Accompaniment table of the Allier

The Allier accompaniment table is part of the Allier alluvial table which meets the following definition: ‘Part of the aquifer, free or captive, in direct or indirect hydraulic connection with the river (here the Allier), and in which the exploitation of a catchment during a period of 90 days is likely to have an adverse effect on the flow of the watercourse’. Within this space are defined 4 zones of iso-impact, by the appreciation of the % of the pumped volume considered to be taken from the flow of the watercourse: 100-80 %: practically corresponding to a direct sampling in the watercourse, 80-60 % 60-40 % 40-20 % less than 20 % where the influence of pumping becomes little significant. It should be noted that in the law of the confluences of Dore and Sioule, the influence of a pumping is very difficult to estimate given the interactions between the tablecloths of Allier and tributaries.