1991-10-07_PERMIT FILE - M1991123 (5)

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EXHIBIT I WELD COUNTY, COLORADO, SOUTHERN PART 4—Aquolls and Aquepts, flooded. This nearly level map unit is in depressions in smooth plains and along the bottoms of natural drainageways throughout the survey area. Aquolls, which have a dark colored surface layer, make up about 55 percent of the unit. Aquepts, which have a lighter colored surface layer, make up about 25 percent. About 20 percent is soils that are well drained and soils that have sandstone or shale within 48 inches of the surface. These are deep, poorly drained soils that formed in recent alluvium. No one pedon is typical. Commonly the soils have a mottled, mildly to moderately alkaline loamy or clayey surface layer and underlying material that ex- tends to a depth of 60 inches or more. In places they have a gleyed layer in the underlying material. Most of the acreage is subject to excessive runoff. The water table is at or near the surface in spring and during the peak of the irrigation season. These soils are used for rangeland and wildlife habitat. Some small areas are irrigated pasture. The potential native vegetation is dominated by switchgrass, prairie cordgrass, saltgrass, alkali sacaton, big bluestem, indiangrass, western wheatgrass, slender wheatgrass, sedge, and rush. Cattails and bullrush grow in the swampy spots associated with these range sites. Potential production ranges from 4,000 pounds per acre in favorable years to 3,000 pounds in unfavorable years. As range condition deteriorates, the tall and mid grasses decrease, production drops, and saltgrass, sedge, and rush increase. The farming and irrigation in adjacent areas has increased the amount of salts on much of the acreage. Management of vegetation on this soil should be based on taking half and leaving half of the total annual produc- tion. Switchgrass, big bluestem, indiangrass, western wheatgrass, pubescent wheatgrass, intermediate wheat- grass, tall wheatgrass, and tall fescue are suitable for seeding. The plants selected should met the seasonal requirements of livestock. For successful seeding, a firth prepared seedbed is needed. A grass drill should be used. Seeding early in spring has proven most successful. Til- lage is needed to eliminate the undesirable vegetation. Wetland wildlife, especially waterfowl, utilize this unit. The wetland plants provide nesting and protective cover as well as some food. The nearby irrigated cropland, where wildlife obtain much of their food and find protec- tive cover, makes this unit valuable to both wetland and openland wildlife. Openland wildlife, especially pheasant, use this unit for cover and nesting. Deer find excellent cover in some areas. These valuable wildlife areas should be protected from fire and fenced to prevent encroachment and overuse by livestock. They should not be drained. Capa- bility subclass VIw; Aquolls in Salt Meadow range site, Aquepts in Wet Meadow range site.