Meteorological support for anticipatory water management

Living with water is second nature to the inhabitants of the Netherlands. Managing water both as a resource and as a threat is a vital concern to the country. The responsibility for regional water management lies with the Dutch Regional Water Authorities. Their basic philosophy of a balance of safety and economic interests requires a sophisticated control and decision support system, with high quality meteorological inputs. The Royal Netherlands Meteorological Institute KNMI in conjunction with the Dutch Association of Regional Water Authorities has developed a warning system for extreme precipitation in support of anticipatory water management. Radar observations, short range deterministic forecasts and medium range ensemble predictions of precipitation are combined with risk profiles of individual water control boards in an automatic system, that warns of possible conditions outside normal control. This article describes the current operational system and presents examples of its application. A first evaluation of the possible value of this system, that essentially decouples meteorology and hydrology, is discussed, based on a first evaluation of the reliability of the precipitation forecasts. Finally, the article presents the current development of an extended system that uses combined probabilities of precipitation with wind, surge and river level forecasts to more accurately define risk conditions.