River Flood Control Planning for Rice Fields in the Lower Lumu Watershed Mamuju Tengah Regency Mahmud Achmad (a*), Samsuar (a), and Jayadi (b)
(a) Department of Agricultural Technology, Universitas Hasanuddin,
(*) m.achmad1970[at]gmail.com
(b)Department of Soil Science, Universitas Hasanuddin
Abstract
New rice fields in the lower Lumu catchment area were experience flooding during heavy rainfall events that affected lack of productivity of paddy field. Mamuju Tengah has potential rice field that needs simple construction to protect them from river floods and enable cultivation in the area. The purposes of this study are to evaluate land and hydrological condition of the catchment and to create embankment for river flood protection of rice fields along the Lumu river. Land suitability and hydrological analysis were conducted to evaluate the condition of the site. The design of river embankment was based on hydrological analysis, and create financial planning for the river flood control in Mamuju Tengah Regency. In terms of soil pH, even some area in Pasapa and Bojo reacted slightly acidly, but most were classified as not saline. The depth of peat in the land is between 0.10 - 1.50 m with most area is shallow and still suitable for rice cultivation. Preventing flood and drainage channel are best solution for the land. River embankment was chosen as solution and the design was done using SNI 03-1724-1989 for Hydrological and Hydraulic Planning Procedures for Buildings on River and SNI 03-2415-1991 for Method of Calculation of Flood Discharge, while financial planning was calculated using SBU 2020. Rainfall with return period of 50-year flows water in Lumu river about 11,670.9 cumecs while river capacity is only 901,272 cumecs. Flood has protected by creating river bank along the river levee 4,079 m long in Pasapa village and 3,415 m long in Bojo village. The construction needs financial support approximately 2.35 billion rupiah.
Keywords: flood control, river embankment, paddy land, peat soil
