Flood Pool
Reviewed • Standard Hydrology Definition • WaterLakeLevel
# Flood Pool
A reservoir's flood pool (or flood control storage) is the vertical capacity located immediately above full conservation pool. Under standard weather conditions, this storage zone remains completely empty.
When torrential storms drop inches of rain across a river basin, dam gates are partially closed. Instead of rushing downstream and submerging populated cities, the excess runoff swells into the reservoir's flood pool.
Once the downstream river crests and recedes within its banks, dam operators slowly release the stored floodwater in a controlled manner until the lake drops back down to full conservation pool.
The temporary storage capacity above full conservation pool designed to capture floodwaters and prevent downstream damage.
What Is a Reservoir Flood Pool?
A reservoir's flood pool (or flood control storage) is the vertical capacity located immediately above full conservation pool. Under standard weather conditions, this storage zone remains completely empty.
How Dam Operators Use the Flood Pool
When torrential storms drop inches of rain across a river basin, dam gates are partially closed. Instead of rushing downstream and submerging populated cities, the excess runoff swells into the reservoir's flood pool.
Once the downstream river crests and recedes within its banks, dam operators slowly release the stored floodwater in a controlled manner until the lake drops back down to full conservation pool.
Explore Other Hydrology & Boating Terms
Acre-Foot
A volumetric water unit representing the amount of water required to cover one acre of land to a depth of one foot.
Conservation Pool
The volume of water stored in a reservoir dedicated to beneficial uses such as drinking water, power, and recreation.
Datum
A reference surface or mathematical baseline from which vertical elevations or geographic coordinates are reckoned.
Dead Pool
The critical low-water elevation below which water cannot flow downstream through gravity outlets.
Drawdown
The deliberate or natural reduction of a lake or reservoir water surface elevation.
Evaporation Loss
The invisible volumetric loss of water from a lake surface into the atmosphere caused by heat, sun, and dry winds.