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elevation at "ach monument (concrete base with brass cap) is in- scribed on the top and may be used for establishing water surface elevations directly in the field. Railroad and highway structurus w~re field surveyed for the study by Gingery Associates STUDY AREA DESCRIPTION Drainage Basin Characteristics The study area on Beaver Creek near Brush, Colorado, is lo- cated in Morgan County, approximately 90 miles northeast of Denver. Beaver Creek drains approximately 1,089 square miles within parts of Morgan County, Washington County, Adams County, Arapahoe County, Lincoln County and Elbert County, to the downstream study limit at Interstate 76. The headwaters of Beaver Creek are located ap- proximately 80 miles upstream of Interstate 76 near Interstate 70, northwest of Limon, Colorado. The creek flows in a northerly di- rection to the South Platte River, approximately 4-1/2 ~iles down- stream of Interstate 76. Tpe drainage area ranges in elevation from approximately 6,000 feet above sea level in tho basin head- waters to elevatio:'l 4,216 at the down!<tream study limits and ~1~vati0n 4,lS0 at the South Platte River. The limits of the Beaver Creek drainage area arc shown on the Basin Map, Plate 1. The reach of Beaver Creck considered in this study includes the reaeh from Interstate 76 south, approxi~ately 4 miles, to thA section line between Sections 13 ",nd 24, Township 3 North, Range 56 West. The limits of the detailed study are shown on the Index Map, Plate 2. The Badger Creek dralnage, direccly west of the B.."veL Cl."",J.,. drainage area, was also analyzed as a part of this study. The Badger Creek drainage is a long and narrow basin draining approxi- mately 277 square miles. This basin has its headwaters in Arapahoe County ,lnci drains through ^dams County and Morgan County. This basin WaS analy~ed as a part of the flood plain information report I , 1 I. -5- completed on Beaver Creek because of the potential for floodwaters to spill from the Badger Creek basin into the Beaver Creek basin, at ooints near the Burlington & Northern railroad tracks and State Highway 6-.14. The normal annual precipitation in the Beaver Creek and BrUSh area is approximately 1.1 inches per year. Included as part of the precipitation is snowfall of 26 inches per year. The mean annual temperature in the Brush area is 48.9 degrees ranging from a nor- mal average temperature of 74 degrees in July. Vegetation in the basin consists of farmland crops in the lower reaches and prarie grasses in the upper reaches. The pre- dominant soils in the basin consist of sand and sandy loam soils and, to a lesser extent, silt loam and some clay loam. Study Reach Description The study reach is centered extends four miles upstream from Plate 2, shows the study limits. The normal low flow channel for Beaver Creek meanders through the study roach traversing approximately 7.4 miles through the 4-mile reach of flood plain. The topography adjoining Beaver Creek is very (lat to the west but quite steep to the east. Through the study reach, six major rn~dq and railroad~ cro~s th8 creek. Two of these facilities, the Burlington Northern railroad directly east of town and County Road DLD, one-half mile south of lown, significantly affect flood ~lows within the flood plain. In addition to the road and railroad crossings within the east of the City of Interstate 76. The Brush Index "od Map, flood plain, the City of Brush is located in the flood plain area. The road and railroad embankments as well as the buildings and streets in town serve as obstructions to the orderly passage at flood flows through this portion of Beaver Creek. Through the study reach, the main channel is s~all, inadequate and restricted by the n~tural vegetation, limitinq the effectiveness of the channel. The prim;:;.ry obstructions to flood flows through the study area are the brush ~nG vegetation qrowi~q along an~ wlthin the -6-