Effectiveness of Situ for Ciliwung Flood Mitigation in Bogor Regency

Abstract

Bogor Regency is one of Regencies in Jabodetabek area that is experiencing rapid urban growth. This condition impacted the decreasing conditions of 39’s from 95’s urban small lakes or locally known as ‘situ’. This research aims to analyze the effectiveness of situ Kebantenan and situ Cikaret as Ciliwung flood mitigation measure in the Bogor Regency. The SWAT model was employed for quantification the water balance of situ and watershed management. The simulation results of the water balance analysis indicated that the monthly average of volume of Situ Kabantenan and Situ Cikaret (2008-2015) were 136,955 m3 and 508,907 m3, the annual inflow Situ Cikaret were 24,693,822 m3/year and outflow were 25,177,593 m3/year, precipitation were 648,520 m3/year, evaporation were 166,543 m3/year, delta storage (1,794) m3/year, respectively. The result of hydrological responses analysis on application of situ and watershed management scenarios that combined the structural and non-structural measures was the best scenario for decreasing maximum discharge at situ outlet which is decreased 41% discharge. So that, in order to enhance the effectiveness of situs for Ciliwung flood mitigation, the combination of the structural and non structural management of 13 situ’s in Ciliwung river basin within the Bogor Regency is recommended that can increase the storage capacity from 1.8 million m3 to 4.7 million m3.