The water stored in the reservoir is generally free from silt.
The flood inflow is generally muddy and heavily charged with silt.
Thus during floods there are two waters having different densities present is the reservoir.
Heavily silt charged water flows along the bottom of the channel towards the dam under the influence of gravity.
This current of heavily silt charged water flowing along the bottom of the reservoir towards the dam is know Density current.
If the density currents, are directly discharg out of the reservoir by suitably positioning and operating the sluice gates, the rate of reservoir silting can be considerably reduced.
