OCR Text |
Show The proposed drainage system would not create additional salt from irrigated land but would merely change the route by which it reached the natural surface drainage. Some lands with heavy clay soils have been abandoned because of water logging and concentrated salt accumulations. Where excessive salts exist on Unit lands proposed to be drained, the salts would be leached out as the drains began operating. This would result in a temporary increase in the salt concentrations of the area runoff. As the ground water levels and soil conditions stabilized, the salt contribution should return within a short time to pre- Unit conditions. In order to maintain the best possible quality of all drainage waters, local health ordinances would be enforced to assure that no raw sewage effluent or barnyard drainage entered the drains. The environmental impacts of construction and operation of about 157 miles of closed drains, 68 miles of open drain, 12 miles of outlet collector drains and 8 miles of natural channel improvements would be mainly associated with water quality of return flows, the lowering of water tables and resulting change in vegetative capacity of the land, temporary disruption of the landscape during construction, and creation of new bird and animal habitat along open drains. The most obvious inpacts would be the changes occurring in land use patterns as soil moisture conditions were improved. Aquatic and phreatophyte plants would be replaced by agriculturally- valuable vegetation. Bureau of Indian Affairs Activity The features concerning the Bureau of Indian Affairs activity are: ( 1) Bottle Hollow Reservoir, ( 2) Lower Stillwater Reservoir, and ( 3) development of wildlife management areas on Ute tribal lands. The reservoirs are proposed to mitigate economic losses to the Indians that would result from reducing the flow in Rock Greek. Bottle Hollow Reservoir has been completed and some of its impacts are discussed earlier in this section. The economic and social impacts are covered in later paragraphs. 275 |