Dry period water management plans on Adour-Garonne basin, an example of partnership between basin authorities and the agriculture world

The Adour-Garonne basin (south-west of France), structured around the rivers Adour and Garonne, does not really present a water deficit as the common understanding used to qualify the Mediterranean countries. The rivers in the basin have a permanent regime and annual uses correspond only to 3 billions m(3), among 80 billions m(3) theoretically available. Nevertheless, its meridional position makes necessary irrigation during the summer-season when, nival reserves are exhausted and rain is quite rare, This irrigation is practice on 600 000 hectares with a high percentage of corn farming, whose activity is used otherwise as a base rate for compensatory mechanism of the European Common Policy for Agriculture. Since the water management is not a tool for economic activity regulation, the government and the basin authorities, through their strategic documents like the water law of 1992, had worked toward a better valorisation of available tools such as - Regulation tool: authorisation. - Fiscal tool: license fee or tax. - Financial tool: water price and subsidies. This research to restore the water balance is now made by bringing into line of "dry period water management plans" (Plans de Gestion d'Etiages - P.G.E.). These P.G.E. are leaning against an water flow target for dry periods (Debits Objectifis d'Etiages - D.O.E.), that is a concept established in all nodal points in the water basin. This management optimisation of the quantitative water resources is very often conducted by contractual channels with farmers, that are represented by their professional organisms. One can note that this procedure, whose results are perceptible, is progressively used in other fields a agriculture activity. This policy is not without effects upon water quality (fertilizing and pesticides control, farming effluent valorisation, diffuse pollution control) and involve every day more farmers towards a responsible management of water and environmental.