Nathalie BARDIN

Établissement Public Territorial du Bassin de la Dordogne

Water quality and eutrophisation

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

La Cère

La Vézère

L’isle

La Dordogne

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Dordogne and its principal tributaries

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Geological map of the Dordogne basin

Quaternar alluvial

Volcanic rock

Sand, clay and gravel

Karstic limestone

Crystalline rock

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Population density

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Industrial waste

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Agricultural aspects

IRRIGATION

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

61% water bodies (principal and very

small) in good condition by 2015

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Inventory Water Framework Directive

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Pressures stemming from agricultural pesticides

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Zones susceptible to eutrophication

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Risk of degeneration trough coliform bacteria

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

What strategies does EPIDOR apply to improve water quality ?

1. Collecting data: evaluations of water quality, audit on sanitation, study of aquatic leisure frequentation, studying eutrophication of the rivers, diagnostics watershed upstream of lakes, …

2. Setting priorities and programs of action with animation territorial (contracts river) or thematic

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

domestic sanitation

Results: : 44% of communes have a collective sanitation system (the same rate

French)

better account of bathing usage on the sections most frequented by effacing of wastes in summer (infiltration) or appropriate treatment (lagoon finishing, UV, ...) for all the recent STEP

Working with departments (counties) and the Water Agency to improve the equipment

Still to do :• Equip communes with fewer than 500 inhabitants

• Improve the functioning of collective sanitation system above all in rainy periods

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Limiting agricultural pollution Specific actions within the compass of the river contracts:

effluents from cheese production in the Upper Dordogne, studies currently in progress on the treatment of effluents from wine production in the Lower Dordogne, participation in the drafting of local plans

Results : Launching of a programme of works with financial incentives

(from the region, Europe, Water Agency) for the cheese producers

Still to do : To achieve a clear diagnosis and a strategy for action at the level

of the entire river basin

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Eutrophication and the cyanobacteria

Study of the eutrophication of the Borte les Orgues and Saint-Etienne-Cantalès reservoirs

Identification of bodies of water affected by cyanobacteria

Helping local bodies with diagnostic studies relating to the sources feeding their stretches of water bodies

Studying the development of cyanobacteria in the Bort les Orgues reservoir

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Eutrophication and the cyanobacteriaResults : Mapping of the waters affected

Diagnostic studies of the the main bodies of water impacted are now completed and the established facts are similar for each of them, as are the proposed programmes for action

The Bort study shows :

Little development attributable to the partial lowering of the dam in 2005

Decreasing gradient of eutrophication from upstream to downstream Different species upstream and downstream of the reservoir Influence of the winds on the structuration proposal The influence of thermic stratification for an alarm

system

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Nathalie BARDINWater quality and eutrophisation Établissement Public Territorial du Bassin de la Dordogne

Eutrophication and the cyanobacteria

Limitations :

No feedback of the experience gained from establishing the action programmes nor of their efficacity. Reasons :

• Studies effected too recently• Heavy financial costs• Difficult for local bodies to invest in actions taken for the

basin overall

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Water quality issues Continuation of sanitation equipment

Improving the reliability of existing installations and taking better account of bathing usage

Evaluation of the contamination by emergent polluants and toxic products

Reducing the diffuse pollution from agriculture

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation

Merci de votre attention

Nathalie BARDIN Établissement Public Territorial du Bassin de la DordogneWater quality and eutrophisation