Mini Polders as Alternative Flood Management in the Lower Bengawan Solo River, Indonesia

Abstract

AbstractThe villages of Sumbangtimun and Kandangan, in the Lower Bengawan Solo River, Java, Indonesia, are regularly flooded. These flood‐prone areas are located in a meander of the river with low natural embankments. Flood damage losses were estimated at US$190 000 in the wet season of 2007/2008, with the largest losses in the agricultural sector, due to floods which came early before the harvest season. In this article, we explore the potential of a set of mini polders for the different types of land use, i.e. rice fields, tree crop plantations and settlements, each with different tolerances to flooding, as an alternative way to manage flood risk. The HEC‐RAS and PondPack hydraulic models were used to design an appropriate mini polder system and its operational procedures. According to the results of the model simulations, the inundation by a flood with a 2‐year return period is about 1 m deep, over 2 days, with 250 ha flooded. The inundation by a flood with a 10‐year return period is about 2.5 m deep, over 3 days, with 383 ha flooded. The models were also used to design a retention pond and pumping capacity. Copyright © 2017 John Wiley & Sons, Ltd.