WSP03721 - Laserfiche WebLink

Home Browse Search

!"I ;,:'.... f: ~'I :',. ~.< " , ,',,,. f~ .;;,:J "i ~~:-- ~~ <'1 i':l ~.;~ ~:~1 U t~ ~.4 f{'l j .~.:.:l ~;~ '<:>o~1 P.:.'-~, .', ...... ii.'-' 1(..4 f~-~! f:~:! ~:.~~ ';.A :;';;;.c ~-""-" .':'~ """J .",;..... ,.", '" ~>-.q bl ~~ 0~' ;&;1 ., CHAPTER I I PIAN FORMULATIOO land. The Smith Fork Project encompasses a major portion of the SSA. The area was selected for study because of the degraded outflow water quality and the knowledge that nearly all irrigation water is imported into the basin, and is therefore quantifiable. The majority of irrigation supplies are imported from the Smith Fork River via the Needle Rock, Crawford Clipper, and Grand view Ditches. All ditches are privately owned and operated except for the Aspen canal which is a feature of the Smith Fork project. Crawford Reservoir on Iron Creek stores Smith Fork diversions to provide supplemental water when natural river flows are depleted in late summer. In addition to providing irrigation deliveries these ditch systems also provide stockwater to area farms and ranches during the nonirrigation season. Therefore, this subarea was analyzed as a candidate for irrigation delivery system lining and winter water replacement. Grand view Mesa is an undulating plateau which slopes to the northwest and is cut by small drainage channels. The soils are largely formed from residual Dakota Sandstone weathered in place. Depths range from 2 to more than 5 feet with textures ranging from clay to clay loam. The reddish-brown mesa topsoil varies from 1 to l2 inches in depth and is underlain by a pale brown, highly calcareous subsoil. Some residual Mancos Shale overlies the Dakota Sandstone to the north near the outlets of Alum and an unnamed gulch. Land in the Cottonwood Creek drainage is generally quite broken with irrigable area located on terraces adjacent to the stream. Predominant soils include residual and recent alluvial soils derived from decomposed shale. The residual soils are heavy textured clay and are of relatively poor quality. More recent alluvial soils are weathered from Mesa verde and Wasatch formations and are of higher quality. Smith Fork Project soils generally have been well leached. The average total soluble salt content reported in 1959 was 0.1 percent with salts uniformly distributed over the profile. Of the 24,950 acres classified, less than 2 percent were rejected because of total soluble salt content above 0.5 percent. The average pH of the project land was 7.8 and no land was rejected because of alkalinity content. The principal salts reported in the Smi th Fork Project area were the sulfates and chlorides of sodium, calcium, and magnesium. The Grand view and Crawford Clipper ditch systems deliver water to approximately 78 percent of the irrigated acreage within the SSA. The Needle Rock system is composed of systems on the east and west sides of Cottonwood Creek. All of these systems are capable of direct diversion from the Smith Fork River. The Al and A2 are two small ditch systems that divert water from the lower reach of Alum Gulch. The Aspen canal supplies supplemental water from Crawford Reservoir. The above described delivery systems were field inventoried to determine canal and lateral lengths, diversion capacities, and the amount of lands served. Tables 3 and 4 present the results of this field inventory. 11 000937