In 2022, the Loire-Brittany Water Agency published a guide to help those involved in local water management carry out ‘Hydrology, Environments, Uses, Climate’ (HMUC) analyses. This guide has been updated and expanded, and a new version has been online since the end of 2024.
Hydrology, Environments, Uses, Climate’ (HMUC) analyses provide in-depth knowledge of available resources, existing pressures, their spatial and temporal distribution, as well as the needs of environments and their interactions.They are integrated into processes such as SAGEs and PTGEs. In particular, they serve as a tool for assessing the volumes that can be abstracted in the Loire-Brittany basin.
The first version of the HMUC guide was published in 2022. It has been updated to take account of feedback from the first studies launched in the Loire-Brittany basin, and the recommendations of the report by the General Inspectorate for the Environment and Sustainable Development (IGEDD) and the General Council for Food, Agriculture and Rural Areas (CGAAER) in July 2024 (https://www.gesteau.fr/actualite/rapport-de-ligedd-sur-les-analyses-hmuc-dans-le-bassin-loire-bretagne).The changes and additions made in this new version are the result of consultation with local stakeholders and discussions held by a working group comprising government departments from the Loire-Brittany basin (DREAL, DDT, DRAAF), regional delegations of the OFB and the Water Agency, SAGE coordinators and technical service providers. It was written jointly by the DREAL for the basin, the OFB and the Loire-Brittany Water Agency.
The guide is divided into four parts:
- Part 1 - Description of the context, objectives and main principles for carrying out an HMUC analysis
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Part 2 - Methodological framework for HMUC analysis: acquiring knowledge by theme
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Part 3 - Methodological framework for HMUC analysis: environmental diagnosis through global analysis
Part 4 - Methodological framework for the decision-making phase to define management values
=> Consult the guide ‘Analyses Hydrologie-Milieux-Usages-Climat (HMUC), guide et recommandations méthodologiques Bassin Loire-Bretagne’.
In addition to the guide, a summary brochure and two videos have been produced to explain the purpose and process of HMUC analyses to non-specialist local players:
=> Consult the communication brochure