Freeboard — definition (Water)

Water

The difference in elevation between the maximum water surface in the reservoir and the dam crest. The vertical distance between a stated water level and the top of a dam, without camber. Thus "net freeboard," "dry freeboard," or "flood freeboard" is the vertical distance between the maximum water surface and the top of the dam. "Gross freeboard" or "total freeboard" is the vertical distance between the normal water surface and the top of the dam. That part of the "gross freeboard" attributable to the depth of flood surcharge is sometimes referred to as the "wet freeboard," but this term is not recommended as it is preferable that freeboard be stated with reference to the top of dam.

Bureau of Reclamation — Bureau of Reclamation Glossary

The vertical distance between a stated reservoir elevation and the crest of the dam. "Net freeboard", "dry freeboard", "flood freeboard", or "residual freeboard" are expressions for the vertical distance between the estimated maximum water elevation and the crest of the dam. "Gross freeboard" or "total freeboard" expressions for the vertical distance between the maximum normal water elevation and the crest of the dam.

State of Nevada, Division of Water Resources — Dam Safety - Glossary of Terms retrieved 2014-06-01

The vertical distance between the normal maximum level of the water surface in a channel, reservoir, tank, canal, etc., and the top of the sides of a levee, dam, etc., which is provided so that waves and other movements of the liquid will not overtop the confining structure.

NWS — Service Hydrologist Reference Manual Glossary of Hydrologic Terms retrieved 2014-06-01

Recreation

Fishing

Portion of the dam above spillway level to protect the dam against washout.

Alabama Wildlife and Fisheries Division — Glossary of Sportfish Ponds Management Terms

Science

Weather

In hydrologic terms, the vertical distance between the normal maximum level of the water surface in a channel, resrvoir, tank, canal, etc., and the top of the sides of a levee, dam, etc., which is provided so that waves and other movements of the liquid will not overtop the confining structure

NOAA National Weather Service — National Weather Service Glossary