2008-11-24_PERMIT FILE - C1996083 (18)

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Dove Gulch Hydrology Renort Gault Group Inc • 1.0 Introduction Gault Group, Inc. (GGI) was retained to document and evaluate the hydrologic nature of Dove Gulch. Dove Gulch is a small tributary drainage of Hubbard Creek, a perennial stream located approximately 7 miles north east of Paonia, Colorado within the Grand Mesa, Uncompahgre and Gunnison National Forests (Figure 1). Dove Gulch is an east/west trending drainage whose confluence with Hubbard Creek is approximately three miles upstream from the Hubbard Creek/Gunnison River confluence. Dove Gulch drains east into Hubbard Creek. The purpose of the Dove Gulch investigation was to determine and document the drainage flow regime. A flow regime may be defined as either ephemeral (lasting a short period of time) or perennial (present at all seasons of the year). Dove Gulch is indicated on maps prepared by the United States Geological Survey (USGS) and GMUG as a perennial stream. The perennial status of Dove Gulch was brought into question as a result of reports from contractors conducting field work in the area. 2.0 Study Design The investigation of the stream characteristics of Dove Gulch was conducted on August 02, 2005. The investigation design provided for a pedestrian survey of the entire reach of the Dove Gulch drainage. The drainage bottom was mapped, measured, and characterized at non-random intervals ranging from 1000 to 100 feet. The sample points along these intervals were used to characterize and record the flow characteristic of Dove Gulch (Figure 2). At each sample point, channel width measurements, photos, and positional information were collected. A non-random approach was utilized in the designation of sample points to allow the recordation of the precise location of any changes in Dove Gulch hydrology. The field investigation began by vehicular access to the headwaters of the Dove Gulch drainage. From the uppermost point in the headwaters, the drainage was traversed down-canyon to its confluence with Hubbard Creek. Sample points were established at various points along the entire length of the drainage. At each sample point, detailed photos were taken in both upstream and downstream views. GPS locations were taken at each point, along with dimensions of surface water channel(s), when encountered. The point at which the any surface flow disappeared was recorded and photographed. In addition, observable changes in vegetation species were noted and recorded in order to identify any correlation with the presence of surface water. Distinct upland species were prevalent in the portion of the drainage between the lower extent of the surface water and the Dove Gulch/Hubbard Creek confluence. With the disappearance of surface water, the vegetation changed from riparian species such as aspen, narrow leaf cottonwood, to shrub species of primarily oak brush and service berry. Page 2 of 3