Lez Mediterranean basin



Flood is the first risk in France where it represents almost 60 % of the total natural disasters insured damages. Drought risk for farming is supposed to tremendously increase in the future causing economic and financial problems to an industry that is already suffering. Extreme drought are supposed not only to affect the yearly crops with important yield and revenue losses but also to affect perennial crops and farm financial health for several years, potentially jeopardizing the survival of farms and implying resilience mechanisms.


Nature Based Solutions

  • The idea is to explore whether karst water resources management is a potential NBS to reduce flood risks: while pumping in karst aquifers during dry periods, water is available for several usages (irrigation, drinking water supply, river minimum discharge); once the aquifer is depleted, it can store more water during floods. Co-benefits will result from surface water-related ecosystems in a better state (no hydrological drought).
  • Other classical Nature Based Solutions like natural retention basins, sludge, green roofs as well as alternative farming practices will also be investigated
  • If possible change the description of BRGM (3rd para.) with:
  • Researchers contributing to NAIAD belong to both the Water, Environment and Eco-technologies Division and the local action division. They are specialized in agricultural and environmental economics, hydrogeology of karst aquifers, natural hazard and risk assessment. They have extensive experience in hydro-economic modelling, environmental economics valuation methods, and participatory foresight approaches applied to groundwater management, planning and policy in European and non-European countries. They conduct and take part in numerous research projects on water management with a particular effort to combine both modelling and participative approaches on regional case studies. They also contribute to the assessment of groundwater contribution to flash floods and active management of karst aquifers. At a regional scale, researchers and engineers of BRGM’s local agencies, close to stakeholders, bring support for the realization of programs and dissemination of results.

Main Outcomes Sought

  • Demonstration of the interest of NBS / karst aquifer active management
  • Demonstration of the insurance value of NBS under study
  •  Set up of feasible technical and institutional NBS strategies
  • Acceptability of solutions

Key Stakeholders

Farmers, CCR (French reinsurer), insurances, water agency, local communities, environmental associations, government (local and national)…. Lez case study: Montpellier city, Syndicat du Bassin du Lez (SYBLE), Flood warning service (SPC)