[DREAL OCCITANIA] ROE — Referral Obstacle to Swivel

In metropolitan France, several tens of thousands of obstacles to flow — dams, locks, thresholds, mills — have been identified on rivers. They cause profound changes in the morphology and hydrology of aquatic environments, and significantly disrupt the functioning of these ecosystems. These changes affect the diversity and quality of aquatic habitats on which the survival of many animal and plant species depends. Very frequently, barriers to flow promote eutrophication, warm-up and evaporation processes. In addition, they fragment watercourses, hindering millenary movements of migratory species, limiting access to available habitats, genetically insulating populations and disrupting natural sedimentary processes. The scientific community considers that ecological fragmentation is one of the main causes of biodiversity erosion. Identify barriers and assess their impacts In order to meet the environmental and regulatory objectives (European Framework Directive and Good Water Status in 2015, Circular of 25 January 2010 on the implementation of the ecological continuity restoration plan, eel management plan), it is necessary to identify all obstacles in the territory, to have reliable, consolidated and homogeneous data at national level, as well as to assess the risks of impact on aquatic ecosystems (including on the ecological status of watercourses within the meaning of the WFD). This dual need will help in the implementation of public policies and prioritise interventions. What is the benchmark for barriers to flow? Until then, the data on the works were collected by the various water partners — the Ministry of Ecology, the Water Agencies, the deconcentrated services of the State, the territorial public basin establishments, research organisations, Waterways of France or EDF. They were then banned in their own databases, about thirty, all designed for different needs — ecology, hydroelectric power generation, navigation, public safety... The National Obstacles Referral (ROE) is the product of both centralisation, unification of existing data and data from new inventories and future updates. The ROE lists all the works listed on the national territory by associating them with limited information (single national code, location, typology) but common to all water and spatial planning actors. It also ensures the management and traceability of information from the various partners. This is an extraction on the territory of Occitania. For more information on the data, follow this link: https://www.sandre.eaufrance.fr/atlas/srv/fre/catalog.search;jsessionid=v9jpi9pv38inlbsi8h3rsz1f#/metadata/070df464-73d3-4c00-be2f-93f2a97ef8f5 The extraction of ROE in Occitanie is accompanied by a reduction in the number of fields needed for DREAL services. A specific attribute dictionary for this extraction is available for download. For more information, please refer to the SANDRE dictionary, also available for download.