The Warning and Alarm Plan Rhine (WAP) distinguishes between warnings, information and search reports.
The International Main Alert Centres (IHWZ) issue warnings in cases of water pollution incidents implying substances noxious to water, if the amounts or concentrations concerned may detrimentally impact the water quality of the Rhine or drinking water supply along the Rhine and/or are liable to raise great public interest.
Information is issued in order to give the IHWZ objective, factual and reliable information independent of the media. Furthermore, the IHWZ inform all Rhine bordering countries in cases of excesses of guidance values. As a precautionary measure, information is also passed on to the drinking water works.
Search reports are issued, in order find the polluter of the Rhine in cases not located within the area of responsibility of an IHWZ.
The report is only available in German, French and Dutch.