Case studies of environmental impacts of sand mining and gravel extraction for urban development in Gabarone

Abstract

Economic development is one of the main objectives of developed and developing nations worldwide. Development comes with growth of urban areas. Urban growth is achieved through sand and gravel mining for construction of modern, attractive and durable structures. The study examined positive and negative environmental impacts of the continuous removal of river sand, pit sand and gravel from sampled rivers and open areas surrounding Gaborone developing Central Business District, malls and private properties in city. Quantitative and qualitative research designs that is questionnaire survey, oral interviews, field observation and measurements were used to collect data from selected sampled points. Metsimotlhabe and Ditlhakane rivers were selected because they are nearer to Gaborone and most river sand is mined from these rivers. More points were sampled from open areas in Kumakwane, Kopong and Bela Bela farms where pit sand and gravel are mined. Convenience and purposive sampling methods were used to pick questionnaire survey respondents (175) from Kumakwane and Metsimotlhabe villages where people affected lives. Findings of the study highlighted that river sand was mined most from rivers near Gaborone compared to pit sand and gravel because of its multi uses. Mining is important for economic development, to construct durable, modern structures, employment creation and revenue collection but removal of river sand leads to deepening and widening of rivers. Artificial rivulets are formed as resource is extracted uncontrollably. Pit sand and gravel are extracted from open areas creating uncovered deep pits, which caused of accidents to children and livestock. Erosion and environmental degradation occur due to continuous mining. Miners dispose waste on open areas and riverbeds causing land pollution. Dust and noise pollution from tipper trucks ferrying sand and gravel are a cause of concern to villagers as the trucks move even at night, disturbing sleep. Solutions to uncontrolled mining include 24 hour security and regular raids on illegal miners. The author recommends that heavy penalties should be imposed to curb illegal mining. High level decision making forum involving all stakeholders is necessary to discuss problems of illegal mining and how to limit negative impacts. Department of Mines need to develop an Environmental Management Plan and a close monitoring program nationwide.