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In some situations, a good reference site may not be available in the immediate area. kI these <br />cases, streams in other watersheds or regions that have similar geomorphic and ecological fea- <br />tures can be used to gain a basic understanding of the general fluvial and ecological processes <br />that would be expected in the study reach under unaltered conditions, and can thus offer a rea- <br />sonable "surrogate" reference site. <br />C. Collect BackgNOUnd Information on the Reference Reach and Study Reach <br />Prior to using RSRA in the field, it is recommended that the user collect some basic, back- <br />ground information on the study reach (see Box 1 for specific suggestions). In a few cases, <br />information gathered ahead of time will be needed to complete a score sheet item; those cate- <br />gories marked optional will be helpful to interpreting the field scores, but are not needed to <br />assign the actual scores themselves. <br />BOX 1: BACKGROUND INFORMATION TO HELP INTERPRET SITE VISIT <br />The information listed below gives a range of data that could be useful in underst~uiding present <br />and past conditions on the sh~d~~ reach. Three hinds of background infoi7nation are needed to answer spe- <br />cific items in the Score Sheet: whether beavers were historicalh~ present in the watershed. whether the <br />stream was historicalh~ perennial, and the various species of non-native or erotic plant species that have <br />been reported or are likely to be encountered at the shid~~ reach. The other information listed here is not <br />required, but may help to elplain whys the reach scores the way it does for individual indicators. Not all of <br />the data will be available for an~~ particular reach. Possible sources of information include local land man- <br />agement agencies, state and federal soil and consen~ation services, local residents. distribution maps of <br />fish and wildlife from past suz-~%evs. etc. <br />Water Qualit~~ <br />1. (optional) Are there known sources of pollution that should be considered in the evaluation (e. g.. <br />upstream mine tailings. ~~, ater treatment facilities, or livestock feedlots and holding pens)'? <br />H~ dro/Geomorphology <br />1. (optional) Determine origin(s) of stream flo~3• for the study reach (size of watersheds, springs, etc.). <br />Is it likely to be subject to large flows or flooding events'? <br />2. (optional) Determine human alterations of flow (dams, diversions or augmentations). <br />3. (optional) Determine whether there have been alterations in the upland portions of the watershed that <br />might impact the stream (e.g.. timber harvests that might lead to increased sediment loads). <br />4. (optional) Determine the current sinuosit< of stud~~ reach. This can be defined as the ratio of the actual <br />distance or length of a channel to the straight line distance beriveen the beginning and end of the sh~d~~ <br />reach, and is best measured using aerial photographs. Such photographs may' also shoe- geomorphic <br />evidence of past meanders. ~yhich can then make it possible to determine changes in sinuosity over time. <br />Sinuosih information can also be used to place the shidv reach within various classification schemes. <br />such as the categories developed by- Rosgen (D.L. Rosgen. A Classification of Nah~ral Rivers. Catena 22 <br />(1994), pages 169-199). <br />~. (required) Indicator 7 considers historic use of the shady- reach by beavers. Use elistinQ records or <br />recollections b~ local residents to determine if beavers were ever present on the reach. <br />9 <br />