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<br />~- <br /> <br />Glucgrasses (I'oa spp.) <br />Grome grasses (Gromus spl'.) <br />Rushes (Juncus spp.). <br /> <br />TIle Dolores River Instream Flow Assessment reported that, further downstream, box elder is often <br />present in habitat niches seemingly more suitable for cottonwoods. <br /> <br />Although some mature cottonwoods occur adjacent to the active channel, the denser overs tory forests generally <br />occur in old overflow channels and oxbows. These areas have become separated from the river by channel down <br />cutting and low flow conditions. The mature trees are now dependent on groundwater for survival, not direct <br />Ooodillg from'the river. <br /> <br />. Young stands of cottonwood saplings and seedlings are infrequent along this portion of the Dolores <br />River. Regeneration of cottonwood is primarily dependent on high spring flows. Since the dam was completed <br />in 1984, it has regulated the natural peak flows during the spring. Spill management releases of 4,500-5,000 cfs <br />have occurred since 1984. Regulated flows in a river downstream from a dam typically do not allow the <br />frequency of overbank flooding needed to provide recruitment (reproduction) of the dominant riparian plant <br />species, such as cottonwood (Brinson 1981, Asplund 1988 and Scott 1993). <br /> <br />RIPARIAN SHRUBLAND <br /> <br />Riparian shrub dominated communities become increasingly common downstream of McPhee Dam, and <br />become the dominant riparian community below Disapoinonem Creek. Also, the invasion of salt cedar (Tamarix <br />ramosissima) is evident along the Dolores River downstream from the confluence of Disappoinnnent Creek. are <br />not COlIllllon and occur sporadically in narrow belts. along the river banks. These shrub communities are <br />generally dominated by a sparse to dense cover of coyote willow (Salix exilrua). They can also include other <br />shrubs, such as desert olive and gambel oak (Ouercus eambelii). The understory is generally sparse and <br />composed of a variety of grasses and forbs. <br /> <br />EMERGENT W<:TLAND <br /> <br />Emergent wetland areas are not common in the project area. No extensive marshes, such as cattail <br />(Tvoha spp.) or bulIrush (Sclrous spp.) dominated communities, have been identified along the Dolores River <br />from McPhee Dam to Bradfield Bridge. However, some small communities dominated by wetland grasses, <br />spikerushes (Eleocharis spp.) and rushes (Juncus spp.) can occur in small depressions and backwaters. <br /> <br />LONE DOME RECREATION AREA WETLAND <br /> <br />A major feature of the Lone Dome Recreation Area (described later in this chapter) is a cooperative <br />effort by Reclamation and CDOW to create, preserve and enhance wetlands down slope of Lone Dome Ditch. It <br />is located approximately seven miles downstream from McPhee Dam. This area was historically irrigated for <br />pasture, but has not been farmed in many years, The CDOW has acquired 1,000 acres of land in the area. They <br />have also acquired water rights totalling 4.5 cfs. The CDOW has replaced the original diversion structure and <br />reconstructed the canal and ditch. This will provide water to S4 acreS of existing wetlands as well as the creation <br />of 24 acr" of new wetlands. <br /> <br />LAND USE IMPACTS TO EXISTING WETLAND/RIPARIAN VEGETATION COMMUNITIES <br /> <br />Existing weiland and riparian communities along the Dolores River have been affected by livestock <br />r,razing and trailing for many years. Grazing was discontinued by the OLM and the USFS along the Dolores <br />River from McPhee Dam to approximately four miles upstream of Slick Rock in thc late 1980's. Downstream to <br /> <br />29 <br />