How to Attenuate Flood Waves in a Reservoir
Reservoirs store water to supply nearby residents and generate hydropower. A well-managed reservoir maintains a void, or space, to accept floodwaters. Release of appropriate amounts of water in a timed manner prevents flooding of downstream regions. The effectiveness of floodwater attenuation depends on the size of the reservoir and the surface area and length of the spillway, where the water is discharged.
Other People Are Reading
Instructions
-
-
1
Determine the expected amount of rainfall, snowmelt and floods that will impact the region, using past records. You can get these records from the United States Geological Survey or local water resource authorities. Consult with reservoir engineers and hydrologists to determine the amount of reservoir water storage space needed for flood attenuation. To achieve storage capacity, release water slowly from the reservoir at the end of the flood season into drainage areas, rivers, sluiceways or spillways. Many localities start releasing water from the reservoirs in autumn so that by early spring, the reservoir is able to handle spring floodwaters.
-
2
Increase the floodwater storage capacity in the reservoir by using the water for other purposes such as municipal water supply and hydropower. The storage capacity of a multipurpose reservoir can be increased by both controlled flow release into waterways and floodplains and by supplying water for other needs.
-
-
3
Before releasing water from the reservoir, obtain data for the downstream water levels of rivers and waterways from downstream water authorities or water control centers. When water levels are high, don't release water from the reservoir into downstream areas. Some localities connect a large reservoir to small ones that are only used for flood storage. Alternatively, use sluiceways, or artificial channels, connected to a reservoir to accept floodwater.
-
4
Release stored floodwater from the reservoir to maintain a healthy ecosystem downstream. Often, floods are followed by droughts. The controlled release of water after the flood season can help maintain the water temperature in rivers and benefit fish, wildlife and plants.
-
1
Tips & Warnings
Managing multiple reservoirs instead of each reservoir individually can help reduce flood damage in flood-prone areas.
Sensors, installed in downstream rivers to measure river flows, can warn upstream reservoir operators about increasing river flows. Sensors need to be connected to computers in control centers.
Attenuation of floodwaters requires collaboration between reservoir operators, environmental specialists and the people whose properties and livelihood are affected by floodwaters.
When silt accumulates in reservoirs, it impacts the water storage capacity and operation of reservoirs.
References
Resources
- Photo Credit Comstock/Comstock/Getty Images
