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HomeMy WebLinkAboutRS_Wetland_Report_dated_6-11-15_SapphireOnTalbot_181101_v1.pdf June 11, 2015 Alun Vick 4827 Talbot Road S. Renton, WA 98055 Re: 4827 Talbot Road Wetland Reconnaissance The Watershed Company Reference Number: 150537 Dear Alun: On June 3, 2015, I visited an area located on the Ashburn Condominiums property (Ashburn Property) directly west of your property located at 4827 Talbot Road S. in Renton, Washington. The purpose of the visit was to determine the approximate location of the mapped wetland boundary on the Ashburn Property. We understand you were given verbal permission to enter the property by the Ashburn HOA. This letter summarizes the findings of this study. The following attachments are included: • Wetland Reconnaissance Sketch • Wetland Determination Data Forms • Sewall Wetland Consulting, Inc. Report Methods Public-domain information on the subject properties was reviewed for this study. These sources include USDA Natural Resources Conservation Service Soil maps, U.S. Fish and Wildlife Service National Wetland Inventory maps, Washington Department of Fish and Wildlife interactive mapping programs (PHS on the Web), City of Renton GIS mapping website (COR Maps), and King County’s GIS mapping website (iMAP). An existing conditions report prepared for the Vick property was also reviewed as part of this study (Vick/Wright Property Existing Conditions Stream Analysis Report, Sewall Wetland Consulting, Inc., March 14, 2007) (Sewall Report). The study area was evaluated for wetlands using methodology from the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region Version 2.0 (Regional Supplement) (US Army Corps of Engineers [Corps] May 2010). Wetland presence was determined on the basis of an examination of vegetation, soils, and hydrology. Only areas meeting the criteria set forth in the Regional Supplement were determined to be wetland. Soil, vegetation, and hydrologic parameters were sampled at several locations make the determination. Data Wetland Reconnaissance Report Alun Vick June 11, 2015 Page 2 were recorded at two of these locations. Findings The study area is composed of a forested plant community dominated by black cottonwood, red alder, Oregon ash, red-osier dogwood, Himalayan blackberry, and reed canarygrass. The dominant vegetation satisfies the criteria for a hydrophytic plant community, as more than 50 percent of the dominant vegetation is composed of facultative or facultative-wetland species. However, much of the vegetation, with the exception of the larger cottonwood trees, appears to be a managed plant community. Many of the sapling trees and shrubs appear to be of similar age, and remnant irrigation piping is still present in many areas. Additionally, many of the dominant species, especially the weed species, have a wide ecological tolerance and are commonly found in both wetlands and non-wetlands alike. The soil in the study area is variable, satisfying the criteria for the hydric soil indicator Redox Dark Surface (F6) at DP-1, but not satisfying hydric soil criteria at DP-2. There was no observed wetland hydrology (ground- or surface-water) present in the study area at the time of the inspection, and no primary hydrology indicators were observed. Hydrology sampling pits were dug to approximately 30 inches below the ground surface, with no detectable soil moisture observed. DP-1 is located in the lowest point of the study area, in the former drainage feature connecting to the Vick property (see below). The study area is mapped as a wetland, per the City of Renton wetland inventory. Previously, much of the Vick property was mapped as part of the same wetland. However, the wetland designation for the Vick property was changed upon verification in the Sewall Report that the wetland was a man-made landscape pond. We understand the hydrologic input to the wetland came from a man-made drainage feature that was controlled by a water-flow control valve adjacent to Talbot Road. The flow was captured in a lined pond on the Vick property, then discharged into the mapped wetland on the Ashburn property. Following the determination that the pond on the Vick property was not a jurisdictional wetland, and the