EU law theoretically does not preclude the diversion of a river, but the member state must precisely identify the adverse impact of the project on sites concerned and take all compensatory measures needed to protect the environment. This was the answer given by the EU Court of Justice, on 11 September (Case C-43/10), to several questions submitted to it by the Greek Council of State.
From Ancient Greece
I’m sure the reader remembers the ancient Greek story of how Thales of Miletus diverted the river Halys so Croesus’ army could cross– a highly doubtful story since already Herodotus thought bridges were used. But anyway, one thing is certain: Thales did not have to take in account very European directives which now impose very strict conditions for executing such a huge infrastructure work.
Via EU law
Whoever decides to undertake the diversion of a waterway must abide by the provisions of the following directives: the Water Framework Directive (2000/60/EC) and Directive 85/337/EEC on the assessment of the effects of certain public and private projects on the environment do not in principle preclude the project at issue, and last but not least the Habitats Directive (92/43/EEC).
…to modern Greece
Greece has worked for years to partially divert the River Acheloos (Western Greece) into the River Pineios (Eastern Greece) and to use its upper waters to construct dams. The aim is to meet the irrigation needs of Thessaly, to produce electricity and to supply water to a number of towns and cities in the region. However, a number of local authorities and certain associations applied to the Council of State for annulment of the project.
Public interest vs ecological impact
After having observed that the Water Framework Directive (2000/60/EC) and Directive 85/337/EEC on the assessment of the effects of certain public and private projects on the environment do not in principle preclude the project at issue, the Court examined the conditions laid down in the Habitats Directive (92/43/EEC). The Court stressed that a project for the diversion of water, which is not necessary to the conservation of a special protection area (SPA) but likely to have a significant effect on it, cannot be authorised in the absence of reliable data concerning birds in the area.
However, if a project must be carried out for imperative reasons of overriding public interest, including those of a social or economic nature, in spite of a negative assessment of the effects on the site and if there are no alternative solutions, knowledge of the impacts is an essential prerequisite for weighing the public interest reasons and damage to the site.
The court ruled that irrigation and the supply of drinking water constitute an overriding public interest that can justify a water diversion project in the absence of alternative solutions. However, the only considerations that may be raised are those relating to human health or beneficial consequences of primary importance for the environment. According to the Court the supply of drinking water is included in considerations related to human health. As regards irrigation, it cannot be ruled out that, in some circumstances, it may have beneficial consequences for the environment. The Court also held that maintaining a biodiversity may in some cases require the encouragement of human activities such as the conversion of a natural fluvial ecosystem into a largely man-made fluvial and lacustrine ecosystem.
Court of Justice:
The full text of the judgment is published on the CURIA website on the day of delivery.
Pictures of the delivery of the judgment are available from “Europe by Satellite”
Information on the Habitats Directive on DG ENVI (European commission).