SUMMARY 



Various descriptive and hydrologic data 

 were collected as part of the pretreatment in- 

 ventory of two small watersheds (East and 

 West Branches) in the Wasatch Range of Utah. 

 These data will help determine the type of 

 treatment imposed on the watershed, as well 

 as the extent, timing, and evaluation of treat- 

 ment effects on hydrologic response. 



The two watersheds (137 and 219 acres) 

 are representative of many small, predomi- 

 nantly aspen-covered mountain drainages in 

 the Wasatch Range. Average precipitation is 

 45 inches, which is predominantly snow, and 

 mean annual temperature is a cool 36° F. An- 

 nual streamflow closely reflects precipitation 

 and has varied from 10 to 24 inches on the 

 larger area and 6 to 13 inches on the smaller 

 area during the past 5 years. About 88 per- 

 cent of streamflow occurs during the April- 

 through-June period. 



The area is geologically complex and rock 

 material underlying the solum is deeply 

 weathered and fractured. Soils are generally 

 deep, except on the ridges, but available soil 

 moisture is largely depleted throughout the 

 depth of rooting by midsummer. Average 

 evapo transpiration from the dense aspen- 

 forb-grass community is 15 inches during the 

 growing season. 



Soils appear to be fairly stable under the 

 existing vegetative cover. Water quality is 

 quite high. The highest suspended sediment 

 measurement was 59 p. p.m. and average bed- 

 load from the two areas is only 0.07 and 1.14 

 lb. per acre per year. In addition, both bac- 

 teriological counts and the amount of dis- 

 solved solids are low. 



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