Using GIS in urban storm water management: a case study of south c estate, Nairobi

Abstract

With the growth of towns, storm water management has become more and more challenging especially in the urban areas of developing countries. This is characterized by urban explosion over a short period of time giving rise to unplanned urban development patterns, inadequate provision of storm water infrastructure a midst the rapidly increasing developments. This therefore constitutes major obstacles for effective urban storm water drainage. Storm water infrastructure in Nairobi is facing increasingly heavy strain and increasingly frequent failure from storm water and this is mostly evident during the heavy rains. Due to poor storm water drainage systems, roads in Nairobi have been facing flooding issues over the years which not only inflict economic loss but also threaten public health caused by storm water pollution. This study focused on storm water drainage in South C Estate in Nairobi. South C is one of the areas that suffer every time it rains, roads in this area are very quickly flooded becoming impassable and houses become flooded causing property loss and damage. The existing storm water infrastructure was investigated using GIS and the role of the surrounding community to this problem was also examined. GPS data collection and field verification was used to establish the status of the existing storm water drainage. Secondary data was used to support the primary data collected. ArcGIS software was used to carry out data analysis. Comparative analysis was carried out using this software. Hydraulic analysis of the study area was also carried in order to understand the interaction of natural topography with the storm water drainage infrastructure. The aim of this study was to encourage the Nairobi County Council to implement GIS systems as a monitoring and decision-making tool to improve storm water management in Nairobi and other Counties. This study would also assist in education of the public on Best Management Practices for storm water management.