Impacts of instream sand harvesting on water supply, a case study of river Thwake, Makueni County

Abstract

This paper examines the impact of sand harvesting from rivers on the environment, water quality and quantity along Thwake River, Makueni County. Sand acts as a safe aquifer for water flowing below and through it. Removal of sand results in destruction of underground aquifers and loss of safe water. Sand scooping adversely affects surface water quality and quantity and damages the aquatic ecosystem. Haulage of sand by heavy trucks causes environmental degradation by accelerating soil erosion and affecting soil stability. Storage of sand causes destruction of surface areas through clearing of vegetation and uses land that could be used for agriculture. Related social and health problems include prostitution and high school drop-out rate leading to serious social and health problems. The beneficial effects of sand harvesting include local employment; however, the share of monetary benefits to locals is minimal. The results show that the local community gains the least from sand harvesting, but stands to suffer the most if the degradation of the river system continues. Suggestions are made for safe and sustainable methods of managing sand harvesting, in which greater local involvement and stricter enforcement of regulations to protect the environment are vital. Therefore, the protection of water resource from destruction through activities such as sand mining is paramount for the survival of both present and future generations. This research is a survey type of a research and employs quantitative methods of data analysis. Data was presented in form of graphs, tables and charts. The objectives of this research are therefore to identify the impacts of sand mining along River Thwake on both water quality and quantity. It also seeks to identify the social impacts of sand harvesting on the nearby society. This report describes in detail the major impacts both positive and negative of sand mining, and attempts to provide direction on how to resolve the negative impacts of sand mining. This it does through proposals and recommendations advanced later in this report