|
annual discharge as measured at the Colorado - Nebraska state line occurs in these three
<br />months. Flows during the fall, winter, and early spring months (October through April)
<br />increase somewhat over summer flows and are fairly uniform. Each month, these flows
<br />contribute approximately 7% to the South Platte River's total annual discharge as
<br />measured at the Colorado - Nebraska state line. This uniform flow is an attribute of the
<br />return flows from the alluvial groundwater aquifer.
<br />VEGETATION
<br />Native plant communities occurring on the TRSWA and PESWA include, open and closed
<br />cottonwood stands, mixed willow- cottonwood stands, willow stands, wetlands, salt
<br />meadows, and short to mid grass prairie communities. In addition to native plants, the
<br />CDOW has introduced and cultivated many exotic plant species for wildlife management
<br />purposes. These plants include, American plum, Russian olive, eastern red cedar, rocky
<br />mountain juniper, and various row crop plants like corn, millet, sorghum, and sunflowers.
<br />These non - native species have been planted mainly on the TRSWA on historically farmed
<br />lands. The native plant community along these flood plains is typically SO to 90 percent
<br />grasses, 5 to 10 percent forbs and 5 to 10 percent shrubs. Alkali sacaton is the dominant
<br />plant in the potential plant community. Switchgrass, western wheatgrass, prairie
<br />cordgrass, inland saltgrass, alkali bluegrass, Baltic rush, and Nebraska sedge are
<br />prominent species. Canada wildrye, little bluestem, slender wheatgrass, big bluestem,
<br />various sedges and rushes, American licorice and fourwing saltbush are present in small
<br />amounts. Cottonwoods and willows of the river bottom form bordering plant communities
<br />and occasionally a cottonwood or willow may be seen in this plant community.
<br />Short to mid grass prairie communities border the flood plain in areas dominated by sand y
<br />types of soil. The plant community is about 75 to 90 percent grasses, 5 to 15 percent forbs,
<br />and 5 to 10 percent shrubs. Sand bluestem, prairie sandreed, yellow Indiangrass and
<br />switchgrass are the dominate species. Needle- and - thread, blue grama, Bessey sandcherry,
<br />and sand sagebrush are secondary plants. Little bluestem, hairy grama, thickspike
<br />wheatgrass, western wheatgrass, sand dropseed, tall dropseed, prairie junegrass, red
<br />threeawn, sand paspalum, sandhill muhly, Indian ricegrass, Schweintitz flatsedge sun
<br />sedge, bottlebrush squirreltail, bush morningglory, spreading eriogonum, stickleaf
<br />mentzelia, prairie spiderwort, Nuttal evolvulus, lemon scurfpea, and snowball sandverbena
<br />are also present in small amounts. No trees are native to the short to mid grass prairie
<br />communities of these sites. Several parcels within this community have been inter- seeded
<br />with switchgrass on the TRSWA. A list of potentially occurring native plant species for the
<br />project area can be found in Appendix B.
<br />FISH AND WILDLIFE
<br />Warmwater riverine habitats like those found on the TRSWA and PESWA are
<br />characterized by highly fluctuating, and turbid flows -- characteristics which favor native
<br />
|