Environmental impacts of sand harvesting in Rwanda. Case study of Kajegemba wetland, Kamonyi District, Southern Province

Abstract

Nowadays, the demand for sand in Rwanda has increased tremendously as a result of rapid economic development and subsequent growth of construction sector. This, in many ways, has resulted in uncontrolled mining of sand resources wherever they occur in the country leading to severe damages to environment. The case is rather alarming in Kajegemba wetland, Kamonyi District, Southern province, Rwanda. This study was therefore carried out to investigate the environmental impacts resulting from sand harvesting in Kajegemba wetland. Data used in the present study were collected through desk review, field observations, survey, interview and laboratory analysis of water sample. The study revealed that irrespective of the large quantity of sand being mined from the wetland with its economic importance, sand mining activities in the wetland are causing much harm. Results of the field observations show that land degradation, water pollution showed by high turbidity of water, erosion, loss of vegetation and collapsing of stream banks (90 m over), are the major environmental effects that result due to sand mining in the area. 0.2 % of the wetland has been found to be degraded. Water of the streams in the wetland were highly turbid (18-21 Turb NTU) because of high sediment deposit as a result of sand mining activities. Restoration of the created pits to prevent from the spread of disease transmission vectors, water retention, erosion, land collapsing, etc. would be a remedy to the environmental problems related to sand harvesting in the area. Also, sand mining activities should be carried out in selected places not in every corner of the wetland. Sand mining activities should be carried out in controlled and organized way to ensure that the environment is protected.