Opinion ID: 411109
Heading Depth: 3
Heading Rank: 4

Heading: Sediment

Text: 13 Generally, large reservoirs act as sediment traps; the water velocity decreases (compared to the upstream river) and sediment settles to the bottom of the reservoir. Thus, water released from the dam will contain less sediment than upstream water. This is generally viewed as an improvement in water quality. However, the river will tend to restore its equilibrium [sediment] loading by scouring the downstream channel. 14 Also, the reservoir will tend to fill with sediment, which in some cases can require periodic dredging or sluicing. Dredging may temporarily increase sediment load in the reservoir (and hence in the downstream water); sluicing is a deliberate attempt to have the river carry accumulated sediment downstream. 15 14 Sediment release can be reduced by careful dredging or by filtering. There is no evidence in the record to suggest that increased sediment is a major problem. 16