Hydraulic Study on The Use of Gates to Improve Drainage Performance of Dadahup Lowland Irrigation Area

Abstract

Dadahup lowland irrigation area, known in Bahasa as Daerah Irigasi Rawa (DIR) Dadahup, is one of the Ex-PLG areas that has been now included in the food estate program. It has been experiencing low productivity, producing only 1.7 -2.9 ton/ha/year of paddy. Farming on lowland areas is often hindered by inundation during rainy season. Such problems were observed at Blok A5 of DIR Dadahup where inundation might last for a long time. Drainage was hindered since the water level in the channel, being at +1.4 to 1.6 m, was higher than the ground level whose elevations were +1.30 m for the right area and +1.00 m for the left area. Flow simulation by employing HEC-RAS is proposed to obtain a drainage system that can overcome this inundation problem. The use of gates in the secondary and tertiary channels was analyzed to improve drainage performance. The results show that by using gates and pumps can reduce the inundation area and maintain the water level in the channel according to cultivation needs. Such as in tertiary channel, the water level in the right tertiary channel can be maintained at +1.30 m ~ +1.46 m, and that in the left tertiary channel can be maintained at +1.12 m.

Land suitability studies for paddy cultivation in Dadahup Swampy Irrigation Area

“…The water system is influenced by three rivers: the Barito River to the east, the Mangkatip River to the west, and the Kapuas Murung River to the south. DIR Dadahup is located in zones II-b and III [8], where parts of the area are affected by tides in freshwater without any saltwater intrusion.…”

Analyzing the hydraulic performance of water gates due to the impact of extreme rainfall on tidal lowlands: a case study in Katingan rice fields area, Central Kalimantan

“…In Rotterdam, the Netherlands, water level control in the lowlands uses polders and pumps so that flood discharge does not flow into land or settlements [16]. In the Dadahup lowlands, Indonesia, the water gates decrease the water level in the land during the rainy season [17], and in the Anjir Serapat lowlands, combining gates and canal normalization decreases the area of inundation due to rainfall with a return period of 5 years [18]. Rice fields in the Katingan tidal lowlands have an essential role in maintaining rice sufficiency in Central Kalimantan.…”

Analysis of Mini Polder Performance for Improved Water Management in the Dadahup Swampy Irrigation Area

“…A total of 2,195.21 kilometers of irrigation canals underwent rehabilitation. This included 507.41 kilometers of primary canals, 41.97 kilometers of auxiliary primary canals, 444.82 kilometers of secondary canals, 80.18 kilometers of collector canals, 338.86 kilometers of tertiary canals, and 781.95 kilometers of quarter channels [3]. Additionally, 226 built sluice gates were included in this extensive rehabilitation effort.…”

“…Block A5 has come to the forefront as a testing ground for implementing mini polders, representing an innovative approach to managing water. Considering variances in ground elevation and operational convenience, it is imperative to partition the water management system into smaller segments or blocks [3]. A polder is a low-lying land that constitutes an artificial hydrological unit [4].…”

“…Many studies have been conducted on the water management system in DIR Dadahup, both at the macro and micro levels. The most recent research on the micro water management system in DIR Dadahup focused on a hydraulic study regarding using gates to enhance drainage performance [3]. Based on previous research, it is believed that one of the significant challenges in agricultural development in DIR Dadahup is the issue of inundation [3] and water management, particularly during the dry season [7].…”