ANALYSIS OF STORM WATER RUNOFF DRAINAGES IN ADDIS ABEBA CITY: CASE STUDY: CMC ROAD

Essentially, drainages are structures that collect, convey and discharge runoff from the surface of road pavements and adjacent catchment areas to artificial or natural waterways like ditches, channels, rivers, streams, ponds, lakes etc. Drainage problems occur either due to design, usage and/or construction defects. As observed in most parts of Addis Ababa city roads, storm runoff overflow drainage channels, spew debris, inundate pavements, block traffic movement and cause accidents. Water on the pavement can interrupt traffic, reduce skid resistance, increase potential for hydroplaning, limit visibility due to splash & spray and cause difficulty in steering a vehicle when the front wheels encounter puddles. Moreover, since the light train transport service uses electric power to operate, runoff flow over the rails could pose electrical hazard to passengers. The objective of the research is, thus, to identify the main problems of storm runoff drainages and of course investigate the causes and suggest viable solutions to curtail similar occurrences and mitigate the adverse effect. Thus, data is collected using; Questionnaire, field survey/site investigation, observation, interviews, photographs, public discussions, etc. hence compiled and analysed through Wrangling, cleansing, and shaping data, using Excel’s analysis tool pack. Six offices that have direct and indirect dealing with storm runoff drainage and residents living around the corridor of the study area were contacted and given the questionnaire. The finding is that the main problem associated with storm runoff drainages are clogging by debris, rubbish & sedimentation and the causes are identified to be inadequate study of the soil & topography, insufficient channel size, dumping of rubbish into the channels by residents and poor construction workmanship