On 1 July 2015, the European Court of Justice (ECJ) rendered its long-awaited judgment interpreting the EU Water Framework Directive 2000/60 (“WFD”). The ECJ ruled that the environmental objectives of the WFD are not merely objectives for management planning but also apply to individual projects. Member States may not authorise projects which may cause a deterioration of the status of a surface water body unless derogation is granted. Additionally the ECJ provided decisive criteria for determining whether there is a deterioration of the status of a body of water.


According to its first article, the WFD has two aims, to prevent deterioration of the status of all water bodies and to protect, enhance and restore those water bodies. Art. 4 of the WFD explains the obligation to prevent deterioration and introduces Annex V which establishes five status classifications (high, good, moderate, poor and bad) applicable to all types of water bodies. Accordingly, each quality element (related to the biological, hydromorphological and physico-chemical quality characteristics specific to each type of water body) as well as the ecological status of the water body as a whole will be classified based on the five status classi-fications. Under the rule of “one out all out” the ecological status of the body of water is determined based on its poorest quality element. The same is true for artificial and heavily modified water bodies, however, for these, it is not the ecological status that is decisive but rather the ecological potential.

Background of the Case

When deciding on the planning decision for deepening the Weser river in Northern Germany, authorities concluded that deterioration of surface water bodies, within the meaning of the WFD, was not expected because the project would not reduce the river’s overall ecological status (e.g. from moderate to poor). This line of reasoning is known as the “status class theory”. BUND, an environmental NGO, challenged the planning decision, arguing that any detrimental change to a body of water, even without a change of status class, constitutes a deterioration. This reasoning is known as the “status quo theory”. The German Federal Administrative Court (Bundesverwaltungsgericht) referred several questions on the meaning of the terms “environmental objectives” and “deterioration” to the ECJ for a preliminary ruling.

In his Opinion, Advocate General Jääskinen recommended a strict interpretation of the WFD. He took the position that the environmental objectives should not be qualified as mere management planning objectives with no link to or impact on individual projects but rather binding and applicable to the authorisation procedures for individual projects. Consequently, he held that in order to prevent deterioration, Member States must refuse authorisation of an individual project that may result in any deterioration – even if it does not result in a reduction of status classification. By interpreting the rule of no deterioration in this way, the Advocate General opted for the status quo theory. However, he acknowledged that derogations from the rule of no deterioration were allowed under the very precise provisions of the WFD.

The ECJ ruling

The ECJ, in accordance with the Advocate General, qualifies the planning objectives as specific instructions by which all projects must be judged, not as mere management-planning objectives. According to the Court, Member States must refuse authorisation for an individual project where it might cause a deterioration of the status of a body of surface water or where it jeopardises the attainment of good surface water status or of good ecological potential and good surface water chemical status.

The ECJ sees a deterioration of the status as soon as the status classification of at least one of the quality elements falls by one class, even if that fall does not result in a drop of the overall classification of the body of surface water. However, if the quality element concerned was already in the lowest class (and deterioration was not possible under the above-mentioned concept), any deterioration of that element would constitute a deterioration of the status. The ECJ explicitly rejects the idea of a de minimis threshold.

Most legal scholars agree that the environmental objectives of the WFD are not qualified as mere programmatic objectives must be seen as binding obligations to be observed in each and every authorisation procedure.

Observers of the proceedings expected the ECJ to follow the Advocate General’s strict inter-pretation of the rule of no deterioration but the Court decided differently. The ECJ’s ruling effectively introduced a modified status class theory, which on one hand is more stringent than the strict status class theory because it is not the overall status class of a body of water that is decisive but the classification of each single quality element. On the other hand, the ECJ’s ruling is less strict than Advocate General Jääskinen’s Opinion because it only sees a deterioration if the quality element decreases by a whole status class, whereas Advocate Gen-eral Jääskinen held all – even insignificant – impairments of a quality element amount to dete-rioration. The ECJ follows General Jääskinen’s strict interpretation only in cases where the relevant quality element is already in the poorest class – which, according to the ECJ is neces-sary to ensure that otherwise heavily damaged water bodies are not left unprotected.

Impacts of the judgement

Generally speaking, the ECJ ruling is a balanced decision, requiring Member States to take the environmental objectives seriously and making high demands on the rule of no deterioration. Yet it avoids that, for most cases, derogation will be necessary in cases of minor impairments. Although the WFD allows these derogations if strict requirements are met – there has to be good and thorough reasoning.

The ECJ’s decision will lead to problems for projects affecting waters that are in the poorest status class already because derogation will be required even if a project impairs this kind of water, even marginally.

Since the ruling only refers to the ecological status of water bodies it remains to be seen whether the ECJ’s interpretation will be applied to the objective of a good chemical status. Good chemical status is an objective for both surface water (in addition to the ecological status) as well as for groundwater (in addition to the quantitative status). Unlike ecological status, chemical status is divided into only two status classes “good” and “poor”. If one applied the ECJ´s approach to the chemical status any kind of impairment of a water body in “poor chemical status” would be regarded as deterioration. This is relevant especially for impairment due to wastewater discharge – because the WFD only provides for derogation for modifications to the physical characteristics of a surface water body but not for waste water discharges or other chemical impairments. One may question whether the strict interpretation of the rule of no deterioration combined with the absence of an appropriate derogation is in line with the principle of proportionality, which is binding for the interpretation of EU law through the Charta of Fundamental Rights of the European Union.

Clearly the last word on the rule of no deterioration has not yet been spoken.