standards / manuals / guidelines for small hydro development

Rated capacityRated headRating curveReactive powerRectangular weirRegulated turbineRehabilitationRelative densityRelative humidityReleaseRelief valveReserve FlowReservoirReservoirRestricted orifice surge tankReturn-flow system (reusesystem)Revetmentbook value of the investment.That capacity which a hydro generator can deliver withoutexceeding mechanical safety factors or allowabletemperature rise for design head and design flow. Ingeneral this is also the nameplate rating.Water depth for which a hydroelectric generator andturbines were designed.A curve giving the relationship between flow and waterlevel at a given location.The portion of power that is produced by load inductancesor capacitances.A contracted or suppressed weir with a horizontal crest,rectangular in shape, having vertical sides.A turbine in which the flow is controlled by a flow controldevice, such as needle valves, adjustable guide vane(wicket gates), variable runner blades or deflection arm.The process of renovating a facility or system whoseperformance is failing to meet the original criteria andneeds of the project.Used in construction control for cohesionless soils wherethe in-place density is compared to the minimum andmaximum density of the soil from laboratory tests.The ratio of the amount of moisture in the air to themaximum amount of moisture the air could hold under thesame conditions; usually expressed as a percentage.The amount of water released after use.A valve which will allow air or fluid to escape if itspressure becomes higher than the valve setting.See compensation flow or riparian flow.A body of water impounded by a dam and in which watercan be storedAn artificial lake into which water flows and is stored forfuture use.Similar to a simple surge tank except that the inlet isthrottled to improve damping of oscillations by offeringgreater flow resistance.A system of pipelines or ditches to collect and conveysurface or subsurface runoff from an irrigated field forreuse.An embankment or wall of sandbags, earth, etc.,constructed to restrain material from being transportedaway.Reynolds Number A dimensionless parameter used in pipe frictioncalculations, and derived from pipe diameter, liquidvelocity and kinematic viscosity.Riparian flowIn the sense used in this Standard, riparian flow means theminimum flow that (by law) has to be released below adiversion dam to provide for domestic use, for protectionof the aquatic environment or to meet the licensed waterAHEC/MNRE/SHP Standards / General ­ Small Hydropower Definitions and Glossary of Terms 22