drainage feature was not a jurisdictional stream, flow into the drainage feature was permanently disconnected, and the Vick wetland subsequently dried up and was completely filled. This action appears to have had the unanticipated effect of partially or completely dewatering the Ashburn wetland, as well. The effect that discontinuing a substantial hydrologic source for the wetland mapped on the Ashburn property cannot be entirely quantified at this time of year since we are past the historically wettest portion of the growing season (typically early March). However, hydrology appears to have been substantially diminished. There was no dry-season water table below the root zone as of the June inspection, and there are no indicators of recent ponding, such as an algal mat, iron deposits, surface soil cracks, water-stained Wetland Reconnaissance Report Alun Vick June 11, 2015 Page 3 leaves, or a sparsely vegetated concave surface. The soil throughout the study area does not consistently exhibit hydric soil characteristics; the plant community is not a reliable indicator, as it is a managed community; and wetland hydrology was not observed as of the date of this study. Therefore, based on the combined evidence available, it appears that mapped wetland located on the Ashburn property just west of the Vick property no longer satisfies all three wetland criteria. Wetland hydrology indicators are often the most transitory of wetland parameters. Direct hydrology observations are often only present during the normal wet portion of the growing season and may be absent during the dry season or during drier-than-normal years. Areas that have hydrophytic vegetation and hydric soils generally also have wetland hydrology, unless the hydrologic regime has changed due to natural events or human activities. In instances, particularly during the dry season, when hydrophytic vegetation and hydric soils are present but hydrology indicators are absent, best professional judgment is used to determine wetland presence and boundaries. In some situations, it may be necessary to conduct additional inspections during the normal wet portion of the growing season to determine if wetland hydrology is present in a particular area. Disclaimer The information contained in this letter or report is based on the application of technical guidelines currently accepted as the best available science and in conjunction with the manuals and criteria outlined in the methods section. All discussions, conclusions and recommendations reflect the best professional judgment of the author(s) and are based upon information available to us at the time the study was conducted. All work was completed within the constraints of budget, scope, and timing. The findings of this report are subject to verification and agreement by the appropriate local, State and Federal regulatory authorities. No other warranty, expressed or implied, is made. Please call if you have any questions or if we can provide you with any additional information. Sincerely, Ryan Kahlo, PWS Ecologist Enclosures DP-2 DP-1 Wetland Reconnaissance Sketch 4827 Talbot Road S. and Ashburn Condominiums Prepared for Alun Vick June 10, 2015 TWC Project #150537 Legend: Former Man-made Pond (filled) (approx.) Former Piped Drainage Segment (disconnected) (approx.) Former Open-channel Drainage Feature (disconnected) (approx.) Data Point Ashburn Condominiums Property Vick Property US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version WETLAND DETERMINATION DATA FORM Western Mountains, Valleys, and Coast Supplement to the 1987 COE Wetlands Delineation Manual Project Site: 4827 Talbot Road S Sampling Date: 6/3/2015 Applicant/Owner: Ashburn Condominiums Sampling Point: DP- 1 Investigator: Kahlo, R. PWS City/County: Renton Sect., Township, Range S 31 T 23N R 05E State: WA Landform (hillslope, terrace, etc) Swale Slope (%) 5 Local relief (concave, convex, none) Concave Subregion (LRR) A Lat Long Datum Soil Map Unit Name Alderwood gravelly sandy loam, 8-15% slopes NWI classification None Are climatic/hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in remarks.) Are “Normal Circumstances” present on the site? Yes No (If needed, explain any answers in Remarks.) Are Vegetation , Soil, , or