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<br />SITE DESCRIPTIONS I
<br />Twelve floodplain wetlands along the Green River were selected for study from 1996-
<br />1998. Six sites are located on Bureau of Land Management (BLM) land between river miles
<br />(RM) 290.0 and 268.5. Five of the BLM sites are isolated from the main channel by natural
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<br />levees and one site is a natural terrace with no levees. The other six sites are located on the '
<br />Ouray National Wildlife Refuge (ONWR) between RM 261.0 and 249.5. Four of the ONWR
<br />sites are isolated from the river by a combination of man-made and natural levees. The
<br />remaining two sites are natural terraces with no levees (Figure 2.1).
<br />During 1996, prior to any levee removal, six sites were sampled (Bonanza Bridge,
<br />Baser/Chew, Above Brennan, Johnson/J4, Leota/L10, and Below Shepard). In spring of 1997,
<br />levees were breached at Bonanza Bridge, the Stirrup and Old Charlie Diked. Eight sites were
<br />then sampled in 1997 (Bonanza Bridge, Baser/Chew, the Stirrup, Above Brennan, Johnson/J4,
<br />Leota/L10, Old Charlie Diked, and Old Charlie Wash). Below Shepard was dropped from
<br />sampling in 1997. Between the fall of 1997 and spring of 1998, levees were breached at
<br />Horseshoe Bend, Baeser Bend, Above Brennan, Johnson/J4, and Leota/L7. Eleven sites were
<br />then scheduled for sampling in 1998 (Bonanza Bridge, Horseshoe Bend, Baser/Chew, the 1
<br />Stirrup, Baeser Bend, Above Brennan, Johnson/J4, Leota/L7, Leota/L10, Old Charlie Diked, and
<br />Old Charlie Wash). All sites were subsequently sampled except Leota/1,10. This site was not
<br />sampled because flows were not high enough to inundate the site for any significant duration.
<br />The 12 sites were originally classified as either depressions (i.e., sites that retain water in
<br />the bottomland following a flood event) or terraces (i.e., sites that inundate and drain with flood
<br />events). However, not all sites functioned as classified. Bonanza Bridge and Horseshoe bend
<br />were supposed to act as terraces following levee breaching, but have continued to act as
<br />depressions. Both sites overwintered fish in 1997-1998 and Horseshoe Bend will likely ,
<br />overwinter fish in 1998-1999. For our purposes, the definition of a depression has evolved to
<br />mean any site that overwinters fish.
<br />Most levee breaches were designed to flood at 13,000 cfs as recorded at the Jensen '
<br />gauging station. Exceptions are Johnson/J4, which was designed to flood at 14,000 cfs, and
<br />Leota/L7, which was designed to flood at 15,000 cfs. Following 1997 flooding, Bonanza Bridge
<br />and the Stirrup sites partially silted in and required higher flows to flood. It is unknown at this
<br />time what the floodability level for 1999 will be for sites with breaches.
<br />The time required for each wetland to fill after flows reach the flooding level depends on
<br />the size and configuration of the connection. Various types and strategies of levee removal river
<br />connections were made. Some breaches are narrow channels which backfill slowly, while others
<br />have large portions of the levee removed that allow current to push water into the site. Each
<br />wetland floods differently and merits its own description. The following information for each
<br />site was obtained from FLO Engineering (1997) and from observations recorded by work crews
<br />while in the field. `
<br />Bonanza Bridge
<br />This site was sampled during all three years of study. It is located at RM 290 onli er le
<br />and inundates 17.2 acres at 13,000 cfs (38 acres when full). In 1996, prior to the levees ?
<br />11 ? '
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