It is an acronym already well known for its ability to debunk preconceived ideas about water sharing: HMUC, for hydrology, environments, uses and climate. Until now, this scientific study concerned a specific watershed. The conclusions are sometimes well accepted there, as in the Creuse basin where this study was validated. But there are sometimes tensions like in Touraine Vienne or intimidation like in the Clain basin (Vienne), where validation was postponed by the local water commission (CLE) pending a socio-economic component. economic.
“Water has become a subject of tension”
The Loire Bretagne water agency (AELB) has just announced the launch of its own HMUC study, on October 3, 2024, on the scale of its (huge) territory of competence (1). “Until now, we had imagined abundant water but with global warming, it has become a subject of tension, a major political subject”says Thierry Burlot, president of the Loire Bretagne basin committee.
“If we are not careful, we will have to manage crises constantly, the HMUC study should allow us to gain height”adds Loïc Obled, general director of the AELB.
Three years of study for one million euros
The HMUC study will last three years and cost one million euros. The hydrology part will be entrusted to Antea group. The National Institute for Agricultural Research (INRAE) will be responsible for the climate change component. The uses have been entrusted to Suez. The AELB has not yet found the actor in charge of the chapter on environments.
This “HMUC Loire” will draw on data collected as part of studies already carried out in the basins. Usually, an HMUC study serves as the basis for a territorial water management project (PTGE). This will not be the case here.
“Learn collectively to manage the resource well”
“What we are looking for is the coherence of the river. The question of the great water cycle raises the question of solidarity between upstream and downstream, between the city and the countrysidesays Thierry Burlot. If we want to make the right decisions tomorrow, we better understand things well. Having lived in Sainte-Soline, I am certain that appropriation of this subject in the territory is essential. We must learn collectively to manage the resource well. »
(1) The AELB Loire-Bretagne operates in 36 departments (concerned in whole or in part depending on their watersheds), through five delegations: Allier-Loire upstream, Center Loire, Poitou Limousin, Maine-Loire-Océan and Armorica.
What is the HMUC study?
The scientific study of hydrology, environments, uses and climate (HMUC) observes and quantifies surface and underground water resources. At the scale of a hydrological basin, it makes it possible to define the needs of natural environments for respect for biological life, the conservation and free flow of water, the needs for drinking water and human activities according to the meteorological developments and by integrating the consequences of climate change at work caused by the release of greenhouse gases linked to human activities.
