Stormwater Harvesting for Sustainable Rural Water Supply – a Case of the Mua Hills Settlement, Machakos County, Kenya

Abstract

Water is vital to all life forms on Earth (Hossain, 2015). This study on stormwater harvesting for sustainable rural water supply – a case of the Mua Hills settlement, Machakos county, Kenya aimed to investigate the implication of stormwater harvesting on the sustainability of the rural water supply system. Other objectives guiding the study included determining whether the existing water supply meets water demand in the Mua settlement, examining factors that affect water supply and demand in the Mua settlement, evaluating the potential for stormwater harvesting in augmenting rural water supply in Mua settlement, and to propose strategies that can be employed to ensure stormwater harvesting for sustainable rural water supply. The research also tested two null hypotheses: there is no significant difference between the existing water supply and water demand in the Mua settlement, and stormwater harvesting has significant potential for water supply in the Mua settlement. The study agrees with international, national, and local policy and legal frameworks regarding water resource management. The study was anchored on the game theory, systems theory, evaporation and transpiration theory, theory of natural resources, and theory of integrated water resource management. More specific essential concepts in the study are the concept of sustainability and the concept of the Internet of water things. The study applied social survey and descriptive survey designs involving both qualitative and quantitative methods. In the identification of key informants, a purposive sampling method was used. Stratified random sampling divided the study area into three groups based on the three sub-locations. For the selection of household questionnaires, business questionnaires, and Focus Group Discussions, simple random sampling was used to select the sample for the subgroups. The research found that in the Mua Hills settlement, water demand surpasses the water supply by 8.7m3/day as of 2024. This state manifests over time when the population keeps growing while no specific measures are taken to ensure the available resources like water are still sufficient. Stormwater harvesting on Mua Hill is greatly hindered by the private land tenure that allows residents to farm upstream, thus polluting any dams built. Based on the three criteria used for suitability for stormwater harvesting analysis: slope, cadaster analysis, and land cover analysis, there is potential for stormwater harvesting. Using Multi-Criteria Decision Analysis (MCDA), 29.64% of the settlement was delineated for total conservation as it was found to be entirely unsuitable for development. The study concluded that the Mua Hills settlement, like other rural and urban areas, has a water demand that surpasses the water supply. Consequently, stormwater harvesting on Mua Hill is greatly hindered by the private land tenure that allows residents to farm upstream and the failure of the government to construct all delineated dams. The study recommended the construction of small dams and water pans upstream to supply water to the settlers downhill. Complete conservation would ensure enough water for the Miwongoni dam downstream. On strategies to ensure stormwater harvesting for sustainable rural water supply, the research recommends developing a catchment planning and management policy, formulation of a Catchment Management Strategy, and a Catchment Management Unit. However, the research noted that there still is a lack of a catchment-based approach to water resources to guide the conservation and protection of these areas. Thus, recommended further research on stormwater harvesting policy and catchment management integrating it with land and land use management aspects.