Utilization of Fishponds as Retention Areas in Flood Risk Management

Abstract

In addition to their importance for biodiversity and food production, Austrian carp ponds fulfill essential hydrological functions. Water retention, in particular, is becoming increasingly important, both during dry periods and during heavy rainfall events. During the floods in September 2024, which severely affected parts of Lower Austria, it was observed regionally that ponds can retain significant amounts of water and thereby reduce peak runoff. Due to the preceding dry spell, many ponds had water levels below their maximum capacity. In addition, following relevant weather warnings, pond operators lowered the water levels in the other ponds. As a result, the ponds of Lower Austria were able to retain a considerable amount of water.