Area defined by prefectural declaration of public utility (DUP) decree ensuring the protection of water catchments and their environment close to occasional pollution of chronic or accidental origin and diffuse pollution. These orders define three protection perimeters: the immediate protection perimeter (PPI), the close protection perimeter (PPR) and the distant protection perimeter (PPE).
Limit of the legally reserved space around the catchments used for drinking water supply, after the opinion of a certified hydrogeologist. Handicraft, agricultural and industrial activities, and construction are prohibited or regulated there in order to preserve water resources, avoiding chronic or accidental pollution. We can legally distinguish three perimeters: the immediate protection perimeter (PPI) where the constraints are strong (possibilities of prohibition of activities), the close protection perimeter (PPR) where the activities are restricted, and the distant perimeter (PPE ) to guarantee the sustainability of the resource.
According to article L1321-2 of the public health code, the catchment protection perimeter is defined as follows: "With a view to ensuring the protection of water quality, the act declaring public utility of water withdrawal works intended for the supply of human communities mentioned in article L. 215-13 of the environment code determines around the withdrawal point an immediate protection perimeter whose land is to be acquired in full ownership , a close protection perimeter within which can be prohibited or regulated all kinds of installations, works, activities, deposits, works, development or occupation of soils likely to directly or indirectly harm the quality of water and, the where appropriate, a remote protection perimeter within which the installations, works, activities, deposits, works, development or occupation of the land and deposits mentioned above may be regulated. "
Period of lowest water levels in streams and groundwater (usually summer for rainfall regimes).
Exceptionally low flow period of a watercourse, or exacerbation of its low water (sometimes assimilated to low seasonal flows). Low water is therefore considered to be a limited period in the year when the flows drop lower than a statistically calculated threshold value, function of each stream.
Station measuring groundwater quality at a water abstraction point where samples are taken for physico-chemical and bacteriological analyses ... to determine water quality.