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Water does not exist in isolation. It is an integral part of any ecosystem and as such, every major change to this ecosystem has hydrological impacts which then lead to sociological, economic and other environmental consequences. The world’s freshwater resources are under threat from a wide variety of factors. Many of them such as over-abstraction of water from rivers and aquifers, pollution from point and non-point sources, changing patterns of precipitation are popularly known, debated and discussed widely. However, there are other crucial factors with significant social, environmental and economic impacts that are less known. One such threat is an activity known as ‘sand mining’ also referred to as dredging or gravel mining. and mining has several negative impacts.
It poses a threat to water security in several ways. Dredging results in lowering of the alluvial water table which, in turn, directly affects groundwater storage capacity (See Kondolf et al., 2001). Excessive dredging allows for saline intrusion into groundwater (Viswanathan, 2002). The lowered water table implies a rise in water costs, thus restricting access to only those who can afford it (Hoering, 2008). It results in habitat loss including destruction and fragmentation of fragile, endangered ecosystems and reduced species richness (See Myers, 1999, Global Witness, 2010).Sand mining also causes increased shoreline erosion rates, especially when mined unscientifically (Byrnes et al., 2000) and decreases protection from sea water especially during ocean disasters (Myers, 1999). It also poses a threat to critical infrastructure such as bridges, roads, railway tracks (Kondolf et al., 2001). Sand mining has also been known to cause loss of livelihoods in several instances (See Hoering, 2008, Young and Griffith, 2009 and Viswanathan, 2002). Other macroeconomic impacts have also been observed such as changes in land use patterns (Myers 1999) and increased public health costs (Myers & Muhajir I997, Mensah, 1997).
The demand for sand is fuelled by numerous factors. It appears that sand has long been commoditized and is now entrenched in global trade. Table 1 below illustrates the high trade value of this commodity. Despite the high value of this trade, or perhaps because of it, the activity is surprisingly depoliticized except when there are public concerns in specific areas...
