom Technical Advisory Group (UKTAG) was established to provide coordinated advice on technical aspects of the implementation of the Water Framework Directive (WFD) in the UK.  Part of the role of the UKTAG is to help assess the risk of water bodies failing to achieve the WFD's environmental objectives.  The UKTAG consider that non-native species are one of the significant pressures that could result in a water body failing to meet environmental objectives (such as failing to achieve good ecological status).

The UK TAG Alien Species Group (ASG) is a technical sub-group that provides scientific advice to the Water Framework Directive UK Technical Advisory Group.  The ASG uses scientific evidence to decide how an invasive non-native species should be categorised in relation to the potential level of adverse impact and risk it poses to the water environment; economic considerations or other issues are not taken into account at this stage.  Species are assessed to be of high, low, or unknown impact and this listing is then incorporated into guidance for the implementation of the Water Framework Directive (WFD).

Documents provided by the ASG are available here:


Other useful WFD links:


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