In the 1990s, water policy in the European Union was fragmented with respect to objectives and means. The member states agreed on the need for a single piece of framework legislation to resolve these problems and agreed on the following aims (1):

• expanding the scope of water protection to all waters, surface waters and groundwater
• achieving "good status" for all waters by a set deadline
• water management based on river basins
• "combined approach" of emission limit values and quality standards
• getting the prices right
• getting citizens involved more closely
• streamlining legislation

As consequence, the "Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy", in short, the EU Water Framework Directive (WFD) was adopted in 2000.

WFD objectives are the general protection of the aquatic ecology, the specific protection of unique and valuable habitats, the protection of drinking water resources, and the protection of bathing water. All these objectives must be integrated for each river basin, including transitional and coastal water.

The WFD goal is to ensure a ‘good status’ in Europe’s rivers, lakes, groundwater bodies and coastal waters. The ecological status of surface waters is defined by the following quality elements:

• Biological quality elements (fish, benthic, invertebrates, aquatic flora)

The following elements only support the biological elements:

• Hydromorphological quality elements (e.g. river bed structure or substrate)
• Physicochemical quality elements (thermal, oxygenation and nutrient conditions)
• Chemical quality elements (environmental quality standards for pollutants)

The WFD classification scheme for surface water ecological status includes five categories: high, good, moderate, poor and bad. ‘High status’ means no or very low human pressure. ‘Good status’ means a ‘slight’ deviation from this condition (2).

A common implementation strategy has been developed to ensure a joint WFD implementation. A separate guidance document provides definitions and explains the implementation process for the surface water categories ‘Transitional and Coastal Waters’ (3):

“Transitional waters are bodies of surface water in the vicinity of river mouths which are partly saline in character as a result of their proximity to coastal waters but which are substantially influenced by freshwater flows.”

“Coastal water means surface water on the landward side of a line, every point of which is at a distance of one nautical mile on the seaward side from the nearest point of the baseline from which the breadth of territorial waters is measured, extending where appropriate up to the outer limit of transitional waters.”

Surface water bodies sub-divide transitional and coastal waters. They are the smallest management unit of the WFD.

Surface water types: “For each surface water category, the relevant surface water bodies within the river basin district shall be differentiated according to type.” These types are defined by factors such as latitude, longitude, tidal range, salinity or optional factors like depth, current velocity, water residence time, mean water temperature or turbidity (System B).

Reference conditions are a description of the biological quality elements at high status.

The implementation timetable include the following major actions:

• To identify the individual river basins lying within their national territory and assign them to River Basin Districts (RBDs) and identify competent authorities
• To characterise river basin districts in terms of pressures, impacts and economics of water uses, including a register of protected areas lying within the river basin district
• To carry out, jointly and together with the European Commission, the intercalibration of the ecological status classification systems
• To make operational the monitoring networks
• Based on sound monitoring and the analysis of the characteristics of the river basin, to identify a programme of measures for achieving cost-effectively the environmental objectives of the WFD
• To produce and publish River Basin Management Plans (RBMPs) for each RBD including the designation of heavily modified water bodies
• To implement water pricing policies that enhance the sustainability of water resources
• To make the measures of the programme operational
• To implement the programmes of measures and achieve the environmental objectives by 2015

The implementation timetable was much too ambitious and the implementation process is still ongoing.