thousands of years, sand and gravel have been used in the construction of roads
and buildings. Today, demand for sand and gravel continues to increase. Mining
operators, in conjunction with cognizant resource agencies, must work to ensure
that sand mining is conducted in a responsible manner.
instream sand-and-gravel mining causes the degradation of rivers. Instream
mining lowers the stream bottom, which may lead to bank erosion. Depletion of
sand in the streambed and along coastal areas causes the deepening of rivers
and estuaries, and the enlargement of river mouths and coastal inlets. It may
also lead to saline-water intrusion from the nearby sea. The effect of mining
is compounded by the effect of sea level rise. Any volume of sand exported from
streambeds and coastal areas is a loss to the system.
instream sand mining is a threat to bridges, river banks and nearby structures.
Sand mining also affects the adjoining groundwater system and the uses that
local people make of the river.
sand mining results in the destruction of aquatic and riparian habitat through
large changes in the channel morphology. Impacts include bed degradation, bed
coarsening, lowered water tables near the streambed, and channel instability.
These physical impacts cause degradation of riparian and aquatic biota and may
lead to the undermining of bridges and other structures. Continued extraction
may also cause the entire streambed to degrade to the depth of excavation.
mining generates extra vehicle traffic, which negatively impairs the
environment. Where access roads cross riparian areas, the local environment may