2008-02-22_APPLICATION CORRESPONDENCE - C2008086 (42)

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Table 1. Wetland Area Summary Wetland Type Area Area in Flag Numbers Upland/V1letland Transects ID acres and comments Wetland Fringe Q 0.38 Q001-Q014 TPU - TPW, between flags (Total area = 3.12 acres R 1.09 R001-R039 P008 & L009. S 0.49 S001-S032 T 0.03 T001-T008 U 0.11 0001-U047 Mack Wash V 0.035 V001-V024 Gov. Highline Canal De-Watered TLU- TLW, between flags Wetland Marsh L 1.45 L001-L019 L018 & L019 total area = 1.45 acres Dry areas within J J001-J008 Within polygon H Wetlands Emergent Wetland Marsh Polygons H, K, M, and O are located on a terrace east of East Salt Creek. This complex consists of one large emergent wetland marsh (H) (Photos 19 & 20), and three smaller emergent wetland marshes, polygons K, M, & O (Figure 3). These polygons receive irrigation return flow from elevated agricultural lands and a tree farm east of 10 Road. Excess water in spring and summer months provides a surface water connection to East Salt Creek. Irrigation return flows appear to be augmented by groundwater that sustains hydrology when irrigation flows stop. Surface water connections that were observed with East Salt Creek were associated with irrigation return flows. Plant species in these wetlands include: cattail (Typha latifolia), three-square (Scirpus puragens), and alkaligrass (Puccinellia spp.). Polygon A is located 1.6 miles south of polygon H on the same terrace. It is located below an agricultural field, Photo 18 and Figure 4, and its primary source of hydrology is irrigation return flows from that field. During irrigation season the area establishes periodic surface water connections with Mack Wash and groundwater seepage maintains hydrology during the growing season. Vegetation in polygon A is dominated by cattails and some common spikerush. Soils for all polygons on the terrace are mapped as Persayo silty clay loam. Polygons A, H, K, M, and O had hydric soil indictors categorized as F3, Depleted Matrix, which is characterized by 60 percent or more chroma of 2 or less and meets thickness requirements established by NRCS. Soils in polygon A also showed gleying. Wetland Fringe Polygons B, C, D, E, F, G, S, and T receive water from an irrigation ditch that passes underneath the railroad tracks near delineation flag B-6. Water at polygon B is impounded and transferred through a culvert into polygon C (Photos 2-4). Polygons E and D are associated with a subsurface connection from impounded water in Polygon B (Figure 5). Polygon C also impounds water and conveys it down an irrigation ditch to the west. This ditch is elevated 2 to 4 WestWater Engineering Page 4 of 75 January 2008 DBMS 425