(1) the immediate protection zone, with a radius of 2000 m around the lake including water, its islands and coastal strip.
(2) the near protection perimeter, limited to intense vulnerability zones in the immediate sub-basins of lake.
(3) the distance protection perimeter has been estimated to the whole catchment in order to take into account diffuse pollution.
The zone I or immediate protection perimeter was established to a radius of 2000 m around of reservoirs, unlike to Marchal (2007) and Lallemand-Barres and Roux (1989).
Which suggested limiting this protection zone at 100 m, but they worked in mountainous zone, where the slopes bordering reservoirs are high. Thus, this first barrier includes reservoir, its islands and coastal strip.