Hydrology significantly disturbed? Are Vegetation , Soil, , or Hydrology naturally problematic? SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes No Is this Sampling Point within a Wetland? Yes No Hydric Soils Present? Yes No Wetland Hydrology Present? Yes No Remarks: VEGETATION – Use scientific names of plants. Tree Stratum (Plot size 5m diam. ) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet 1. Fraxinus latifolia 70 Yes FACW Number of Dominant Species that are OBL, FACW, or FAC: 4 (A) 2. Populus balsamifera 50 Yes FAC 3. Total Number of Dominant Species Across All Strata: 5 (B) 4. = Total Cover Percent of Dominant Species that are OBL, FACW, or FAC: 80 (A/B) Sapling/Shrub Stratum (Plot size 3m diam. ) 1. Salix sitchensis 25 Yes FACW Prevalence Index Worksheet 2. Total % Cover of Multiply by 3. OBL species x 1 = 4. FACW species x 2 = 5. FAC species x 3 = = Total Cover FACU species x 4 = UPL species x 5 = Herb Stratum (Plot size 1m diam. ) Column totals (A) (B) 1. Phalaris arundinacea 15 Yes FACW 2. Prevalence Index = B / A = 3. 4. Hydrophytic Vegetation Indicators 5. X Dominance test is > 50% 6. Prevalence test is ≤ 3.0 * 7. Morphological Adaptations * (provide supporting 8. data in remarks or on a separate sheet) 9. Wetland Non-Vascular Plants * 10. Problematic Hydrophytic Vegetation * (explain) 11. = Total Cover * Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic Woody Vine Stratum (Plot size ) Hydrophytic Vegetation Present? Yes No 1. Rubus armeniacus 10 Yes FACU 2. = Total Cover % Bare Ground in Herb Stratum ______ Remarks: This is a weedy plant assemblage with wide ecological tolerance. 750 Sixth Street South Kirkland, Washington 98033 (425) 822-5242 watershedco.com DP-1 US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version SOIL Sampling Point – DP-1 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks 0-2 10YR 2/2 95 10YR 3/6 5 C M Sandy loam 5-24 2.5Y 3/3 90 10YR 4/6 10 C M Sandy loam 1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains 2Loc: PL=Pore Lining, M=Matrix Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3 Histosol (A1) Sandy Redox (S5) 2cm Muck (A10) Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2) Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Other (explain in remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) Thick Dark Surface (A12) Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) Sandy Gleyed Matrix (S4) Redox Depressions (F8) Restrictive Layer (if present): Hydric soil present? Type: ________________________________________ Yes No Depth (inches): _____________________________________ Remarks: HYDROLOGY Wetland Hydrology Indicators: Primary Indicators (minimum of one required: check all that apply): Secondary Indicators (2 or more required): Surface water (A1) Sparsely Vegetated Concave Surface (B8) Water-Stained Leaves (B9) (MLRA 1, 2, 4A & 4B) High Water Table (A2) Water-Stained Leaves (except MLRA 1, 2, 4A & 4B) (B9) Drainage Patterns (B10) Saturation (A3) Salt Crust (B11) Dry-Season Water Table (C2) Water Marks (B1) Aquatic Invertebrates (B13) Saturation Visible on Aerial Imagery (C9) Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Geomorphic Position (D2) Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Shallow Aquitard (D3) Algal Mat or Crust (B4) Presence of Reduced Iron (C4) FAC-Neutral Test (D5) Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) Raised Ant Mounds (D6) (LRR A) Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Frost-Heave Hummocks Inundation Visible on Aerial Imagery (B7) Other (explain in remarks) Field Observations Wetland Hydrology Present? Surface Water Present? Yes No Depth (in): Water Table Present? Yes No Depth (in): Yes No Saturation Present? (includes capillary fringe) Yes No Depth (in): Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Soil was completely dry to 30” below ground surface US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version WETLAND DETERMINATION DATA FORM Western Mountains, Valleys, and Coast Supplement to the 1987 COE Wetlands Delineation Manual Project Site: 4827 Talbot Road S Sampling Date: 6/3/2015 Applicant/Owner: Ashburn Condominiums Sampling Point: DP- 2 Investigator: Kahlo, R. PWS City/County: Renton Sect., Township, Range S 