ASSESSMENT OF STORM WATER DRAINAGE SYSTEM IN CASE OF CHIRO TOWN, WEST HARARGHE, ETHIOPIA

Abstract

The main objective of this study was to assessing the existing chiro city storm water drainage problems with respect to its hydraulic performance. The methodological approaches employed in this study include; the identification of the existing storm water drainage network flow capacity, and delineation of contributing areas. Storm water drainage problem is one of the major challenges facing many urban problem in Ethiopia. In general the chiro town is in particular problem of drainage system. So, the study focuses on the assessment of storm water drainage system in chiro town using by statistical analysis, was applied to analyze the existing condition system and to analyze the peak discharge with two common frequency analysis techniques were used to develop the IDF relationship from rainfall data of these regions are Gumbel and the Log Pearson III (LPTIII) distribution. Probability distribution functions were analyzed and identified using Microsoft Excel. A statistical analysis was applied to analyze the existing condition system and to analyze the peak discharge for the town and to fix the diameter of the channel. The method used to identify problem by investigated direct field data collection from site visited. Design of the study area is evaluated computation method used in ERA drainage design manual. The result of this thesis the drainage structure has not properly designed to solve the storm problem at study area and at this catchments. It has required redesign and reconstruction for the existed and it required additional storm drainage system. Finely drainage system is redesign required for different catchment in existed and for future. Additionally managing and improper construction alignment with master plan of town to according to avoid the problem periodic cleaning and modification of slope is recommended