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    -Yves Mérillon \ Loire-Brittany water agency
    "In the run-up to the updated status reports, the characterisation of pressures (abstractions, effluents, hydromorphological alterations) rounds out the evaluation of water status with an analysis of the causes of degradation..."

Characterising the pressures weighing on aquatic environments

To enable water stakeholders to update the status reports for the various river basins in 2013, Onema coordinated a vast, collective project to monitor pressures. The result is a methods guide to describe the pressures weighing on rivers that was drafted and distributed to the concerned water stakeholders.

The first status report on aquatic environments in 2003-2004, an unprecedented event imposed by the European water framework directive (WFD), encountered difficulties in describing the pressures weighing on rivers and groundwater.

To mitigate those difficulties, an ambitious project was launched in 2010 to develop new methods on the national level and to supply the necessary tools and data for the upcoming status reports. Managed by the Ecology ministry and coordinated technically by Onema, the project mobilised the Ecology, Agriculture/Fisheries and Health ministries, the six Water agencies, the basin organisations, research organisations (Ineris, BRGM, Irstea, INRA) and Onema.

Simple, operational methods

A dozen methods were devised or improved to describe four major types of pressure:

  • 1) nonpoint-source pollution (nitrogen, phosphorous, pesticides);
  • 2) water abstractions;
  • 3) industrial and urban pollution;
  • 4) hydromorphological alterations.

They are divided into groups according to the type of water body, i.e. surface waters (rivers, lakes, coastal waters) and groundwater.

It is now possible to predict nitrogen transfers from agricultural sources to aquatic environments and foresee the impact as a function of the concentration, and to assess the risks of contamination by phytosanitary products for all water bodies. Interactive maps graphically present the results.

Another example in the field of hydromorphology is the Syrah method that maps zones at risk of hydromorphological alteration that could result in failure to achieve good ecological status. The method analyses engineering work and water uses causing alterations in the seven river basins of continental France.

Some types of pressure, e.g. micropollutants (other than pesticides) do not yet have the necessary methods for entire water bodies. This will require a great deal of further research. In addition, a number of methods currently available will continue to be developed for the next WFD cycle.

The guide is supplied with a second guide drafted by the Ecology ministry on the statusreport update procedure.

Click here to consult the guide