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3. TEXT CHANGES <br />Page 3-23 <br />(14) <br />Column 1, Section 3.8.6: Replace entve section. <br />3.8.6 Wetland Habitats <br />No wetlands exist on the project site itself; however, <br />wetlands are found on those portions of Yellow and Piceance <br />creeks (Map 3-2) potentially affected by groundwater <br />pumping. Since groundwater analysis has demonstrated that <br />the relative effect of groundwater pumping on Piceance <br />Creek would be negligible (Section 4.4.1, Surface Water <br />Quantity), wetlands associated with Piceaoce Creek have <br />been dropped from further discussion. <br />The potentially affected portion of Yellow Creek (lower <br />12.9 miles) currently supports an estimated 126.5 acres of <br />palustrine wetland comprised of four general classes <br />(Cowardin et al. 1979). These statistics, gathered in late <br />1986, are probably no[ representativt: of average conditions. <br />[ate summer rainfall recorded for upper Yellow Creek (Rio <br />Blanco Oil Shale Company data) during 1984-1986, was <br />nearly triple (2.7z) that received during the same period <br />(July-September) in 1978-1980, and 25 percent higher than <br />1981-1983. The vast majority of inchanoel wetlands are <br />confined to a deeply incised (l5 to 35-Foot deep) gully and <br />are subject to the influences of actively eroding vertical <br />cutbanks, alkaline sail and water conditions, highly variable <br />annual and seasonal Bows, and extensive scouring effected <br />by ice action and periodic Flooding. Welland classification <br />and acreage breakdown are provided in Table 3~A. <br />Persistent emergent wetlands appear as a herbaceous mne <br />occupying an average 10.6-foot wide fringe on either side <br />of the streambed or oxbow beds. This zone is composed <br />of two normally distinct vegetation groups. Obligate species <br />(plants usually found only in wet artas) form dense growth <br />immediately adjacent to the streamb~, and are represented <br />by sedges, meadow foxtail, inland saltgrass, and bulrush. <br />A second group of primarily facultative species (plants found <br />in both upland and wetland sites) !normally form a band <br />above the obligate zone, consisting of saltgrass, wheatgrass, <br />basin wildrye, and foxtail. ShrubJscrub wetlands typically <br />form the transition between herbaceous wetland and upland <br />vegetation. Dominants include black greasewood, rubber <br />rabbitbrush, big sagebrush, and tamarisk. This type is often <br />poorly differentiated from adjacent uplands, being <br />recognizable as a wetland type only by understory <br />composition. Tamarisk appears sparingly throughout [he <br />Yellow Creek channel, but forms a dominant overstory in <br />a consolidated I 1 /4-mile stretch below Barc~u Creek. <br />Yellow Creek's streambed, averaging 7 to 8 feet in width, <br />is predominantly a shale gravel substrate with mud or sand <br />inclusions. The unconsolidated shore class represents channel <br />braids, scour banks, and bars, which are usually gravelly <br />and sparsely vegetated with annual fortis. <br />Off channel wetlands are limited to a 42.8-acre meadow <br />on the alluvial terrace which historically was irtigated <br />hayland. This area is composed of subirrigated facultative <br />herbaceous sod shrub species, and a small (5.8-acre) Swale <br />which supports sedge and foxtail growth. <br />Aquatic Flora is sparse. Semiaquatic Ranunculus <br />(buttercups) and algae occasionally occupy an extremely <br />narrow interface between the wetted perimeter and shore. <br />A single species of pondweed occurs in small, sparsely <br />distributed colonies on submerged cobble or racks. Small <br />buoyant mats of brookgrass and watercress are found <br />occasionally where inchannel springs or seeps emerge. <br />Yellow Creek has never supported a fisheries. Aquatic <br />fauna consists almost exclusively of Diptera larvae (flies <br />in the Chirooomid and Simulid families) and Oligiochaetes <br />(annelid worms). These macroinvertebrate populations are <br />characteristic of alkaline environments subject to frequent <br />perturbation. Investigators have attributed low diversity <br />values to unstable substrates, the erosional nature of the <br />drainage, and high salt content; variable, but often rich <br />productivity figures (up to 7,000 Diptera larvae per square <br />meter) to the species adaptive response to rapidly Fluctuating <br />environmental conditions (Pennak 1974, Cathedral Bluffs <br />Shale Oil Company 1980). <br />A newly constructed beaver dam (1986), 2 miles upstream <br />from the White River, is the only visual evidence of beaver <br />activity in Yellow Creek. Constructed of tamarisk, the dam <br />is currently nonfunctional and may be abandoned-stream <br />flow having skirted the structure laterally into a vertical <br />mud bank. This beaver's appearance is almost certainly <br />related to increased Bows in Yellow Creek generated by <br />high precipitation over the past 3 years. We fcel functional <br />beaver activity a severely constrained in this drainage due <br />to lack of suitable building materials and nutritious forage, <br />the erosive properties of the channel, extreme Bow <br />fluctuations inherent to the system, and perhaps the chemical <br />properties of the water itself (e.g., mucous membrane or <br />dermal irritant). <br />Page 3-24 <br />(15) <br />See reprinted Table 3-5. <br />3-Il <br />