standards / manuals / guidelines for small hydro development

ApronAquatic lifeAqueductArch damAtmospheric pressureAt-rest earth pressureAuxiliary equipmentAverage annual runoffAverage daily flowAverage energyBack pressureBackfillBackfill concreteBackflowBackwaterBackwater curveA protective layer of stone of concrete block or othermaterial, extending out from a structure on or extendingbeyond the toe on the bed of a channel, or situated at someother location in the bed of a channel, laid in order toprevent erosion.Any plants or animals which live at least part of their lifecycle in water.Elevated canal supported on bridge work crossing a watercourse or gully.A concrete or masonry dam which is curved upstream inplan so as to transmit the major part of the water load tothe abutments and to keep the dam in compression.Pressure of air enveloping the earth, averaged as 14.7 psi atsea level, or 29.92 inches of mercury as measured by astandard barometer.The value of the earth pressure when the soil mass is in itsnatural state without having been permitted to yield orwithout having been compressedAccessory equipment necessary for the operation of agenerating station.For a specified area, the average value of annual runoffamounts calculated for a selected period of record thatrepresents average hydrologic conditions.The flow of water passing a specified gauging stationaveraged over a day (24 hours).The total power generation produced by a power plantduring all of the years of its actual or simulated operationdivided by the number of years of actual or simulatedoperation.A pressure that can cause water to backflow into the watersupply when a user's water system is at a higher pressurethan the public water system.Material used in refilling excavation, or the process of suchrefilling. Material used to fill an excavated trench.Concrete used in refilling excavation in lieu of earthmaterial.A reverse flow condition, created by a difference in waterpressures, which causes water to flow back into thedistribution system.A small, generally shallow body of water with little or nocurrent of its own. Stagnant water in a small stream orinlet. Water moved backward or held back by a dam, tide,etc.The upstream longitudinal profile of the surface of water instream or an open channel from a point where such watersurface is raised above its normal level by a diversionstructure.AHEC/MNRE/SHP Standards / General ­ Small Hydropower Definitions and Glossary of Terms 2