Berechnung von Mehraufwand und Minderertrag infolge des Trinkwasserschutzes im Wald

Calculation of additional expense and reduced revenue as a result of drinking water protection in the forest A good portion of the drinking water in Switzerland originates from groundwater wells in the forest. Within the framework of the Water Protection Ordinance these forest areas are designated as groundwater protection zones (core zone, S1; inner protection zone, S2; further protection zone, S3) to protect the drinking water supply against contamination. The designation of a forest area as a protection zone is connected to prescriptions and recommendations influencing forest management and causing additional costs for forest enterprises. On behalf of the Federal Office for Environment, an Excel tool has been developed. With this tool, the additional expense and reduced revenue can be calculated quickly and easily. To reflect the requirements in the tool, courses of action were defined, as they occur in forest management (e.g. no chemical wood treatment in the S2 and S3 zone, utilization of non-polluting fuels and lubricants). Subsequently, these courses were converted into mathematical formulae quantifying the additional costs. Three harvesting methods common in forest management were thereby distinguished, a motor-manual harvesting method, a fully mechanized harvesting method and a harvesting method for steep slopes. The results calculated with the drinking water protection tool can form an essential basis for the discussion on compensation payment for water services from forest management and provide a better communication between forest managers and water suppliers. However, the results of the tool are to be regarded rather as guidelines and should not be taken as absolutely.