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001623 Table 3.2. (cont.). Chute Rapid Riffle Riffle Habitats Riffle chute Shoal/riffle Shore riffle Run Run/riffle Run Habitats Scour run Shoal/run Shore run Undercut run Shoal Habitats Sand/cobble shoal Pocket water Slackwater Habitats Slackwater Inundated Vegetation vegetation Associated Habitats Overhanging vegetation September 2000 Rapid velocity (~30 em/see) portion of channel (often near center) where gradient 210 cm/m. Channel profile often U- or V-shaped. Depth typically :>::30 em. Substrate cobble or rubble and often embedded. Rapidly flowing (>150 em/sec) water over boulder substrate; typically found in steep canyon areas. Area within channel where gradient relatively steep, water velocity moderate to rapid (60 to 120 em/sec). and water surface disturbed. Substrate usually cobble and portions of rocks may be exposed. Depths vary from <5 to 50 em, rarely greater. Same as riffle except tail of riffle tenninates in a chute (>120 em/see). gradient steeper (>5 em/m). and cobble substrate often embedded. Intermediate between shoal and riffle, consists of steep, lateral cobble bar with shallow (<15 em) and fairty rapid (>30 em/see) flowing water. Same as riffle but along shore of channel, such areas do not extend across entire channel. Typically, moderate to rapid velocity (30-90 em/see), and little or no surface disturbance. Depths usually 30-120 an but may exceed 120 em. Substrate usually sand but may be silt in slow-velocity runs and gravel or cobble in high-velocity runs. Similar to run but some surface disturbance evident. typically shallower and swifter, and substrate usually cobble or rubble. Same as run and where direction of flow cuts along or into bank. Same as shoal, except deeper (>15 em) and faster flowing (>30 em/see). with either a sand or cobble substrate. Same as run and where direction of flow parallel to bank with no obvious cutting. Same as run but with overhanging bank. often bound by rootmasses of riparian vegetation. Generally shallow (<15 em) areas with laminar flow (<30 em/see). Such areas found most often on inside bends of river meanders or at downstream ends of islands or bars. Slackwater areas with little or no flow occurring amongst boulder clusters; usually located in canyon areas. Low-velocity (0 to 20 em/see) habitat usually along inside margin of river bends, shoreline invaginations. or immediately downstream of debris piles. bars. or other in-stream features. Riparian vegetation inundated by flowing or non-flowing water; fanned when river water overflows bank. Vegetation hanging over river bank, often touching the water surface. ~ FJ 3-18 Program Evaluation Report