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III. Environmental Setting, Impacts, and Mitigations F. Vegetation and Wildlife The North Branch of the South Fork of Little Johns Creek, an improved(trapezoidal),westerly- flowing perennial drainage,divides the Brocchini property from the existing landfill. The Creek is bordered on the north by an unimproved site access road(at the top of bank) and the existing landfill, and on the south by an alfalfa field(at the top of bank). This modified drainage measures approximately 6,500 feet in length and averages 25 to 35 feet in width with a depth of approximately ten to twelve feet,2:1 earthen side slopes on the subject site(4.5 acres). As discussed in the hydrology section of this document,this drainage carries heavy flows(up to an average high water mark of approximately six feet)throughout the winter and spring,with diminished flows during the summer and fall. Vegetation within the channel is generally sparse and poorly developed. Plant species observed within vegetated portions of the channel include curly dock(Rumex crispus),sedge(Carex spp.), cocklebur(Xanthium stromarium),California waterpromrose(Ludwigia peploides),mule fat (Baccharis viminea), miner's lettuce(Claytonia perfoliata),knotweed(Polygonum sp.), rabbitsfoot grass (Polypogon monspiliensis),cattail (Typha latifolia),giant bulrush(Scirpus acutus),and few young willows(Salix spp.). Species observed on the upper banks included milk thistle, wild mustard,fiddleneck,Russian thistle,horseweed(Conyza canadensis),California sage(Artemisia californica),prickly lettuce(Lactuca serriola),field bindweed(Convolvulus arvensis),common sunflower(Helianthus annuus),Bermuda grass (Cynadon dactylon),plantain (Plantago sp.),and jimson weed.(Datura meteloides). Drainage A is an ephemeral, man-made drainage that serves to convey agricultural surface runoff from lands east of the existing landfill to the North Branch of the South Fork of Little Johns Creek. This shallow drainage averages approximately five feet in width for an on-site distance of approximately 360 feet(0.1 acre). Vegetation within the channel consists primarily of ruderal species,although an overstory of fourteen valley oaks (Quercus lobata), measuring four to twenty-four inches in diameter at breast height(dbh),occur adjacent to this drainage(see Figure III.F.1). On-Site Trees(Valley Oaks) In addition to the valley oaks occurring adjacent to Drainage A,a total of eighteen valley oaks occur on the site; six occur adjacent to the North Branch of the South Fork of Little Johns Creek, eight occur along the eastern boundary of the Brocchini property adjacent to Austin Road,two occur along the western boundary of the CYA property adjacent to Newcastle Road, and two occur along the southern boundary of the CYA property adjacent to the existing landfill access III.F.6