2008-11-26_PERMIT FILE - M2008080 (3)

Home Browse Search

Kersey Gravel Wetland Delineation Report Ecological Resource Consultants, Inc. FAC = facultative vegetation-equally occurs in non-wetlands as wetlands General Adjacent Uplands Uplands within the Study Area are primarily disturbed, resulting from agricultural activities and animal grazing. A dirt access road exists along a ridge on the west side of the Study Area, generally defining the Study Area boundary. Two other access roads exist to provide access to the active agricultural ditches on the north side of the Study Area and the oil well in the central portion. Uplands within the Study Area are primarily vegetated by western wheatgrass, salt grass, sweet clover and kochia. These areas are generally characterized by having dry soils. Additionally, a dominance of wetland vegetation was not present within areas identified as upland. Common vegetation identified throughout the uplands is listed in Table 3. Table 3. Identified Upland Vegetation Scientific Name Common Name R g. 5 Indicator Status* A o ron smithii western wheat grass FACU Kochia sco aria kochia FACU Pol anum s p. knotweed FAC Scir us americanus three-square OBL S artina s p. salt ass FACW Sis mbrium altissimum tall tumble mustard FACU Tri olium s p. clover FACU OBL = obligate wetland vegetation-occurs an estimated 99% in wetlands FACW = facultative wetland vegetation-occurs an estimated 67%-99% in wetlands FAC = facultative vegetation-equally occurs in non-wetlands as wetlands 6.0 Conclusions ERC conducted a delineation of wetlands and irrigation ditches within the Study Area located in Weld County, CO on April 28, 2008 with a follow-up evaluation on June 9, 2008. Two irrigation ditches, the North Branch and South Branch of Plumb Ditch, were identified within the Study Area. ERC also delineated two areas (Wetland A and Wetland B) exhibiting the characteristics of a wetland. A summary of the areas investigated during the site visit is provided as follows. Irrigation Ditches The North Branch of Plumb Ditch flows east along the northern boundary of the Study Area. The South Branch of Plumb Ditch flows east through the northern third of the Study Area, approximately 500 feet south of the North Branch. Both branches are manmade, active irrigation ditches that are regulated to release irrigation water seasonally through a headgate located on the South Platte River. The ditches are excavated wholly in and draining only uplands and do not carry a permanent or relatively permanent flow of naturally occurring water. The ditches do not intercept or convey other tributary flows and would cease to exist without the dedication of irrigation water rights. Wetlands Wetland A is located in the northern third of the Study Area. The wetland is depressional and hydrologically isolated from the North Branch and South Branch of Plumb Ditch. The wetland is immediately bordered to the north and south by dirt access roads which sit several feet higher topographically than the wetland. There is no observed connection to a wetland on the east side of CR 51. The wetland appears to be completely dependent on seepage from the nearby irrigation ditches. The area meets all of the characteristics defining a wetland. 9 115