2013-01-25_REPORT - M1992069 - Laserfiche WebLink

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2011 Annual Status Report Aggregate Industries: Greeley F Street Site January 17, 2012 estimated to be approximately one acre in size. This wetland has developed along three benches. The lowest (south) bench is now partially submerged by the higher water level in the West Side pond. Numerous plains cottonwood seedlings and saplings thrive along the "new" shoreline that have established since the flood. The upper bench is characterized by an almost solid stand of spikerush (Eleocharis macrostachya) with some woolly sedge (Carex lanuginosa) scattered throughout. Vegetation cover on the upper bench is approximately 90 to 95 percent. Twenty -four (24) wetland plant species were noted in the wetland area. This is an increase in diversity from 2007 but a drop from twenty -nine (29) wetland species in 2009. There has been an increase of one (1) wetland species since 2010. Approximately 60 percent of the species on these wetland benches have an indicator status of Facultative or wetter (Table 1). Prior to 2010, it was suspected that the Boyd - Freeman Ditch immediately to the west was supplying supporting hydrology to establishing herbaceous wetlands in the far northeast corner of this wetland. Indeed some of the existing wetland vegetation in this corner is drying, coincident with the fact that the adjacent segment of the ditch no longer conveys water since the flood. However, the rest of this wetland area continues to thrive and expand, strongly suggesting a connection to other subsurface water. Between this water source, as well as surface connection to the north shoreline of the West Side Pond, it is expected that this area will continue to expand and develop in terms of plant species diversity. Portions of Areas B and C have previously exhibited very little germination by seeded species. However, much of Area B seeded in 2009 is now submerged and a 'new' shoreline for the West Side Pond supports broad - leafed cattails, bulrush species (Schoenoplectus spp.), and a few narrow -leaf cattails (Typha angustifolia). It is expected this wetland fringe will persist even if the current water level drops, "following" the capillary fringe to wherever it eventually stabilizes. A notable number of plains cottonwood saplings have colonized this north shoreline, east of the existing wetland benches described above. These will likely persist having had two growing seasons in connection with the pond capillary fringe, which should have allowed them to establish their taproots and gain connection with subsurface water. Seeded benches in Area C were inundated in 2010 as well as for some time in 2011. However, as the high water levels receded, portions of these areas support almost no vegetation development except for small amounts of common sunflower, kochia, and a few scattered grass species. In contrast, many native upland grasses are flourishing along the upper seeded bench in Area B include dense stands of western wheatgrass (Pascopyrum smithii) and switchgrass in less alkaline areas and saltgrass in more alkaline soils. Wildlife observed in and around Areas B and C include double- crested cormorant, great egret, killdeer, Canada geese, western meadowlarks, an American white pelican, a red - tailed hawk, an American kestrel, a great blue heron, red winged blackbirds, a northern harrier. Numerous toads were observed throughout the area. Coyote scat, deer tracks, and raccoon tracks were also noted. As has been noted in previous monitoring reports, an existing band of shrubs begins in the northwest comer of Area B and extends south along the slope on the west edge of the property. This community is dominated by coyote and peach - leaved willows. Other species on the slope include plains cottonwoods, bulrushes, witchgrass (Panicum capillare), and Russian -olive (Elaeagnus angustifolia). The slope was separated from the mitigation area pond by a wide berm that has since been submerged by the flood waters. Large numbers of the shrubs that had 3 ■