WSP11035 - Laserfiche WebLink

Home Browse Search

data, saltgrass and wiregrass photographs generally indicated that the total density of vigorous plants could be less near the well. Infrared photographs of all exclosures will be obtained in late August 1982. b. Long-term monitoring program--A long-term vegetation monitoring program will be established in Stage 1-2 initially and expanded to each Succes- sive stage as the project is constructed. This monitoring program will con- tinue during project operation to determine the overall effects of pumping on preproject vegetation, the capacity to graze domestic livestock, the value of the wildlife habitat, etc. The monitoring program for Stage 1-2 has been developed and partially established on the ground. The plant species selected and monitored in the study plots will be greasewood, rabbitbrush, saltgrass, wiregrass, and a variety of other plant species. The program will help deter- mine if project pumping will significantly affect existing plant species and, for example, the carrying capacity for grazing of domestic livestock in a given area. Data collected from the vegetation study and the analysis at that time will be available to the general public at the project office in Alamosa, Colorado. c. Revegetation program--A small-scale revegetation study was initiated in June 1982 near the long-term pump test site. Four 30- by 50-feet rectangular plots were fenced and subdivided into smaller subplots. The plots were established and seeded in a manner as to compare various treatments such as cleared versus uncleared, irrigated versus nonirrigated, distance from test well or water table depth, plant species seeded, and seeding rate. Plant species seeded for comparison include blue grama, Indian ricegrass, alkali sacaton, sand dropseed, western wheatgrass, slender wheatgrass, fourwing saltbush, and annual ryegrass. Results of the revegetation trials at the plots are not available at this time but will be available to the public when they are obtained. Several additional disturbed areas within the I-acre salvage well sites were reseeded in June with variable mixes of the above plant species. Additional I-acre sites will be reseeded in the fall season, 1982, to determine a rela- tionship between seeding dates. No results are available at this time. 2. Effects. Terrestrial vegetation and associated wildlife habitat will be affected by construction of conveyance channel and installation of salvage wells, lateral water collection systems, and access roads. Construction of the conveyance channel will disturb 1,527 acres. Another 180 acres will be disturbed by installation of the salvage wells. Where the preproject water table depths are 10 feet or more below the ground surface, lowering of the existing ground water table will not affect existing vegetation. The total acreage of terrestrial vegetation and associated wildlife habitat that will be affected due to drawdown pumping will be 11,098 acres. Grazing capacity by domestic livestock on specific lands will also be reduced over the long term because of decreased plant vigor, density, and total production. 3. Mitigation. Some 11,098 acres of land within project boundaries will experience a varying degree of reduction in plant vigor and density due to pumping drawdown. The effect on vegetation will be most severe in the immediate j r --- " ...... ,~', 1- I....I;....-l.u.:..,;"