INTRODUCTION 



The Davis County Experimental Watershed 

 (DCEW) was established in 1930 as a USDA 

 Forest Service administered research area, 

 dedicated to the study of the causes and pre- 

 vention of erosion and floods originating from 

 mountain watersheds. The area consists of 

 18,000 acres of mountain lands, ranging in 

 elevation from 4,500 to 9,200 feet in the 

 Wasatch Range of north-central Utah. More 

 recently, considerable research has been de- 

 voted to the evaluation of vegetation influ- 

 ences on water yields (Croft and Monninger 

 1953; Tew 1969; Johnston and others 1969; 

 Johnston 1970). These studies have shown 

 that substantial reductions in soil water loss 

 can be realized, if tree and brush species are 

 removed from the sites that have deep soils. 

 The scope of these studies has been restricted 

 to small plots. Logical succession dictates that 

 these results be tested on larger areas, such as 

 entire watersheds, to provide a better evalua- 

 tion of treatments in terms of actual manage- 

 ment conditions. 



The two watersheds described in this 

 paper, the East Branch and West Branch of 

 Chicken Creek, are located in the headwaters 

 of Farmington Canyon (fig. 1). These two 

 watersheds have been completely protected 

 from both fire and livestock grazing for nearly 

 40 years. Initial study of the hydrologic re- 

 sponse of the watersheds began in 1952 and 

 continued intermittently until the present. 

 Streamflow was measured on both watersheds 

 from 1952 to 1958 using 90° "V" notch 

 weirs. Measurements of air temperature and 

 precipitation were taken from 1956 to 1959. 

 In 1962 a U.S. Weather Bureau class "A" pan 

 evaporation station was installed on each wa- 

 tershed as part of a cooperative study of evap- 

 oration rates in mountainous terrain (Peck 

 and Pfankuch 1964; Peck 1967). Although 

 discontinuous, these past records provided 

 valuable data for the present hydrologic in- 

 ventory. 



In 1965, "H" type flumes equipped with 

 heating devices were installed near the mouth 

 of each watershed (Doty and Johnston 1967). 

 A network of precipitation gages was estab- 

 lished and soil moisture measurements were 

 begim on plots in the meadow, under mature 

 aspen, and on areas clearcut of aspen, using 

 neutron measuring techniques. In succeeding 

 years, seismic, soil, and vegetation inventories 

 were completed. 



This report summarizes the data collected 

 during the pretreatment hydrologic inventory 

 of these watersheds. The information will be 

 used to prescribe a vegetation treatment and 

 to designate the areas to be treated to increase 

 water yield; the primary considerations are to 

 preserve water quality and obtain a high de- 

 gree of protection against erosion. The data 

 will also provide a measure for evaluating the 

 changes that occur as a result of treatment. 

 Finally, the report furnishes the most com- 

 plete description available of a natural catch- 

 ment in the Wasatch Mountains and thus 

 serves as valuable reference material for land 

 managers. 



General Characteristics 



The East and West Branches of Chicken 

 Creek are small, adjacent watersheds (137 and 

 217 acres, respectively). They generally have 

 northwest aspects, and lie within the 7,500- 

 to 8,400-foot elevation zone (table 1 and fig. 

 2). 



The side slopes of both watersheds are rela- 

 tively gentle and have gradients ranging from 

 12 to 45 percent. A gently sloping meadow 

 occupies the bottom of each drainage and a 

 comparatively subdued ridge forms the 

 boundary between the two drainages. These 

 landforms are considered to be relatively "old 

 surfaces" according to recent geologic papers 

 (Bell 1952). 



1 



