Water supply catchment areas

Catchment areas of water supply in Bavaria. Known, already demarcated catchment areas were tested for plausibility using uniform criteria and specifications throughout Bavaria, if necessary revised or, if necessary, redefined even small-scale (processing scale 1:25.000 or smaller). A small-scale initial demarcation was made for water production plants (WGA) without already known catchment areas. 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 the site. The collected area data is intended for use on a small scale (≤ 1:25.000) and provides an initial overview of the location of the water supply basins. The limitation is usually based on hydrogeological, mean hydrological and anthropogenic influencing variables (e.g. hydraulic permeability, groundwater flow direction, groundwater regeneration, abstraction).
(Note for the common presentation of river basins with water protected areas: In principle, the catchment areas are demarcated and presented in relation to the individual WGA. Total and interactions between neighboring WGAs remain eighth in this methodology. However, a water conservation area can be established for several WGAs. In this respect, concrete sum and interactions of the sub catchment 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 protection area (processing scale approx. 1:5.000 or greater), the hydrogeologically hydraulic boundaries of an underlying catchment area or its sub-areas must be enclosed with quality-relevant risk relevance. Likewise, worst-case scenarios such as summer maximum withdrawals at low groundwater levels or altered current conditions (inflow direction, gradient) must 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 protection zones must be adapted to the local conditions (e.g. parcel boundaries). For this reason, in particular in the area closer to the version, the water protected areas generally extend beyond the river basins shown.
As a result, in individual cases, due to this above classification or by different processing levels of water conservation area and catchment area, the shown WGA-related catchment areas may be smaller than the water protected areas. In these initially implausible cases, it is regularly necessary to know exactly the reasons for this.)