Studi pengendalian banjir batang kuranji Padang Sumatera Barat

Abstract

Kuranji River is located in the city of West Sumatra Province. Kuranji River is 17km length and has 135,44 km2 river flow. Kuranji River has three air source From Padang jernih, Padang keruh, and Limau Manis. Flooding issues take place on the downstream Kuranji River. Besides the lack of channel capacity, the damming affected by PDAM that causes the water surface rises could cause the flooding as well. From central until downstream section of Kuranji River, it is an over populated area along the sides. The water runoff caused by the flood gives many disadvantages to the neighbourhood both material and non-material. Therefore, it is required a flood control efforts for Kuranji River especially for the downstream section. In this study, hydrological analysis is conducted starting from determining region rainfall with Thiessen Polygon Method, rainfall design with frequency analysis, and the flood discharge with HSS SCS. Based on the hydrological analysis, peak discharge input for Kuranji 1 is 196 m3 / s and for the 2-year period and 454.7 m3 / s the 10-year period. The input for Limau Manis is 90,5m3 / s for the 2-year period and 208.8 m3 / s for the 10-year period. Based on the results of hydraulics analysis, it is determined that the capacity is the same as the discharge for 2-year period. However, in the upstream, damming occur until 1 km in the upstream. As a result, flooding occur along 1 km. For the result of the simulation of the discharge of 10-year period, generates flood highest water surface elevation 4,2m in the upstream. To prevent the flood, a dyke is built along ± 4.1 Km with disposals 5,4m Maximum elevation. A dyke is placed 10m from the river channel.