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<br />" <br /> <br />. <br /> <br />o <br />0) <br />u' <br />(p , <br /> <br />. <br /> <br />. <br /> <br />5 <br /> <br />Four to six size classes are then "sampled" for each RAA, The physi- <br />cal and biological characteristics of such "representative reaches" are <br />established, utilizing data from the literature, records, and 7'"1i-minute <br />quadrangle topographic maps, or from a very limited amount of field <br />data collection -- if no other information is available. Such data are <br />examined to arrive at the following for each simulated reach: <br /> <br />(1) The cross-sectional shape and area of both the pools and <br />riffles in a reach, <br /> <br />(2) The proportion of pools to riffles in that size reach, <br /> <br />(3) The monthly hydrograph -- the mean and/or median monthly <br />discharges for that strata of streams, from historical records <br />or the period of record under regulated flow conditions. <br /> <br />(4) The monthly mean water temperature, and if available, month- <br />ly mean air temperatures, together with monthly max.-min. <br />air and water temperatures. <br /> <br />(5) The mean monthly sediment discharge of the stream. <br /> <br />Tarqet Species <br /> <br />The list of "target species" developed for this project includes those <br />which are expected to respond significantly to imposed physical changes <br />in their aquatic environment. <br /> <br />For each RAA, several target species are suggested. For each repre- <br />sentative stream reach, "pool species" and "riffle species" are listed for <br />evaluation of the impacts on both types of habitat. Species combina- <br />tions are listed for both small streams (i.e., smallmouth bass and rain- <br />bow darter), and other combinations more applicable to larger rivers <br />(i,e., shovel nose sturgeon and river darter). In those areas possess- <br />ing anadromous fish, at least one anadromous species is included with <br />the resident species. <br /> <br />Life Staqes <br /> <br />Fish may be affected by changes in the stream environment during any <br />of four life history stages: egg, fry, juvenile, and adult. Additional <br />critical activities, the spawning and passage phases, are also consider- <br />ed. <br /> <br />Changes in a stream reach resulting from developing a new energy tech- <br />nology may disrupt any or all of these life stages. The principal <br />changes considered in this methodology include alterations in water <br />depth, current velocity, and temperature. <br />