Launched in 2010, the RhoMéO project aims to set up an Observatory to monitor the ecological status of wetlands in the basin. For this purpose, in 2011 a compilation of the key figures of the many existing departmental and regional inventories of wetlands were made.
Various obstacles had to be surmounted.
As the data were not all available in Geographic Information System (GIS), some approximations had to be used. Two departments (of the 22 located in this watershed) do not have an inventory of wetlands. Finally, the inclusion criteria-or not – of certain types of wetlands in the inventory were not the same from one department to another. For example, some took into account soil conditions (soil related criteria), some didn’t, some did not include large lakes and dams-reservoirs, others did and others only partly.
Despite these inaccuracies, a first synthesis was achieved, and provides orders of magnitude. The RMC watershed hosts more than 48,000 wetlands. Nearly 600,000 hectares have been identified. Also, given the departments without inventory and those which excluded thousands of acres of lakes and reservoirs, it seems reasonable to calculate a range of 650 to 750,000 ha. As an indication, it can be compared to a recent assessment: the total is higher than 17 out of the 27 Mediterranean countries recently analyzed in the framework of the Mediterranean Wetlands Observatory.
An improvement of this estimate will be possible when the latter departments have completed their inventories and a consolidation of GIS data will become possible. However, the order of magnitude is not expected to change significantly.