Optimization of the Retarding Basin Maximum Capacity to Reduce Flood Peak Discharge

This research intends to analyze optimal storage capacity of retarding basin (Vk optimal) in reducing the flood peak discharge (DQp) in the downstream control point. The methodology consists of simulation in several placing of retarding basins (RAK) and various maximum storage capacity (Vk) for various flood return periods (QT). This research is conducted in agglomeration urban area of Wonosari, Gunungkidul Regency, Daerah Istimewa Yogyakarta-Indonesia. There are planned 5 retarding basins that are Purbosari, Jeruk, Kepek, Purwosari, and Trimulyo. The optimal result of maximum storage capacity (Vk) due to the reduction of flood peak discharge (DQp) for the retarding basin of Purbosari (RAk = 7.01%) produces the optimal storage capacity (Vk optimal) about 886.45 x 103 m3 and it can reduce the flood peak discharge (DQp) about 6.20%; however, for the retarding basin of Jeruk (RAk = 8.65%) produces the optimal storage capacity (Vk optimal) about 1000.01 x 103 m3 and it can reduce the flood peak discharge (DQp) about 7.56%; for the retarding basin of Kepek (RAk = 21.34%) produces the optimal storage capacity (Vk optimal) about 1069.88. x 103 m3 and it can reduce the flood peak discharge (DQp) about 14.23%; for the retarding basin of Purwosari (RAk = 60.11%) produces the optimal storage capacity (Vk optimal) about 1266.92. x 103 m3 and it can reduce the flood peak discharge (DQp) about 26.45%; and for the retarding basin of Trimulyo (RAk = 66.52%) produces the optimal storage capacity (Vk optimal) about 1266.94. x 103 m3 and it can reduce the flood peak discharge (DQp) about 29.27

Capacity optimization · Flood control · Flood myth · Hydrology (agriculture · Structural basin · Flood Risk Assessment and Management · Water and Land Management · Wetland Management and Conservation