Agricultural production and flood control dry detention reservoirs: Example from Lower Savinja Valley, Slovenia

Abstract

Dry detention reservoirs are frequently used as a measure to alleviate flood risk. When implemented on agricultural land, they decrease the productive capacity of a rural landscape and negatively impact soil characteristics, crop quality and quantity, agricultural infrastructure (i.e., irrigation equipment), and agro-economics. The Slovenian government prepared a Detailed Plan of National Importance to ensure flood safety in the Lower Savinja Valley. The proposed plan foresees the implementation of a chain of 10 dry reservoirs (520 ha of agricultural land) to provide a higher level of flood protection for the cities of Celje and Laško. We explored how economic calculation can adequately address flood risk management initiatives and prevent adverse effects on high-quality agricultural land. The results of agro-economic scenarios for the study area showed that expected damage to agriculture production (crop yield) in a worst-case flood event occurring during the growing period would be EUR 1.7 million. The most exposed farms would suffer damage in the range of three to five average annual salaries. These agro-economic findings indicate the need for discussion on agriculture-focused mitigation measures before the construction of flood protection measures.