ASSESSING THE POTENTIAL OF STORMWATER IN AUGMENTING DOMESTIC WATER SUPPLIES IN KAPSERET SUB-COUNTY, UASIN-GISHU COUNTY, KENYA

Abstract

Water is essential for human survival and development. However, many rural communities continue to experience various domestic water supply challenges. The purpose of this study was to explore the potential of stormwater as an additional source of water for domestic use in Kapseret Sub-County (KSC), Uasin Gishu County. The specific objectives were to assess domestic water consumption, to examine the potential of stormwater in KSC, to establish determinants of stormwater utilization (SWU) and to identify challenges in stormwater management (SWM). The study targeted households in rural settlements within KSC where a total of 404 households drawn from a population of 59,746 households were interviewed. Sample size was determined using Yamane‘s sampling formula. Stratified random sampling was adopted. Both primary and secondary data sources were utilized. Qualitative and quantitative data from questionnaires, interviews, observation, photography, Remote Sensing imagery, Digital Elevation Models (DEM) and document analysis were used within the mixed approach design. To establish domestic water consumption, data from household questionnaires was collected and analyzed. Computation of mean was used to determine household and per capita domestic water consumption, while linear regression analysis was used to identify factors influencing household domestic water consumption. To estimate stormwater yield in Kapseret basin, rainfall, soil type, Land Use Land Cover (LULC) and slope data was utilized. Rainfall and temperature data was acquired from the Eldoret Airport and Kapsoya Meteorological stations. ArcGIS was used to process soil data, DEM, and LULC MAPS. Satellite imagery was downloaded from USGS website and processed using ArcGIS. Soil and Water Assessment Tool (SWAT) performed the maps overlay and estimated stormwater yield, and applied Multi-criterion analysis to map suitable sites for stormwater harvesting (SWH). Binary logical regression was utilized to identify factors influencing SWU. To determine the challenges of SWM, binary logistic regression and frequency analysis were utilized. The study established that daily household domestic water consumption was 149 liters and 168.8 liters in the dry and rainy seasons respectively, while per capita domestic water consumption was 41 liters and 48 liters in the dry and rainy seasons respectively. Factors that influenced household domestic water consumption include income, household size, distance to water source, main housing type, education level of household head and capacity of water tank. Secondly, stormwater yield for the year 2019 was estimated as 353.38mm. Suitable zones and four sites for SWH were also identified. Thirdly, determinants of SWU include access to stormwater, level of awareness, outdoor uses, and perception that stormwater is unclean. Finally, the challenges to sustainable SWM include unavailability of land, insufficient financial and technical capacity and support, and lack of education on benefits and strategies of SWM. This study concluded that water supply in KSC is inadequate in the dry season. In addition, the potential for stormwater to augment existing water sources is high but remains untapped. In addition, access to stormwater would increase stormwater utilization. Finally, there is a lack of supportive institutional framework for SWM in KSC. The study recommended that authorities need to enhance rural water supply to households and prioritize development of SWH infrastructure to harness stormwater. Finally, communities must be educated on end uses of stormwater and on SWM strategies and benefits.