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-2- Average annual precipitation within the Red Wash basin varies from 9 - 12 inches. Information in the permit application indicates that certain tributary drainages in the upper reaches of Red Wash are intermittent because ground water may enter the stream during the snowmelt season. Two stock watering ponds have been constructed in tributary drainages to the north and west of the AVF study area, but the ponds generally dry up during the summer. Red Wash, in the vicinity of the permit area, flows only for a short period in early spring due to snowmelt runoff, and in response to intense storm events during summer and fall. The SCS land use map indicates that no irrigation occurs along drainages in Rio Blanco County which are similar to Red Wash with respect to basin size, climate, soils and vegetation. Examples are Dripping Rock Drainage, Stinking Creek, Spring Creek and Fletcher Creek in western Rio Blanco County. Tributary drainages which do support irrigated agriculture are without exception characterized by higher precipitation headwater areas which support aspen, mountain brush and coniferous vegetation types. These drainages are either perennial or dependably contain flows sufficient to allow diversion during the irrigation season (Alvin Jones, personal communication). The land use map and discussion with Mr. Jones, Range L"onservationist with the Soil Conservation Service in Meeker, document that it is not the regional practice to irrigate alluvial deposits associated with ephemeral drainages contained within the 9 - 12 inch precipitation zone in Rio Blanco County. C. Salinity hazard of surface water based on data in the ERO study would be classified as "high" based on USGS criteria (USGS, 1970). D. Vegetation and soil pit information in the ERO Document indicate that greasewood (Sarcobatus vermiculatus), the most prominent veyetation species on the alluvial terraces adjacent to the Red Wash channel is probably subirrigated. Greasewood is a salt tolerant phreatophyte and soil pits indicate an alluvial zone of saturation at depths of between 5 and 8 feet. Greasewood is not an agriculturally useful species and is, in fact, poisonous to sheep under certain conditions. Data collected by the applicant do not indicate the presence of agriculturally significant vegetation which might be expected to benefit from the high water table. TViis is supported by observations made on-site by Division staff in September, 1983. The potential agricultural importance of the high water table and subirrigation is negated by the high electrical conductivity (EC) of the alluvial ground water. Analyses of yround water quality samples collected from alluvial well Qal - 2 located at the confluence of Red Wash and the White River indicate a range in EC levels from a low of 3,500 umhos/cm to a high of 12,000 umhos/cm between March, 1981 and August, 1982 (ERO, 1982). Based on a USGS irrigation water rating chart (USGS, 1970), the salinity hazard of such water would be rated "very high".