Appendix B Wetlands Table Wetland (Map ID) HGM Class Dominant Cowardin Class1 Brief Description of Feature Wetland 1 (W1) Slope PFO Wetland 1 is located at in a slight depression at the toe of a hill slope on the southwestern edge of the PSA to the south of Wetland 2. Vegetation in this wetland consists of slough sedge (Carex obnupta OBL), Oregon ash (Fraxinus latifolia FACW), and Douglas’ spiraea (Spiraea douglasii FACW). Areas of surface ponding and saturated soils were observed within this wetland during the field investigation. Wetland 2 (W2) Flats PEM This wetland is associated with a slight depression and is located in the southwestern corner of the PSA. During soil sampling within this wetland, free water was observed in the soil test pit at 16 inches with soil saturation was at 10 inches. This wetland displays evidence of algal matting, which suggests it is periodically inundated, possibly due to flooding from the adjacent ditch (Ditch 1). Dominant vegetation consists of meadow foxtail (Alopecurus pratensis FACW) and buttercup (Ranunculus spp. FACW [estimate]). Wetland 3 (W3) Flats PEM Wetland 3 is an isolated wetland located on the western PSA boundary north of Wetland 2. This area is dominated by meadow foxtail, but also contains small amounts of Kentucky bluegrass (Poa pratensis FAC), water foxtail (Alopecurus geniculatus OBL), and curly dock (Rumex crispus FAC+). Soils sampled in this wetland exhibited hydric conditions with redoximorphic features (e.g. mottles) observed within 10 inches of the surface. Wetland 4 (W4) Flats PFO Wetland 4 is an isolated wetland located north of Wetland 3 along the western edge of the PSA and is associated with a slight topographic depression. Unlike other wetland features in the PSA, this wetland has not been recently excavated and is located behind an occupied residential lot. The wetland is dominated by Oregon ash, Douglas hawthorn (Crataegus douglasii FAC), slough sedge, vine maple (Acer circinatum FAC-), red-osier dogwood (Cornus stolonifera FACW), English ivy (Hedera helix NL), and Himalayan blackberry (Rubus discolor FACU). Evidence of surface ponding (i.e., algal matting) is apparent in this wetland feature Wetland 5 (W5) Flats PEM Wetland is an isolated wetland located in a subtle depression on the west side of SE 106th Avenue. This wetland area exhibits signs of algal matting from surface ponding and a drainage ditch runs along the northern border of the wetland. Vegetation composition consists of rushes (Juncus spp. FACW), velvetgrass (Holcus lanatus FAC), bluegrasses (Poa spp. FAC), and Oregon ash saplings. Wetland 6 (W6) Flats PEM Wetland 6 is an isolated wetland located north of Wetland 4 and northwest of Ditch 2. The vegetation in this wetland consists primarily of meadow foxtail, creeping buttercup (Ranunculus repens FACW), bluegrasses, velvetgrass, red fescue (Festuca rubra FAC+), and orchard grass (Dactylis glomerata FACU). Wetland 7 (W7) Flats PEM Wetland 7 is an isolated wetland located between two currently occupied residential lots along the west side of SE 106th Avenue. The back (western) half of the lot displays evidence of algal matting indicative of long-term surface ponding and contains creeping buttercup along the edges of the lot. The front (eastern) portion of the lot contains creeping buttercup and velvetgrass and has saturated soils at the eastern edge. Wetland 8 (W8) Flats PEM Wetland 8 is an isolated excavated depression located just south of Wetland 9. The depression was likely created during removal of a single-family residence that previously occupied the site. Primary vegetation consists of reed canarygrass, green-sheath sedge (Carex feta FACW), and rushes (Juncus spp.) Wetland 9 (W9) Flats PEM Wetland 9 is a subtle isolated excavated depression on the west side of SE 106th Avenue. The depression was likely created during removal of a single-family residence that previously occupied the site. Vegetation in this wetland consists of slough sedge and Juncus sp. This wetland also displays evidence of algal matting, indicative of long-term inundation. Wetland 10 (W10) Flats PEM Wetland 10 is an isolated wetland located on the northeast side of SE 106th Avenue. Soils sampled in this wetland displayed mottles in the upper soil horizon. The dominant vegetation in this area is meadow foxtail, dandelion, velvetgrass, creeping buttercup, sweet vernal grass, and Kentucky bluegrass. Wetland 11 (W11) Flats PEM Wetland 11 is an isolated wetland located on the east side of SE 106th Avenue and borders the western edge of tax lots on SE 108th Avenue. The southern border is defined by a large Himalayan blackberry bramble. Vegetation in this large emergent wetland area consists of Kentucky bluegrass (dominant plant species), dense sedge (Carex densa OBL), red clover (Trifolium pretense FACU), velvetgrass, and dandelion (Taraxacum officinale FACU). An Oregon white oak tree (Quercus garryana NL) occupies the northeast corner of the wetland area. A sample plot was taken in this area and revealed mottled soils in the second horizon between 4 – 10 inches and low chroma soils (10YR4/1 – Munsell notation) with mottling below 10 inches. Wetland 12 (W12) Flats PEM Wetland 12 is an isolated wetland located on the east side of SE 106th Avenue in a subtle depression that likely consists of fill material. The vegetation of this area is primarily reed canarygrass (Phalaris arundinacea), meadow foxtail, and creeping buttercup. Wetland 13 (W13) Flats PEM Wetland 13 corresponds to wetland LE-6 and LE-7 of the Adolfson Associates delineation. The vegetation in this wetland area consists of Oregon ash, red alder (Alnus rubra), reed canarygrass, creeping buttercup, and common velvetgrass. Himalayan blackberry forms part of the wetland boundary on the north side. Portions of this wetland exhibited surface ponding during the site investigation. Wetland 14 (W14) Flats