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HomeMy WebLinkAbout27,28,30,31-RS_Critical_Area_Report_VEK_on_Aberdeen_191106_v11 Century Const. Renton CAD Report August 18, 2018 Mr. Petr Marchenko 13220 42nd Ave E Tacoma WA 98446 Email: washingtonbesthomes@gmail.com Phone: 425-333-7737 RE: Critical Areas Designation (CAD) 957 Aberdeen Ave NE- Parcel #3119900066 City of Renton, Washington Dear M. Marchenko, As requested we have evaluated Parcel 3119900066 property for jurisdictional wetlands, streams, and required buffers. The CAD wetland delineation encompassed the entire site, and offsite to sight limit of the periphery of the parcel. The western portion, west of the stream, was not flagged for wetland boundary. Location and Existing Conditions The property is located west of Aberdeen Ave NE in City of Renton, WA (fig. 1). This property is rectangular, 54,057 sq. ft. [ 1.24 acre]. The site contains a single-family house in the east. Figure 1. Site Vicinity Methodology Sources: Esri, HERE, Garmin, USGS, Intermap, INCREMENT P, NRCan, Esri Japan, METI, Esri China(Hong Kong), Esri Korea, Esri (Thailand), NGCC, © OpenStreetMap contributors, and the GIS UserCommunity 2 Century Const. Renton CAD Report The site visit was conducted on June 21, 2018. A combination of field indicators, including: soils, vegetation, and hydrology, were used to determine whether wetlands were present. Onsite assessment followed the established criteria and methods as defined within the Corps of Engineers (CoE) Wetland Delineation Manual - 2010 Western Mountains, Valleys, and Coast (WMVC) Regional Supplement, Revised Washington State Wetland Rating System (WSWRS), and City of Renton Code 21A-24 Critical Areas. Wetlands are transitional areas between aquatic and upland habitats. In general terms, wetlands are lands where the extent and duration of saturation with water is the primary factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface (Cowardin et al., 1979). Wetlands are generally defined as "those areas that are inundated or saturated by surface water or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions." (City of Renton). Wetlands exhibit three (3) essential characteristics, all of which must be present for an area to meet the established criteria within the Wash. Manual and the CoE Manual. These essential characteristics are: Hydrophytic Vegetation: Meaning a predominance of plants that are typically adapted for life in saturated soils, Hydric Soil: Meaning soils that are saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper horizons, and Wetland Hydrology: Meaning permanent or periodic inundation, or soil saturation to the surface, at least seasonally. Streams are delineated by identification of the Ordinary High Water Mark (OHWM). The definition of the OHWM as defined by the Washington State Department of Ecology as a part of the Shoreline Management Act is: “the mark on all lakes, streams, and tidal water that will be found by examining the bed and banks and ascertaining where the presence and action of waters are so common and usual, and so long continued in all ordinary years, as to mark upon the soil a character distinct from that of the abutting upland, in respect to vegetation as that condition exists on June 1, 1971, as it may naturally change thereafter, or as it may change thereafter in accordance with permits issued by a local government or the department: Provided, That in any area where the ordinary high water mark cannot be found, the ordinary high water mark adjoining salt water shall be the line of mean higher high tide and the ordinary high water mark adjoining fresh water shall be the line of mean high water”. The boundary of the stream was flagged pink and labeled consecutively. Sample data points were flagged with pink and marked SP#1-2. 3 Century Const. Renton CAD Report Existing Documentation National Wetland Inventory (NWI) resources identify linear wetland (drainage) at the west boundary of the site (fig. 2). Figure 2. NWI Map – 1 in. = 500 ft. R4SBC PEM1Cx Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, © OpenStreetMap contributors, and the GIS User Community 4 Century Const. Renton CAD Report City of Renton Critical Area data identifies an unnamed tributary to Johns Creek transecting the west of the site, confluencing with Johns Creek near the west boundary of project site (fig. 3). These streams are designated Type 4 (Type Ns) Streams. Figure 3. Renton Wetland Map – 1 in. = 250 ft. Johns C reek4 Johns Creek4Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS, FAO, NPS, NRCAN,GeoBase, IGN, Kadaster NL, Ordnance Survey, Esri Japan, METI, Esri China (Hong Kong), swisstopo, © OpenStreetMap contributors, and the GIS User Community 5 Century Const. Renton CAD Report The NRCS soils map identify soils on the site as: AkF Alderwood and Kitsap soils, very steep not listed as hydric. RdC Ragnar-Indianola association, sloping not listed as hydric. RdE Ragnar-Indianola association, moderately steep not listed as hydric. WA Dept. of Fish & Wildlife Priority Habitat and Species data indicate no presence of priority habits or species on the site (attached). Field Observations The project site contains one primary upland and critical area. The eastern one-half of the parcel is on