A new report by UN Environment reveals that aggregate extraction in rivers has led to pollution, flooding, lowering of water aquifers and worsening drought occurrence.
Findings of the Report
Environmental governance of global sand resources presents how shifting consumption patterns, growing populations, increasing urbanization and infrastructure development have increased demand for sand three-fold over the last two decades.
Damming and extraction have further reduced sediment delivery from rivers to many coastal areas, leading to reduced deposits in river deltas and accelerated beach erosion.
As per the report, Sand and gravel are the second largest natural resources extracted and traded by volume after water, but among the least regulated.
While 85% to 90% of global sand demand is met from quarries, and sand and gravel pits, the 10% to 15% sand extracted from rivers and sea shores is a severe concern due the environmental and social impacts.
Impact of Shifting Sand
Their extraction often results in river and coastal erosion and threats to freshwater and marine fisheries and aquatic ecosystems, instability of river banks leading to increased flooding, and lowering of ground water levels.
The report notes that China and India head the list of critical hotspots for sand extraction impacts on rivers, lakes and on coastlines.
This is in addition to other threats to river systems. Most large rivers of the world have lost between half and 95% of their natural sand and gravel delivery to oceans.
The damming of rivers for hydro-electricity production or irrigation is reducing the amount of sediment flowing downstream. This broken replenishment system exacerbates pressures on beaches already threatened by sea level rise and intensity of storm-waves induced by climate change, as well as coastal developments.
There are also indirect consequences, like loss of local livelihoods — an ironic example is that construction in tourist destinations can lead to depletion of natural sand in the area, thereby making those very places unattractive and safety risks for workers where the industry is not regulated.
