NPDP Dam Dictionary

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Term AKA Definition
RA student; cs student; RA is a student working for school.asdfasdfasdf
Radial gate A pivoted crest gate, the face of which is usually a circular arc, with the center of curvature at the pivot about which the gate swings (tainter gate).
Radius A user specified distance from a center location (longitude/latitude) for purposes of conducting a radial search. Only dams located within this radius are displayed.
Raffinate ponds Liquid resulting from extractions with a solvent.
Ramp flume A flume calibrated to measure the flow of liquid in an open channel.
Ramp rate The rate of change in instantaneous output from a powerplant. The ramp rate is established to prevent undesirable effects due to rapid changes in loading or discharge.
Random earthquake In addition to earthquakes that occur on mapped faults, hazards are also presented by earthquakes not associated with known geological structures. The occurrence of these events is best viewed as a random process, hence the term random" earthquake. Based on earthquake recurrence relationships for an area estimates of source-to-site distances can be calculated for various magnitudes and probabilities of occurrence."
Range Geographic region in which a given plant or animal normally lives or grows.
Rapid A section of a river where the current is very fast moving, caused by a steep descent in the riverbed through a constriction of the main channel.
Rapid flow Also refered to as supercritical flow, rapid flow is distinguished from tranquil flow by a dimensionless number called the Froude number. If the Froude number is less than one, the flow is tranquil. If the Froude number is greater than one, the flow is rapid. If the Froude number is equal to one, the flow is critical. Surface waves can propagate only in the downstream direction. Control of rapid flow depth is always at the upstream end of the rapid flow region
Raptors Birds of prey.
Rated head Water depth for which a hydroelectric generator and turbines were designed.
Reach Any specified length of stream or conveyance. A portion of a stream or a river. The area of a canal or lateral between check structures.
Reattachment deposit Sand deposit located where downstream flow meets the channel bank at the downstream end of a recirculating zone.
Recirculation zone Area of flow composed of one or more eddies immediately below a constriction in the channel.
Recreational benefit Value of recreational activity to the recreationist usually measured in dollars above the cost of participating in the recreational activity (travel, entrance fees, etc). Used for valuing recreational resources produced through Federal projects, synonymous with the consumer surplus associated with the recreational activity.
Rectangular weir A contracted or suppressed weir with a horizontal crest, rectangular in shape, having vertical sides.
Redd The nest that a spawning female salmon digs in gravel to deposit her eggs.
Refill Material which had previously been excavated as a result of construction activities and again placed to the lines as shown on the drawings.
Refuge compatibility requirements Requirements under the Refuge Administration Act that all uses of a national wildlife refuge must be compatible with the purpose for which the refuge was established.
Regulating dam A dam impounding a reservoir from which water is released to regulate the flow in a river.
Regulating gate (operating) A gate used to regulate the rate of flow through an outlet works.
Rehabilitation The process of renovating a facility or system whose performance is failing to meet the original criteria and needs of the project.
Reimbursable Costs of constructing, operating, or maintaining a Reclamation project that are repaid to the Federal Government by some other individual, entity, or organization.
Relative density Used in construction control for cohesionless soils where the in- place density is compared to the minimum and maximum density of the soil from laboratory tests.
Reliability Probability that a device will function without failure over a specified time period or amount of usage.
Relict A species, population, etc., which is a survivor of a nearly extinct group. Any species surviving in a small local area and widely separated from closely related species.
Relief Term designating the path of least resistance through which energy from explosions can be released. This path is usually taken to a free face or surface where rock can displace and energy can be released.
Relief well See drainage well.
Remote operation Operation of mechanical features from an on-site location other than at the feature.