STUDI ALTERNATIF PERENCANAAN TUBUH BENDUNGAN PADA BENDUNGAN MBAY DI KABUPATEN NAGEKEO PROVINSI NUSA TENGGARA TIMUR

Abstract

A dam is a construction built to prevent the discharge of water into a reservoir, lake or recreation area. The main building of the dam is the dam body. The Mbay Dam in Nagakeo Regency is located in East Nusa Tenggara Province and is a relatively dry area, the available water sources are relatively few compared to other areas. From the results of the materials available at the location and around the dam planning, the body of the Mbay dam is planned as a vertical core zonal type embankment dam. The aim of preparing this thesis is a solution to plan the dimensions of the dam body which are technically feasible to build in accordance with the problem of lack of raw water supply, irrigation water for rice fields, and the absence of water retaining structures. The method used in this study is hydrological analysis, dimensional analysis and stability of the upstream and downstream dam bodies. Mbay Dam is located in Nagakeo Regency in Rendubutowe Village, South Aesesa District, East Nusa Tenggara. The results of the flood discharge magnitude designed for the Mbay Dam with a return period of 1000 years are Inflow = 115.48 ð‘š3/ð‘‘ð‘¡, and Outflow = 22.40 ð‘š3/ð‘‘ð‘¡. The capacity of the Mbay Dam is 518.11 ha, at an altitude of +411.00 m. Dimensions of the dam body with guard height = 3 m, lighthouse width = 13 m, dam crest elevation = +1146.15 m, upstream slope = 1:2.7, and downstream slope = 1:2.2, body seepage stability dam 0.000252 x 10-5 ð‘š3 /ð‘‘ð‘¡ < 2.309 ð‘š3 /ð‘‘ð‘¡ (safe). Upstream slope stability when the reservoir is empty, Normal: 3.15 > 1.5 Upstream slope stability when the FWL water level is high, Earthquake: 1.31 > 1.1.

 

Keywords: Dam, Hydrology, Rainfall, Stability Analysis