The Key Challenge Water Occitanie, five collaborative projects and six living labs for the assessment of the relevance of local water reuse solutions and their consequences

With nearly 6 million inhabitants, the Occitanie region is particularly affected at the hydro climatic level, mainly on the Pyrenean massif and the Mediterranean coast. Recent years have been marked by a succession of droughts and floods that have affected the territory and these climatic extremes are likely to increase, jeopardizing the security of the water supply for all uses and infrastructure, and the natural environments and ecosystem services they provide.Local water management solutions seem to be adapted to meet the challenges of climate change and its local consequences. In this context, the reuse of water already mobilized for other uses before partial return to the natural environment can be relevant alternatives to guarantee access to water, for various uses such as, for example, agricultural irrigation, urban cooling, irrigation of green spaces and golf courses, groundwater recharge... Among these solutions, the reuse of treated wastewater is encouraged by some stakeholders in the sector and users and seems to respond to several challenges. In France, less than 1% of wastewater is recycled, while reuse is widely adopted in some countries, such as Israel (90%), Spain (14%) or even Italy (8%). It is also presented as a possible option in the case of Southern countries.