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Notes on Characteristics Identif"ied in Assessment Worksheet
<br /> 1. Consider channel flow with respect to channel cross-sectional area(expected flow),drainage area,recent precipitation,potential
<br /> drought conditions,surrounding land use,possible water withdrawals,presence of impoundments upstream,vegetation growth in
<br /> C11a1111e1 bottOm(as indicator of intermittent flow),etC.
<br /> 2. Human-caused alterations may include relocation,channelization,excavation,riprap,gabions,culverts,levees,berms,spoil piles
<br /> adjacentto channel,etc.
<br /> 3. The riparian zone is the area of vegetated land along each side of a stream or river that includes,but is not limited to,the
<br /> floodplain. Evaluation should consider width of riparian area with respect to floodplain width,vegetation densiry,maturity of
<br /> canopy and understory,species variety,presence of undesirable invasive species(exotics), breaks(utility corridors,roads,etc.),
<br /> presence of drainage tiles,logging activities,other disturbances which negatively affect function of the riparian zone.
<br /> 4. Evidence of nutrient or chemical discharges includes pipes,ditches,and direct draining from commercial and industrial sites,
<br /> agricultural fields,pastures,golf courses,swimming pools,roads,parking lots,etc. Sewage,chlorine,or other foul odors,
<br /> discolored water,suds,excessive algal growth may also provide evidence of discharge.
<br /> 5. Groundwater discharge may be indicated by persistent pools and saturated soils during dry weather conditions,presence of
<br /> adjacent wetlands,seeps,and springs feeding channel,reduced soils in channel bottom.
<br /> 6. Presence of floodplains may be determined by topography and the slope of the land adjacent to the stream,terracing,the extent of
<br /> development within the floodplain,FEMA designation if known,etc.
<br /> 7. Indicators of floodplain access include sediment deposits,wrack lines,drainage patterns in floodplain,local stream gauge data,
<br /> testimony of local residents,entrenchment ratio,etc. Note that indicators may relic and not a result of regular flooding.
<br /> 8. Wetland areas should be evaluated according to their location,size,qualiry,and adjacency relative to the stream channel, and
<br /> may be indicated by beaver activity,impounded or regularly saturated areas near the stream,previous delineations,National
<br /> Wetland InventOry maps,etC. (Wetlands must meet criteria outlined in 1987 delineation manual and are subject to USACE approval.)
<br /> 9. Channel sinuosity should be evaluated with respect to the channel size and drainage area,valley slope,topography,etc.
<br /> 10. To evaluate sediment deposition within the channel consider water turbidity,depth of sediment deposits forming at point bars and
<br /> in pools,evidence of eroding banks or other sediment sources within watershed(construction sites,ineffective erosion controls). In
<br /> rare cases,typically downstream of culverts or dams,a sediment deficit may exist and should be considered in scoring.
<br /> ll. When looking at C11a1111e1 substrate,faCtor in parent material(presence of larger particles in soil horizons adjacent to the stream),average
<br /> size of substrate(bedrock,clay/silt,sand,gravel,cobble,boulder,etc.),and diversity of particle slze(riprap is excluded).
<br /> 12. Indications of channel incision and deepening may include a v-shaped channel bottom,collapsing banks,evidence of recent
<br /> development and increased impervious surface area resulting in greater runoff in the watershed.
<br /> 13. Evaluation should consider presence of major bank failures along the entire reach under evaluation,including uprooted trees on
<br /> banks,banks falling into channel, formation of islands in channel as they widen,exposed soil, active zones of erosion,etc.
<br /> 14. Increased root depth and density result in greater bank stability. Consider the depth and density that roots penetrate the bank
<br /> relative to the amount of exposed soil on the bank and the normal water elevation.
<br /> 15. Assessment of agriculture,livestock,and/or timber production impacts should address areas of stream bank destabilization,
<br /> evidence of livestock in or crossing stream,loss of riparian zone to pasture or agricultural fields,evidence of sediment or high
<br /> nutrient levels entering streams,drainage ditches entering streams,loss of riparian zone due to logging,etc.
<br /> 16. Riffle-pool steps can be identified by a series of alternating pools and riffles. Abundance,frequency, and relative depth of riffles
<br /> and pools should be considered with respect to topography(steepness of terrain)and local geology(type of substrate).
<br /> Coastal plain streams should be evaluated far the presence of ripple-pool sequences.Ripples are bed forms found in sand bed
<br /> streams with little or no gravel that form under low shear stress conditions,whereas,dunes and antidunes form under moderate
<br /> and high shear stresses,respectively. Dunes are the most common bed forms found in sand bed streams.
<br /> 17. Habitat complexity is an overall evaluation of the variery and extent of in-stream and riparian habitat. Types of habitat to look
<br /> for include rocks/cobble,sticks and leafpacks,snags and logs in the stream,root mats,undercut banks,overhanging vegetation,
<br /> pool and riffle complexes,wetland pockets adjacent to channel,etc.
<br /> 18. Evaluation should consider the shading effect that riparian vegetation will provide to the stream during the growing season. Full
<br /> sun should be considered worst case,while good canopy coverage with some light penetration is best case.
<br /> 19. Stream embeddedness refers to the extent that sediment that has filled in gaps and openings around the rocks and cobble in the
<br /> streambed. The overall size of the average particle in the streambed should be considered(smaller rocks will have smaller gaps).
<br /> 20. Evaluation should be based on evidence of stream invertebrates gathered from multiple habitats. Scores should reflect
<br /> abundanCe,t�a riChness,arld Sensltivlty Of Strealn lnvertebrate types. (see attached examples of common stream invertebrates on page
<br /> 4).
<br /> 21. Evaluation should include evidence of amphibians in stream channeL Tadpoles and frogs should receive minimum value,while
<br /> salamanders,newts,etc.may be assigned higher value.
<br /> 22. Evaluation of fish should consider the frequency and,if possible,the variety of different fish taxa observed.
<br /> 23. EvaluatiOn Of w11d11fe Should 1nClude direCt ObservahOn Or evldenCe(tracks,shells,droppings,burrows or dens,hunting stands,evidence
<br /> of fishing,etc.)of any animals using the streambed or riparian zone,to include snall and large mammals,rodents,birds,reptiles,
<br /> insects,etc.
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