ENVIRONMENTALLY FRIENDLY DRAINAGE PLANNING TO REDUCE FLOODING IN BANJARAN DISTRICT

• Main Author: Malaka, Abdan
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/55670
• Institution: Institut Teknologi Bandung

Banjaran is a densely populated area that is crossed by 1 major river and 6 tributaries. Due to its geographical position and conditions, this area is blessed with rainwater. However, there are frequent flooding problems and concerns in this area after heavy rains. For that, planned some primary drainage in 6 villages, a storage ponds, and suggested for the construction of home-base rainfall utilization ponds. The rainfall used in the calculation is the 5-year return period rain of 82.89 mm. Using the Nakayasu Method, calculate the flood discharge for 5 rivers which is then used to model the river flow to determine the flood water level. 150 segments of the primary drainage channel is planned that flows gravitationally, with outlets located in natural rivers. Modeling of the channel is carried out with the help of SWMM. Then for the storage pond, it is planned to have a capacity of 72418 m3, have functions to hold some of the flood discharge of the Cibanjaran river, as a groundwater catchment area, and water reserve for the dry season. The pond inlets opens at the elevation of +681.89 m at 1.7 m heigth, and closes when the pool is full. The volume and discharge of the home-base rainfall utilization ponds was also calculated to see how big the regional impact was. It was found that home PAH reservoirs can reduce run off volume by 33.67%, and drainage discharge up to 39.5%.