Reducing flood risk by effective use of flood‐peak polders: A case study of the Tisza River

Abstract

Between 1998 and 2006 a series of extreme flood events took place on the Tisza River and its tributaries. In Hungary, this triggered the development of floodpeak polders as a more cost-efficient solution of defense compared to raising the dikes. The recent analysis applies Monte-Carlo simulation-based quantified risk calculations with a cost-benefit type comparison. Results indicate that compared to the originally planned, 100-year return frequency flood that threats to topple the levees, lower flood levels already provide economic justification for polder use. Apart from the optimal timing of opening the floodgates, the controlled inundation of polders requires the consideration of its costbenefit effects as well. The development of the economic decision-support system for the controlled use of the flood-peak polders along the Tisza River provides an insight into the efficiency gains that a more informed, quantitative economic analysis can offer in risk reduction. The analysis reveals the potential for more efficient management of flood polders. The decision support of controlled polder inundation includes all the necessary information elements for the cross-sectoral comparability of impacts that is the foundation for any multi-purpose land management scheme that enables nature-based solutions.

Combining Flood Risk Mitigation and Carbon Sequestration to Optimize Sustainable Land Management Schemes: Experiences from the Middle-Section of Hungary’s Tisza River

“…The first report [20] explores the economic value of the flood peak reduction effect of the controlled opening of polders and an article based on it [17] presents the methodology of the calculation; it introduces a breakeven point flood frequency approach, above which (for less frequent, more severe flood events) the opening of a polder can be considered economically justified under current rules. In contrast to this, the present article examines the relationship between more frequent (that means lower peaking) floods and the use of the polders below the breakeven point; this is the probability segment of floods where the conflicts between the public and private use of floodplains (due to the presence or absence of frequent flooding) are concentrated.…”

“…Ref. [17] presented a detailed methodology for quantifying the flood risk mitigation effect of flood-peak polders with controlled inundation. The results prove that, from an overall societal perspective, it makes sense to allow more frequent use of flood peak polders, despite the significant event-based costs associated with inundation.…”

Mitigating floods and attenuating surface runoff with temporary storage areas in headwaters

“…Compensation for flood storage depends on the likelihood of flooding and damage within the retention area (Kis et al, 2022). In Europe, large scale flood alleviation projects have required considerable land take (3–250 km 2 ) (Glavan et al, 2020; Kis et al, 2022; Natural Water Retention Measures (NWRM), 2013; Ungvári & Kis, 2020). From a policy perspective, the cost of one‐off payments to landowners to compensate lost land or flood events from such large‐scale projects (Fenn et al, 2015; Kis et al, 2022) could be reduced by small TSAs that should incur less costs and provide additional benefits.…”

Reducing flood hazard by effective polder operation: A case study of the Golina polder

“…The redistributed flood risk applies to many areas worldwide (e.g., Huang et al 2007;Ungvári, Kis 2021), including the Warta River Valley from Konin to Sługocin (Wielkopolska region, Western Poland). Until the 1980s, the Warta River Valley was characterized by un-embanked floodplains, protecting the downstream areas against floods, e.g., the city of Poznan, the fifth most populous city in Poland.…”