zone 1 includes the most constraining conditions, because it corresponds to nearest contour of water taking. In order to avoid deterioration of installations and dumping of pollutants substances in the proximity of water taking, no activities other than those relative to exploitation and installations upkeep are authorized (Garouni and Merzouk, 2004). In the case of surface water, the establishment of this perimeter is difficult because of different activities practiced on the water (Fiquet, 1997). It therefore is limited to water plan and them treatments installations if those are situated in its proximity (Marchal, 2007) and (Garouni and Merzouk, 2006).
The zone 1 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.