PEM Wetland 14 is an isolated wetland located on what appears to be the former foundation pad for a residence that has been removed from the area. Soils within this feature possess mottling in the upper horizon (i.e., above 10 inches). The dominant vegetation species in this wetland are meadow foxtail, Kentucky bluegrass, fowl bluegrass (Poa palustris FAC), velvetgrass, and dandelion. Oregon ash was observed growing on the edge of this wetland. Wetland 15 (W15) Flats PEM Wetland 15 is an isolated wetland located just south of Wetland 14. Portions of this wetland appear to have been previously excavated. Soils sampled in this area displayed distinct mottling in the upper portion of the soil profile. The dominant vegetation species found in this wetland consists of Ranunculus spp., Kentucky and fowl bluegrass, dandelion, and weeping willow (Salix babylonica FAC+). Wetland 16 (W16) Flats PEM Wetland 16 is located on the west side of SE 108th Avenue, directly east of Wetland 13. The wetland is dominated by meadow foxtail with reed canarygrass, creeping buttercup, and velvetgrass in the lower topographic areas of the wetland. The wetland also contains some fowl bluegrass. The soils sampled at this location are hydric displaying mottling in the upper portion of the soil profile. Wetland 17 (W17) Flats PFO Wetland 17 corresponds to wetland LE-5 of the Adolfson Associates delineation. This wetland contains a forested area dominated by black cottonwood and Oregon ash trees, and an understory of Douglas’ spiraea, bentgrass (Agrostis sp.) and reed canarygrass. Wetland 18 (W18) Depressional POW Wetland 18 is an apparently isolated small pond that corresponds to wetland LE-3 of Adolfson Associates delineation. This pond is surrounded by black cottonwood and willow (Salix spp. FAC [estimate]) trees as well as Himalayan blackberry shrubs. Wetland 19 (W19) Depressional POW Wetland 19 is an apparently isolated pond slightly larger than Wetland 18, which corresponds to wetland LE-4 from the Adolfson Associates delineation. This wetland contains weeping willow trees, reed canarygrass, and bentgrass species. This pond is located next to an occupied residence. Wetland 20 (W20) Flats PEM Wetland 20 is an isolated wetland associated with an excavated lot on the west side of SE 110th Avenue. This wetland feature displays evidence of algal matting and the dominant vegetation consists of Juncus sp. and water foxtail. Wetland 21 (W21) Depressional PFO Wetland 21 is a small isolated topographic swale located northwest of Wetland 20. This wetland corresponds with wetland LE-1 of the Adolfson Associates delineation. Vegetation consists of Oregon ash trees, reed canarygrass, slough sedge, and creeping buttercup. Evidence of surface ponding was observed during the field investigation. Wetland 22 (W22) Depressional PEM Wetland 22 is an isolated wetland located east of SE 110th Avenue and east of Wetland 20. This wetland corresponds to LE-2 of the Adolfson Associates delineation. This small swale contains black cottonwood (Populus balsamifera FAC) and Oregon ash trees with reed canarygrass growing in the lower areas of the depression. Evidence of surface ponding was observed during the field investigation. Wetland 23 (W23) Flat PFO Wetland 23 is located on an alluvial terrace on the south side of Johnson Creek just west of SE 112th Avenue. Soils sampled in this riparian wetland area displayed low chroma soils with mottling in the upper portion of the soil profile. Dominant plant species in this wetland include black cottonwood, Oregon ash, slough sedge, and creeping buttercup. Wetland 24 (W24) Depressional POW Wetland 24 is an apparently isolated small pond that is located southwest of Wetland 23. The pond is approximately 2 feet deep and bordered by Himalayan blackberry and Douglas’ hawthorn. Wetland 25 (W25) Flat PEM Wetland 25 is an isolated wetland located within a small topographic depression on the eastern edge of the PSA just west of SE 112th Avenue. This wetland is dominated by reed canarygrass and also contains Himalayan blackberry on the surrounding slopes. The canopy is predominantly black cottonwood and Oregon ash. Ditch 1 (D1) N/A N/A Ditch 1 is located on the northern boundary of Wetland 2 and extends through the middle of the western portion of the wetland. This ditch is approximately 3 feet wide and extends offsite to the west and presumably discharges into Johnson Creek. At the time of the field investigation, the majority of the ditch was dry except for the western end which was holding water. Ditch 2 (D2) N/A N/A Ditch 2 is approximately 1 foot wide and situated between Wetlands 5 and 6. This ditch flows east to west but appears to completely dissipate onsite and does not connect to any other wetlands or waters. No water was observed in the ditch at the time of the field investigation. Ditch 3 (D3) N/A N/A Ditch 3 is a roadside drainage ditch approximately 18 inches wide with a gravel bottom. During the field investigation this dry ditch began to hold water which came flowing in from a source southeast of the PSA. Johnson Creek Riverine R2UB1 Johnson Creek flows 26 miles from its headwaters near the Sandy River to its confluence with the Willamette River. The creek flows east to west through a meandering channel along the northern portion of the PSA. Historical streambank stabilization and armoring efforts have led to a deeply incised channel through the PSA and at various other locations along the stream course. The depth of the creek ranges from approximately 2-8 feet and the width varies from approximately 7-13 feet within the PSA. Note: See Appendix A for location information on Wetlands and Ditches.1 Cowardin et al. 1979.R – Riverine; 2 – Lower Perennial; UB1 - Unconsolidated bottom cobble gravel. P – Palustrine; EM – Emergent; OW – Open water; FO – Forested; UB4 – Unconsolidated bottom organic; B – Saturated.