OCR Text |
Show The number of sampling stations required to adequately describe a section of stream and to maintain acceptable limits of precision depends upon the length of the section. In general, the 1- mile interval would be adequate for streams that are 15- 30 miles long with closer spacing being required on shorter streams. 103 The 1972 Forest Service Report ( Stream Habitat Studies on the Uinta and Ashley National Forests) 109 was published as part of that agency's comments on the Bonneville Unit Draft Environmental Statement. The report furnished data collected from six stations located on two streams while stating that sampling points on each stream were located at 1- mile intervals beginning at the Forest boundary and extending upstream to and including the location of the particular Unit feature under study. It also states that selected stations were permanently established on each stream so that discharge measurements at the stations could be taken annually for comparative purposes. No comparative data for different years were included. This situation for streams having recommended minimum bypasses is illustrated below: Stream Miles on Forest Below Feature127 On Forest No. of Sampling points Established127 Off Foresti 1/ No. of Sampling Station Analyses Published in the 1972 Report 109 Rock Creek 8.50 Wolf Creek 1.25 West Fork of the Duchesne River 4.50 Currant Creek 5.00 Total 19.25 11 3 5 24 4 0 2 11 1/ Data obtained cooperatively by the State and the Forest Service but is presently unavailable. 120, 133, 169 It is evident that enough sampling stations were established to meet the minimum requirements for adequate streamflow description and statistical precision but that data for only 25 percent of these stations were published. Only on Currant Creek are data from a sufficient number of stations presented. On Wolf Creek and West Fork of the Duchesne River no data are presented and the assumption is made that the original reconmendations, made in 1962, 1 77 are still valid. i^/ Discussion with the Forest Service personnel partially responsible for the 1972 report revealed that, to ensure accuracy, only data from |