In year 2000, the EC Member States agreed on a joint framework, “Community action in the field of water policy” (2000/60/EG), commonly referred to as the EC Water Framework Directive (WFD). In Sweden, the Directive is enforced primarily through Ordinance SFS 2004:660, while the specific assessment criteria used to assess water status are outlined in Regulation NFS 2008:1.
The WFD requires that all EC Member States carry out regular, coordinated assessments of water status and develop programmes of measures for groundwater, inland surface waters, transitional waters, and coastal waters extending one nautical mile from the baseline from which the territorial waters are measured. The aim of the Directive is to achieve and maintain “good water status” in all Member States. Water status should be assessed and reported to the EC every six years. The Directive establishes guidelines for the environmental elements that should form the basis for the assessment, while leaving room for detailed interpretation by the Member States. The following terms are central to WFD implementation:
Quality elements
For the assessment of water status, the WFD establishes guidelines as to what quality elements should be considered. In Sweden, the term “quality elements” is translated as kvalitetsfaktorer. The ecological status of waters is determined based on a set of biological quality elements (BQEs). The BQEs differ somewhat between coastal and inland waters, but mainly relate to macrophytes, benthic invertebrates, and phytoplankton. In inland waters, the assessment is also based on fish and benthic diatoms. These biological quality elements are the focus of WATERS research.
To meet WFD demands, EC Member States must determine what indicators should be used for assessing the status of each quality element. In Sweden and many other countries, for example, the maximum depth distribution is used as an indicator in assessing macrophyte status in coastal waters.
Reference conditions and class boundaries
Another central requirement of the WFD is to define what constitutes “good status” for each indicator used in the assessment. This is usually done, first, by defining a type-specific reference condition, i.e., a condition that reflects minor or no impact from human pressures. The reference condition is defined as representative of “high” quality for the particular water type and is used as a starting point for defining five descending water quality classes: “high”, “good”, “moderate”, “poor”, and “bad”. The Directive aims to achieve good water status, so it allows slight deviation from the type-specific reference condition. However, areas where the current water status is high must not deteriorate.
Integrated assessment of water quality
To assess the ecological status of a particular water body, all biological quality elements should be considered when providing the overall water status classification. Integrated assessment is crucial, since there are legally binding requirements to improve the status of waters that do not reach “good status”.
Assessment criteria
In Sweden, the principles used to classify water status, for example, instructions on what parameters to measure and how to measure them, class boundaries for the resulting indicators, and instructions on how to conduct the integrated assessment, are labelled bedömningsgrunder, loosely translatable as “assessment criteria”. The detailed instructions are available only in Swedish.