31 T 23N R 05E State: WA Landform (hillslope, terrace, etc) Depression Slope (%) flat Local relief (concave, convex, none) Concave Subregion (LRR) A Lat Long Datum Soil Map Unit Name Alderwood gravelly sandy loam, 8-15% slopes NWI classification None Are climatic/hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in remarks.) Are “Normal Circumstances” present on the site? Yes No (If needed, explain any answers in Remarks.) Are Vegetation , Soil, , or Hydrology significantly disturbed? Are Vegetation , Soil, , or Hydrology naturally problematic? SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes No Is this Sampling Point within a Wetland? Yes No Hydric Soils Present? Yes No Wetland Hydrology Present? Yes No Remarks: VEGETATION – Use scientific names of plants. Tree Stratum (Plot size 5m diam. ) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet 1. Populus balsamifera 20 Yes FAC Number of Dominant Species that are OBL, FACW, or FAC: 3 (A) 2. 3. Total Number of Dominant Species Across All Strata: 5 (B) 4. = Total Cover Percent of Dominant Species that are OBL, FACW, or FAC: 60 (A/B) Sapling/Shrub Stratum (Plot size 3m diam. ) 1. Fraxinus latifolia 100 Yes FACW Prevalence Index Worksheet 2. Symphoricarpos albus 5 No FACU Total % Cover of Multiply by 3. OBL species x 1 = 4. FACW species x 2 = 5. FAC species x 3 = = Total Cover FACU species x 4 = UPL species x 5 = Herb Stratum (Plot size 1m diam. ) Column totals (A) (B) 1. Galium aparine 5 Yes FACU 2. Phalaris arundinacea 10 Yes FACW Prevalence Index = B / A = 3. 4. Hydrophytic Vegetation Indicators 5. X Dominance test is > 50% 6. Prevalence test is ≤ 3.0 * 7. Morphological Adaptations * (provide supporting 8. data in remarks or on a separate sheet) 9. Wetland Non-Vascular Plants * 10. Problematic Hydrophytic Vegetation * (explain) 11. = Total Cover * Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic Woody Vine Stratum (Plot size ) Hydrophytic Vegetation Present? Yes No 1. Hedera helix 5 Yes FACU 2. Rubus armeniacus 2 No FACU = Total Cover % Bare Ground in Herb Stratum ______ Remarks: 750 Sixth Street South Kirkland, Washington 98033 (425) 822-5242 watershedco.com DP-2 US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version SOIL Sampling Point – DP-2 Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks 0-12 10YR 2/2 100 Sandy loam 12-24 10YR 3/1 98 10YR 3/6 2 C M Sandy loam 1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains 2Loc: PL=Pore Lining, M=Matrix Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3 Histosol (A1) Sandy Redox (S5) 2cm Muck (A10) Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2) Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Other (explain in remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) Thick Dark Surface (A12) Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) Sandy Gleyed Matrix (S4) Redox Depressions (F8) Restrictive Layer (if present): Hydric soil present? Type: ________________________________________ Yes No Depth (inches): _____________________________________ Remarks: HYDROLOGY Wetland Hydrology Indicators: Primary Indicators (minimum of one required: check all that apply): Secondary Indicators (2 or more required): Surface water (A1) Sparsely Vegetated Concave Surface (B8) Water-Stained Leaves (B9) (MLRA 1, 2, 4A & 4B) High Water Table (A2) Water-Stained Leaves (except MLRA 1, 2, 4A & 4B) (B9) Drainage Patterns (B10) Saturation (A3) Salt Crust (B11) Dry-Season Water Table (C2) Water Marks (B1) Aquatic Invertebrates (B13) Saturation Visible on Aerial Imagery (C9) Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Geomorphic Position (D2) Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Shallow Aquitard (D3) Algal Mat or Crust (B4) Presence of Reduced Iron (C4) FAC-Neutral Test (D5) Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) Raised Ant Mounds (D6) (LRR A) Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Frost-Heave Hummocks Inundation Visible on Aerial Imagery (B7) Other (explain in remarks) Field Observations Wetland Hydrology Present? Surface Water Present? Yes No Depth (in): Water Table Present? Yes No Depth (in): Yes No Saturation Present? (includes capillary fringe) Yes No Depth (in): Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: