Development of Sustainable Detention Ponds for Flood and Sediment Control in Urban Areas

Abstract

Muddy floods often occur in Indonesia as a side effect of urban development. Flood and sediment control facilities have been so far developed separately. Flood is controlled by reservoirs, while sediment is trapped by checkdam. The objective of this paper is to develop an integrated system between flood control and sediment trap analytically. The system consists of detention pond equipped with perforated spillway tower. Optimization is carried out on the dimensions of spillway tower, the diameter, number and layout of perforation orifices to obtain the highest trapped sediment and flood peak reduction for a certain pond capacity. The research was conducted in the Meteseh sub-watershed, located in Semarang. The results indicated that the position and arrangement of the orifices in the spillway tower affect sediment trap, while their size and number affect the reduction in peak discharge. The proper size, number, posistion and arrangement of orifices on the spillway tower be able to trap sediment and reduce flood discharge as high as 80%, and 24% consecutively.