Hydraulic performance of mini polder water management in flood management in Tabalong District, South Kalimantan

Abstract

Flood disaster is a common problem, especially in densely populated urban, coastal, and basin areas, respectively. This leads to the development of the Mini Polder design, which is used to solve the problem of flooding in agricultural land. The design is projected in lebak swamp in Ampukung village, Tabalong Regency, Indonesia, covering an area of 393 Ha. Therefore, this study aims to determine the hydraulic performance of mini polders in flood management, within Tabalong District, South Kalimantan, Indonesia. Using Hec-RAS in the planning stage, the results showed that a dike was produced with an elevation and a width of +10.30 and 4 m, based on the Q25th flood discharge of 514.37 m3/s. Furthermore, the construction of a channel around the land was planned as a replacement for the retention pond, due to the efficiency of excavation and stockpiling. The channel also functioned as a flood reducer, which approached water sources to the rice fields or community plantations. By excavating the existing outlet and rehabilitating the door building, the channel normalization was subsequently carried out. For emergency conditions, a portable water pump was needed for water supply and disposal of the Tabalong river, during the arrival of the dry season.