Evaluation Of Urban Drainage System And Its Resilience; A Case Of Calalaqa Subcity Bishoftu Ethiopia.

Abstract

Urban flood resilience is defined as the ability of a city and its constituent systems. The improvement of flood resilience has become an important means for cities to resist flood risks. The study aims to evaluate urban drainage system and its resilience using multi source data in Calalaqa Sub city. Recently, city drainage system along road is facing broad water logging during the rainy season as result of this serious problem of drainage systems. To address the problem specifically study, focus on Investigate and map the flood risk in the Study area. Designate the measures taken by the community and the government in mitigating flooding hazards in the area. The research was carried out using with mixed approaches (quantitative and qualitative) applying Multi-criteria and weighted overlay based on k-means clustering. Data were collected using Key Informant interview and household survey from flood risk areas of the city. From inspection of LULC it is noticed that majority of the study area has the Farm land and urban Built-up land cover. A vegetation or forest cover, slows down and reduces the amount of runoff while urban land cover which is characterized by paved and impermeable surfaces absorbs no water and increase runoff and therefore increases the probability of flooding. The findings revealed that the level of flood risk areas lacked basic infrastructures and had a greater level of perception as compared with low flood risk area. The result of the assessment also disclosed that heavy rain, absence of protective or retaining construction and its maintenance, and poor urban drainage structure were the main perceived causes while housing damage and destruction of household equipment, loss of infrastructure and health problems were effects of flooding in the City. The preparedness and response measures to protect and minimize the flooding hazard found were householders’ evacuation from their houses, filling sand in bags and placing around the edges of the premise as well as making a retaining wall-like structure with a hollow block despite it was not strong. In flood protection measures and Early Warning System, the support given from government and non-governmental organizations was inadequate. Thus, the government, community-based organizations and residents should take sustainable strategies for short- and long-term adaptation and mitigation measures.