an elevated bench which contains the house and garage. West of this, the topography drops precipitously to a lower area, and then moderately slopes to the west. Upland Areas The project site contains one primary upland and wetland habitat area. Vegetation: The entire site is regrowth forest. Major plant species include alder (Alnus rubra), Douglas-fir (Pseudotsuga menziesii) and Himalayan blackberry (Rubus armeniacus). Johns C reek4 Johns Creek4Ur RdC AkF RdE InC AgC 6 Century Const. Renton CAD Report Soils: The soils throughout the project area consist of Alderwood Gravelly Sandy Loam (AgC). This soil parent material is basalt till with some volcanic ash and is moderately well drained. Soil plot data for the upland areas was 0-12 in. 10YR3/6 and 12-16 in. 10YR4/2 with no hydric soil indicators. Hydrology: Surface flow through the site is generally directed by topography from the east to west. A drainage transecting the site captures overland flow and directs it west to Johns Creek at the west boundary. Wetlands Small wetlands occur in conjunction with the streams in the west portion of the site. The stream course flows approximately through the center of the site going west, and the standard buffer boundaries include the entire western portion of the site. As they are occluded by the drainage and its buffer, they were not flagged or called out. Streams A ditch transects the site from the center of the north boundary to the west boundary, through the center of the site. This drainage originates at a detention pond on the parcel to the north, which drains through a 12 in. culvert to the head of the drainage. The drainage is deeply incised and actively eroding. This stream meets the criteria for definition as a Type Ns Water. iv. Type Ns: Waters that do not contain fish or fish habitat and have intermittent flows. These are seasonal, non-fish habitat streams in which surface flow is not present for at least some portion of a year of normal rainfall and are not located downstream from any stream reach that is a Type Np Water. Ns Waters must be physically connected by an above-ground channel system to Type S, F, or Np Waters. Type Ns waters mandate a 50 ft. buffer measured from the OHWM. Off Site No other wetlands occur within sight distance of project boundaries. Pertinent Regulation City of Renton Title IV DEVELOPMENT REGULATIONS Chapter 3 ENVIRONMENTAL REGULATIONS AND OVERLAY DISTRICTS 4-3-050 CRITICAL AREAS REGULATIONS G. DEVELOPMENT STANDARDS: 7. Streams and Lakes: a. Classification System: The following classification system is hereby adopted for the purposes of regulating Streams and Lakes in the City. This classification system is based 7 Century Const. Renton CAD Report on the State’s Permanent Water Typing System WAC 222-16-030. Stream and lake buffer widths are based on the following rating system: i. Type S: Waters inventoried as “Shorelines of the State” under chapter 90.58 RCW. These waters are regulated under Renton’s Shoreline Master Program Regulations, RMC 4-3- 090. ii. Type F: Waters that are known to be used by fish or meet the physical criteria to be potentially used by fish and that have perennial (year-round) or seasonal flows. iii. Type Np: Waters that do not contain fish or fish habitat and that have perennial (year- round) flows. Perennial stream waters do not go dry any time of a year of normal rainfall. However, for the purpose of water typing, Type Np waters include the intermittent dry portions of the perennial channel below the uppermost point of perennial flow. iv. Type Ns: Waters that do not contain fish or fish habitat and have intermittent flows. These are seasonal, non-fish habitat streams in which surface flow is not present for at least some portion of a year of normal rainfall and are not located downstream from any stream reach that is a Type Np Water. Ns Waters must be physically connected by an above- ground channel system to Type S, F, or Np Waters. b. Non-regulated: Waters that are considered “intentionally created” not regulated under this Section include irrigation ditches, grass-lined swales and canals that do not meet the criteria for Type S, F, Np, or Ns Non-regulated waters may also include streams created as mitigation. Purposeful creation must be demonstrated through documentation, photographs, statements and/or other persuasive evidence. 8 Century Const. Renton CAD Report Findings The drainage on the site meets the criteria for definition as a “stream”. However, the water source is “unnatural” in that it is derived from a stormwater system on the parcel to the north which focuses flow and forces it to the drainage course. This water is diverted from the stream to the north into the on-site drainage. The substantial erosion indicates a recent change in flow regime is altering the stream morphology. Because of these considerations, the drainage is unnatural and should not be regulated as a stream. Proposed Site Development No development scheme is determined. All development actions will respect the drainage category and buffer determined on review. If you have questions or need additional information please contact me at 253.732.6515 or by email at mheckert@q.com. Respectfully Submitted, Mark Heckert, President Att. Wetland Delineation Map WDFW PHS report