Water supply catchment areas — WMS

Catchment areas of water supply in Bavaria. Known, already defined river basins were checked for plausibility using uniform criteria and specifications throughout Bavaria, or, if necessary, revised or, if necessary, also small — i.e. rough-scale (processing scale 1: 25,000 or smaller) newly delineated. For water extraction plants (SCIs) without an already known catchment area, a small-scale initial demarcation was made. The processing was carried out taking into account the data bases available at the Water Management Office (WWA). In addition, no investigations were carried out on site. The recorded area data are intended for use on a small scale (≤ 1:25,000) and provide a first overview of the location of the catchment areas of the water supply. The limitation is usually based on hydrogeological, medium hydrological and anthropogenic influencing factors (e.g. hydraulic permeability, groundwater flow direction, groundwater regeneration, extraction). (Note for the joint presentation of river basins with water protected areas: In principle, the catchment areas are defined and presented in relation to the individual ECIs. Sums and interactions between neighbouring ECIs remain eight in this methodology. However, a water reserve may be established for several ECIs. In this context, specific sums and interactions of the sub-basin areas must be taken into account in the design. In the case of large-scale, i.e. detailed processing for the design of a water protected area (processing scale approx. 1: 5,000 or larger) the hydrogeologically hydraulic limits of an underlying catchment area or its subareas must be enclosed with a quality-relevant risk relevance. Likewise, worst-case scenarios such as summer maximum withdrawals at low groundwater levels or altered flow conditions (current direction, gradients) must also be taken into account in order to achieve a sufficient level of detail for the delimitation of the WSG. With regard to the enforceability of the Water Protection Area Ordinance, the design of the water protected area or the protected zones must be adapted to local conditions (e.g. parcel boundaries). For this reason, in particular in the more detailed area, the water protected areas, i.e. R., extend beyond the river basins shown. As a result, in individual cases, this classification above or by different processing levels of water protected area and catchment area may lead to the fact that the listed EGA-related catchment areas are smaller than the water protected areas. In these initially implausible cases, it is regularly necessary to know the reasons for this.)