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  • VIEWPOINT OF A PARTNER

    -Renaud Jalinoux \ CISALB
    "CISALB has been confronted with water deficits since 2003. In 2010, the board launched two studies to determine the maximum abstractable volumes. These studies were among the first undertaken in the Rhône-Méditerranée region..."

Studies to precisely adjust abstraction volumes

Studies to estimate the abstractable volumes of water from rivers in the Rhône-Méditerranée basin were launched in 2010 to achieve better preservation and sharing of water resources in the future. These studies involved the Onema Rhône-Alpes Méditerranée and Bourgogne Franche-Comté regional offices and the concerned local offices.

Increasing demand for water to meet growing human needs and increasingly frequent dry periods have resulted in shortages over 40% of the Rhône-Méditerranée basin. In its RBMP (river-basin management plan) for 2010-2015, the Rhône-Méditerranée- Corse Water agency set as one of its major goals a better balance between supply and demand to be achieved through better sharing of the resource and better planning for the future. In compliance with recent regulations, notably the 2008 regulation, studies to estimate the overall abstractable volumes of water were launched in 2010 in the areas where deficits had been noted. Of the 70 studies to be finished by the end of 2014, just under half were completed in 2012. These studies, run by the local management structures or by the regional environmental agencies and the Water agencies in the sub-basins where deficits have been noted, supply the data required to adjust abstraction permits to the available resource.

A study followed by negotiations

These studies to estimate the overall abstractable volumes of water last two years on average and comprise several successive phases, including a description of the subbasin, a report on current abstractions and future needs, and a quantitative estimate of the available resources. The biological minimum discharges and targeted low-flow discharges, determined with technical support from Onema, are also taken into account when making recommendations on the overall abstractable volumes and the relative shares assigned to each usage. Following the studies and technical recommendations, a negotiation presided by the State and the local management boards, involving all stakeholders, is launched to draw up the water-management plan including a work programme and the necessary adjustments in abstractions to comply with the recommended abstractable volumes.

Onema plays a multi-facetted role

Onema intervenes on multiple levels to assist during the studies to estimate the overall abstractable volumes of water. On the local level, Onema personnel provide their knowledge on how rivers function, on anthropogenic pressures and on fish ecosystems. The Onema regional offices are on hand primarily for technical support on methods and for the strategic interpretation of the results. They also participate in the meetings to monitor study progress. Finally, the Onema/Irstea Ecohydraulic centre provides the regional offices with assistance on the methods employed for the habitat models.

Contact : marion.langon@onema.fr