Effects of Silt on Ecosystems Behind Hydroelectric Dams
How does deposited silt in a reservoir affect the ecosystem?
Silt contains nutrients that become trapped behind a reservoir. The silt absorbs sunlight, warming the water and decreasing dissolved oxygen. Ecosystems downstream are starved of nutrients while the reservoir supports large algal blooms.
Silt creates habitats behind the reservoir for breeding fish. This can deplete oxygen supplies.
Deposited silt behind a reservoir can clog pipes and reduce visibility for divers.
A lack of deposited silt is actually one of the major problems with dams. Reservoirs behind dams have little substrate for fish and aquatic insects.
Silt can create small islands behind the reservoir. These can encourage a more biodiverse ecosystem upstream from dams.