Destructive mining along river banks and river beds causes a complete structural change to rivers. Dredging causes river bank erosion, silting, changes in seasonal water levels (including unnatural flooding), and changes to the river’s course.
The discharge of toxic wastes, heavy metals, and engine oil from mining operations is a serious threat not only to flora and fauna but also to humankind. Dumping mining tailings into rivers and streams is not uncommon.
When toxins like mercury become more concentrated as they pass up the food chain, they become more dangerous to humans and can affect more than one generation. The impacts of mining operations in remote eastern Shan State have yet to be fully assessed, but villagers report that water pollution has affected food crops and health there.
The decrease in healthy habitats and permanent breeding grounds due to pollution and structural changes to rivers cause a decrease in the populations of fish and water creatures. Run-off from gold mining operations in Kachin State is a series threat to the already endangered Irrawaddy dolphin.
The accumulation of mercury upstream of dams is of particular concern. As water sits behind a dam in a reservoir, bacteria transform any mercury in the water into methylmercury, a central nervous system toxin. When the water is released, it sends this toxin downstream. Toxic releases are of particular concern with dams nearby mining sites, such as the Irrawaddy/N’Mai/Mali dams, the Yeywa dam, and Shweli dams.
Although the Ministry of Mines grants concessions to mining companies and takes in revenue from mining operations, there is no enforcement of Burma’s limited laws on mining and river protection. Language in Burma’s river law prohibiting the discharge of toxins into waterways rings hollow as rivers continue to be polluted.
Information taken from the reports At What Price?, Valley of Darkness (Englisih | Burmese), Undercurrents and Robbing the future (English| Burmese)