Simulation of Catchment Area, Water Storage and Pump Capacity in Polder Drainage System

Abstract

Tidal flooding that occurs on the northern coast of Semarang City is caused by high rainfall, sea water level rise, and is exacerbated by land subsidence. Handling of tidal flooding is recommended with a polder system. Tidal flood management is made of several alternative retention ponds located in the Banger region so that water can flow in the new retention pond at the pump into the river so that the water goes to the sea. The purpose of this study is to formulate a correlation between catchment area, retention pool and pump capacity. Rainfall-runoff as well as hydraulic parameters were computed and simulate using SWMM software Version 5.1. Based on the analysis results, it clearly shows that, the flood discharge of 24 m3/s can be overcome by integrated pond structure with pump configuration. Alternative 1 retention pool 1 with a storage volume of 15,000 m3, Alternative 2 combined ponds 1 and 2 with a storage volume of 11,400 m3, Alternative 3 combined 3 ponds 1, 2 and 3, storage volume of 14,200 m3, alternative 4, is a combination of the three retention ponds above, with a storage volume of 64,300 m3. The water level in the pond is maintained not to overflow when pumping is carried out with the addition of the pool area, it will further reduce the capacity of the pump that is turned on with certain configurations on the pump operation schedule.