Since industrial revolution, mines and dams have become essential drivers for economic growth. The second half of twentieth century has witnessed a massive increase in mining operations and dam constructions, especially in developing countries. Although both mining and dams are of much benefit to human society and development, they have devastating impacts on the environment and people living in the vicinity. It is now well proven that large scale industrial mining and hydroelectric projects destroy ecosystems, cause pollution and impact vulnerable human communities.
Impacts of Mining and Dam Building
The major impacts of mining and dam building are:
1. Deforestation or Loss of Vegetation
Both mining and dam construction lead to large scale loss of forests and vegetation. While Industrial mining, especially open pit mining, requires clearing of large areas of forest, large dam construction leads to submergence of huge tracts of forests and vegetation.
Mining operations result in air, water and soil pollution that impacts the people living in the vicinity of mines. While air pollution is caused due to harmful gases from heavy machinery and equipment and release of toxic gases from inside the mines, water pollution is caused due to mine waste rock and tailings getting mixed with surface and underground water. Air pollution is also caused during construction period of dams when heavy machinery is in use. Dams are also one of the sources of methane gas emissions (greenhouse gas) that is released from the dead and decaying vegetation inside the reservoir.
3. Land degradation and water loss
Mining activities lead to depletion of surface and groundwater supplies as water is extensively used during the processing stage. Groundwater withdrawal can have harmful effect on streams and rivers that are many miles away from the actual mine site. Moreover, mines left open after the mining, can also lead to loss of groundwater through evaporation leaving the area barren and degraded and susceptible to desertification.
One of the most serious technical problem faced by dam industry is that of siltation, which is the increased deposition of sediments brought along by the river at the bottom of dam reservoir. The sediments gradually accumulate in the reservoir, reducing the ability of the dam to store water, the very purpose for which it was constructed. The intensity of siltation varies depending upon the sediments that a river brings along. The silt laden water also causes abrasion of turbines and other dam components thus reducing their electricity generating efficiency.
5. Ecosystem and Biodiversity
Both mining and dams result in deforestation leading to habitat loss and habitat fragmentation thus affecting the biodiversity that dwells in the affected area. Dams submerge large areas of terrestrial ecosystem where reservoirs are formed, while also impacting the aquatic ecosystem due to obstructed/ reduced water flow. Mines also impact terrestrial ecosystems due to clearing of vegetation as well as any aquatic ecosystem that are in the vicinity of the mines due to pollution.
6. Displacement of Local and Indigenous Communities
One of the biggest social problems caused due to large scale mines and dam construction is the way it impacts local and indigenous communities dwelling in those areas. More often than not, these vulnerable communities are victims of injustice as they are not rehabilitated and compensated in an appropriate manner. They have to go through much emotional upheavals as they face the task of being displaced from areas where they have resided for long periods of time. Families loss their traditional ways of livelihoods as they are shifted and have to struggle very hard to find similar living and livelihood conditions in newly displaced area
7. Health problems and Social Issues
Mining operations have huge health impacts on the people working in mines, as they are constantly exposed to toxic metals, wastes and poisonous gases emanating from the mines. In many countries, mine workers don’t have proper safety gears and work in deplorable conditions. Fatal accidents are also common in mines. The pollution caused due to mines and dams affect people living in nearby villages and towns. Dams and mines also open up remote areas to developers, road builders, loggers, farmers that accelerates deforestation further. Local people also face the problem of people migrating from other regions into the areas that can increase social instability due to issues like unemployment, increase in crimes, shortage of resources etc.