The Buzi Basin encompasses three major tributaries of the Buzi, Lucite and Revue Rivers, with 88% of the catchment area located in Mozambique and 12% in Zimbabwe. The Zimbabwean side is heavily exploited for agriculture and related activities, while the mid and lower reaches of the basin in Mozambique are not as intensively utilised at present. However, several new and planned developments such as biofuels and sugar cane production will significantly change future water demand and allocation in the basin. Small-scale gold miners in the basin have been identified as the major polluter impacting surface water, groundwater and wetlands adjacent to the river. Other activities with adverse effects are agriculture, human settlements, deforestation, and river flow modification due to increased use.
Added to this are inappropriate catchment management activities in various parts of the Buzi basin such as shifting and slope cultivation, charcoal burning, and gold panning, which have led to land degradation including increased sediment loads and deteriorating water quality. The main sectors linked to the immediate causes of land degradation are agriculture and mining at commercial and subsistence levels.
Among the visible impacts of land degradation in the Buzi basin is the declining water quality as a result of nutrient enrichment from agricultural activities, pollution from gold mining activities (especially artisanal gold panning) and changes in sediment load, amongst other sources of pollution. There have also been reports of the existence of heavy metals in certain localised areas due to mining activities. At a time when the types and sources of pollution are increasing, reduced volumes of water in the river system prevent effective dilution, compounding the water quality problem. This has affected socio-economic activities such as agriculture, fishing, industry, and water supply as well as causing deterioration of ecosystems.
According to estimated population projections conducted by Mozambique’s National Institute of Statistics in 2007, the population in the Basin on the Mozambican side was expected to increase from approximately 1,368,900 in 2020 to 1,705,000 by 2030.
Women and girls bear the brunt of poor-quality water because they have to travel long distances in search of clean water for domestic and other uses. This takes up a lot of their time which could have been expended on income-generating activities. It also keeps girls away from school.