Watercourse mapping in Haute-Garonne

In order to raise awareness of the parts of the hydrographic system that are to be considered as watercourses (EC), the Government’s instruction of 3 June 2015 asked the services to draw up a comprehensive mapping in areas where this is technically feasible within a reasonable time frame and in other areas, to clarify the methodology for the identification of rivers.

Process for determining the CE type (TYPE_ECOUL attribute):
The way to determine it is indicated in the field “NAT_IDENT”:
— “analysis”: first “tri” on map analysis carried out in 2015.
— “CPC”: Some sections have been further analysed using, for example, aerial photos.
— “terrain”: rankings following a field visit carried out by the DDT (following classification challenge)
— ‘CEC’: rankings following a meeting of the watercourse commission in the field (following classification challenge and difficulty of arbitration at DDT level)

Regulatory basis = L215-7 of the Environmental Code. A prefectural decree should follow (request from the director).