Storm water management challenges and their environmental impacts – A case study of Ongata Rongai Town

Abstract

The issue of storm water management is a big problem in developing countries. In Africa, particularly in Kenya, urban planning in many developments is locally done without consulting experts. It is for this reason that later on issues of poor drainage affect the socio – economic activities of the dwellers. In Ongata Rongai, Kenya, the effects of heavy rainfall floods the settlements situated in the lower parts of the town. The effects of such rainfall are manifold; sanitation, material, economic and environmental impacts. This project investigated and assessed mainly the environmental challenges and effects associated with storm water management in Ongata Rongai urban centre. Specific objectives were to analyze the bacteriological composition of storm water due to poor sewage disposal; to assess the socio - economic effects of storm water in Ongata Rongai and its management and to evaluate the effectiveness of the National Water policy (2012) in enhancing storm water management and pollution control in Ongata Rongai. The research study adopted an experimental and survey research design where the experimental design involved analysis of storm water samples collected from three locations in the three clusters of the study area. The survey design adopted a structured questionnaire that targeted a population of 2000 households in Laiser Hill sub-location in Ongata Rongai. Spatial clustering of these households was done depending on their residential and commercial characteristics to arrive at the three clusters and the sample size of 90 in the study area. Quantitative primary data gathered directly from the households was further subjected to analysis using descriptive statistics and inferential statistics (Pearson‟s chi – square) to test the hypotheses with the aid of statistical software called Statistical Package for Social Sciences (SPSS). The study found out that environmental pollution challenges in Ongata Rongai is an issue of concern because of lack of established sewerage system to dispose septic tank contents and inadequate storm water drainages. E coli detected in sampled storm water during the bacteriological analysis is a clear indication of human fecal waste disposal and contamination. Storm water related diseases such as malaria and diarrhoea have high case recordings at the area‟s government health centre while there are also numerous court cases pertaining to environmental pollution through sewage disposal as given in appendixes 8 and 9. 3.841 at 0.05 ) between storm water management challenges and the social economic development of the area. Poor planning, inadequate storm water drainages and a lack of established sewerage systems were the main management challenges of storm water in the study area. Implementation of the National water policy (2012) was found to be affected by the limited storm water management instruments in the study area: poor planning by the county government, the residents are hardly involved in planning and water management. Majority of the respondents lacked awareness and are not informed about storm water management and flooding issues in the area. The study concluded that storm water management challenges affect the social life (e.g displacement of populations and diseases), and economic life (e.g damage to infrastructure, goods and services) of the residents living in Ongata Rongai. This is common whenever there is adequate precipitation especially the two rainfall seasons as given in figure1.5. It recommended the construction of new drainages, unblocking of the existing drainages, launching public campaigns to educate the public about storm water management and pollution control, and implementation of the polluter pays principle to policy makers as one way of curbing these challenges.