Design of a drainage network for Kikindu market

Abstract

Kikindu market is one of the local markets located in the Northern division of Mbale city. It has been a victim to flooding whose cause is greatly aligned to the increasing storm runoff alongside with the poor drainage network. Factors such as increased impervious surfaces alongside high rainfall intensities have been accountable for the increased runoff which has in turn overwhelmed the existing drainage network. To cope up with the ongoing dynamics, a hydrological and hydraulic study. Flood analysis was done using the extreme weather distribution for 5, 10, 25, and 50year returns periods for analyzing the hydrological characteristics and whereas Arc GIS 8.2 was used for analyzing the hydraulic characteristics. The design criteria as per the MoWT drainage design manual (2010) was highly observed. HEC-RAS 6.7 software was used for modeling and simulating the different sections of the drainage network. The final design comprised of different channel sections that were to be constructed using stone masonry. Most sections of the drainage network had a trapezoidal shape and 808m was found to be the overall length of the entire network. The drainage network is expected to effectively and efficiently function for 20years with a 55.8% probability of non exceedence under different conditions such as proper solid water management and continuous maintenance.