Full Pool
Reviewed • Standard Hydrology Definition • WaterLakeLevel
# Full Pool
Full pool (often called normal pool or conservation pool top) is the official target water elevation designated by dam engineers for normal water storage. When a reservoir is at full pool, all water storage capacity allocated for municipal drinking supplies, agricultural irrigation, and recreational boating is 100% satisfied.
A common misconception among recreational boaters is that full pool represents the physical crest of the dam. In reality, modern dams are constructed with substantial vertical clearance (freeboard) above full pool:
1. Conservation Storage: The active water stored beneath full pool for human consumption and boating.
2. Flood Storage (Flood Pool): The empty vertical space above full pool reserved to capture catastrophic storm runoff.
3. Emergency Spillway Crest: The concrete elevation where water begins spilling uncontrollably over the dam structure.
When a lake sits at full pool:
- Boat ramps are typically submerged to their designed optimal launching depth.
- Docks sit level with shoreline walkways and boat lifts have maximum clearance.
- Submerged hazards like tree stumps and shallow shoals have adequate water overhead.
If a reservoir rises above full pool during heavy rainfall, operating agencies may close boat ramps due to flooded parking lots and floating debris.
The designated maximum target elevation of a reservoir during standard conservation storage operations.
What Is Full Pool?
Full pool (often called normal pool or conservation pool top) is the official target water elevation designated by dam engineers for normal water storage. When a reservoir is at full pool, all water storage capacity allocated for municipal drinking supplies, agricultural irrigation, and recreational boating is 100% satisfied.
Why Full Pool Is Not the Top of the Dam
A common misconception among recreational boaters is that full pool represents the physical crest of the dam. In reality, modern dams are constructed with substantial vertical clearance (freeboard) above full pool:
1. Conservation Storage: The active water stored beneath full pool for human consumption and boating.
2. Flood Storage (Flood Pool): The empty vertical space above full pool reserved to capture catastrophic storm runoff.
3. Emergency Spillway Crest: The concrete elevation where water begins spilling uncontrollably over the dam structure.
How Full Pool Affects Boating and Docks
When a lake sits at full pool:
- Boat ramps are typically submerged to their designed optimal launching depth.
- Docks sit level with shoreline walkways and boat lifts have maximum clearance.
- Submerged hazards like tree stumps and shallow shoals have adequate water overhead.
If a reservoir rises above full pool during heavy rainfall, operating agencies may close boat ramps due to flooded parking lots and floating debris.
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.