Normal Pool
Reviewed • Standard Hydrology Definition • WaterLakeLevel
# Normal Pool
Normal pool refers to the authorized operating elevation of a lake under standard conditions. In reservoir engineering, the term is frequently used interchangeably with full conservation pool.
On many multi-purpose reservoirs managed by the U.S. Army Corps of Engineers or the Tennessee Valley Authority, 'normal' is not a single static elevation number. Instead, normal pool changes with the calendar month according to an official rule curve:
- Summer Normal Pool: Maintained at higher elevations (e.g. 1,071 ft) to support peak boating, marina slips, and municipal demand.
- Winter Normal Pool: Deliberately lowered by several feet (e.g. 1,065 ft) to create empty reservoir capacity for winter snowmelt and spring cloudbursts.
Always check whether a cited normal pool refers to the summer conservation level or the winter drawdown guide curve.
The typical, authorized elevation of a lake or reservoir during standard non-flood operations.
What Does Normal Pool Mean?
Normal pool refers to the authorized operating elevation of a lake under standard conditions. In reservoir engineering, the term is frequently used interchangeably with full conservation pool.
Why 'Normal' Varies by Season
On many multi-purpose reservoirs managed by the U.S. Army Corps of Engineers or the Tennessee Valley Authority, 'normal' is not a single static elevation number. Instead, normal pool changes with the calendar month according to an official rule curve:
- Summer Normal Pool: Maintained at higher elevations (e.g. 1,071 ft) to support peak boating, marina slips, and municipal demand.
- Winter Normal Pool: Deliberately lowered by several feet (e.g. 1,065 ft) to create empty reservoir capacity for winter snowmelt and spring cloudbursts.
Always check whether a cited normal pool refers to the summer conservation level or the winter drawdown guide curve.
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.