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HomeMy WebLinkAboutRS_Stream_Critical_Area_Habitat_Data_20170421_v1Rick Tomkins, PE 03/20/2017 Page 2 Figure 1 Project Location METHODS Streams and their ordinary high water mark (OHWM) are defined by both the U.S. Corps of Engineers (Corps) and Ecology. The Corps (2014) guidance defines the OHWM as “that line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.” Ecology’s guidance (Olson and Stockdale 2010) defines the OHWM for state waters. The following physical characteristics were used to identify the OHWM as defined by the Corps (2005):  Natural line impressed on the bank  Shelving changes in the character of soil  Destruction of terrestrial vegetation  Presence of litter and debris wracking  Vegetation matted down, bent, or absent  Sediment sorting  Leaf litter disturbed or washed away Project Study Area Rick Tomkins, PE 03/20/2017 Page 3  Scour  Deposition  Multiple observed flow events  Bed and banks  Water staining  Change in plant community Ditches may also be considered jurisdictional when they transport relatively permanent flow (continuous flow for at least three months) directly or indirectly into waters of the United States. All ditches within the study area were reviewed to determine if they meet the Environmental Protection Agency (EPA) and Corps guidance (EPA and Corps 2008) for being jurisdictional waters. In most situations, it was not possible to document whether a ditch or channel within the study project area has relatively permanent flows. The presence of an OHWM should be used as a baseline to establish the potential of relatively permanent flows. The OHWM and relatively permanent flow can be indicated by the following physical characteristics:  Presence of a defined channel with bed and bank  Areas exhibiting scour marks  Debris wracks  Shelving  Water staining  Areas of flowing or standing water  Clear areas of gravel with no vegetation REGULATORY ANALYSIS The City of Renton Critical Areas Regulations are established in the Renton Municipal Code (RMC) 4-3-050. The City defines streams, stream classification, buffers, and alterations to these features as follows: RMC 4-3-050 section 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 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. Rick Tomkins, PE 03/20/2017 Page 4 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. c. Measurement: i. Stream/Lake Boundary: The boundary of a stream or lake shall be considered to be its ordinary high water mark (OHWM). The OHWM shall be flagged in the field by a qualified consultant when any study is required pursuant to this subsection G7. ii. Buffer: The boundary of a buffer shall extend beyond the boundaries of the stream or lake to the width applicable to the stream/lake class as noted in subsection G2 of this Section, Critical Area Buffers and Structure Setbacks from Buffers. Where streams enter or exit pipes, the buffer in this subsection shall be measured perpendicular to the OHWM from the end of the pipe along the open channel section of the stream. d. Stream/Lake Buffer Width Requirements: i. Buffers and Setbacks: (a) Minimum Stream/Lake Buffer Widths: See subsection G2 of this Section. (b) Piped or Culverted Streams: (1) Building structures over a natural stream located in an underground pipe or culvert except as may be granted by a variance in RMC 4-9-250 are prohibited. Transportation or utility crossings or other alterations pursuant to subsection J of this Section are allowed. Pavement over a pre-existing piped stream is allowed. Relocation of the piped stream system around structures is allowed. If structure locations are proposed to be changed or the piped stream is being relocated around buildings, a hydrologic and hydraulic analysis of existing piped stream systems will be required for any development project site that contains a piped Rick Tomkins, PE 03/20/2017 Page 5 stream to ensure it is sized to convey the one hundred (100) year runoff level from the total upstream tributary area based on future land use conditions. (2) No buffers are required along segments of piped or culverted streams. The City shall require easements and setbacks from pipes or culverts consistent with stormwater requirements in RMC 4-6-030 and the adopted drainage manual. ii. Increased Buffer Width: (a) Areas of High Blow-down Potential: Where the stream/lake buffer is in an area of high blow-down potential for trees as identified by a qualified professional, the buffer width may be expanded an additional fifty feet (50') on the windward side. (b) Habitat Corridors: Where the stream/lake buffer is adjacent to high functioning critical areas (e.g., wetlands, other streams, other identified habitats), the stream/lake buffer width shall be extended to the buffer boundary of the other protected critical area to establish a habitat corridor as needed to protect or establish contiguous vegetated areas between streams/lakes and other critical areas. e. Criteria for Permit Approval – Type F, Np, and Ns: Permit approval for projects on or near regulated Type F, Np and Ns water bodies shall be granted only if the approval is consistent with the provisions of this subsection, and complies with one of the following conditions: i. A proposed action meets the standard provisions of this Section and results in no net loss of regulated riparian area or shoreline ecological function in the drainage basin where the site is located; or ii. A proposed action meets alternative administrative standards pursuant to this Section and the proposed activity results in no net loss of regulated riparian area or shoreline ecological function in the drainage basin where the site is located; or iii. A variance process is successfully completed and the proposed activity results in no net loss of regulated riparian area or shoreline ecological function in the drainage basin where the site is located. RESULTS One stream (Rolling Hills Creek) was identified in the study area. Stream location is shown in Figure 2. No ditches were identified on the property. Rick Tomkins, PE 03/20/2017 Page 6 Figure 2 Stream Location From the City of Renton GIS Rick Tomkins, PE 03/20/2017 Page 7 ROLLING HILLS CREEK Rolling Hills Creek runs along the southern property boundary. The creek flows from a culvert 250 feet to the east along the property and enters one of two culverts 50 feet west of the project study area. Downstream, a 48-inch stormwater culvert conveys lower flows to the west and then to the south. A second, large 12-foot culvert flows southwest. Both of these culverts are mapped by the City as ultimately discharging at the same location farther to the southwest. The stream culverts convey flow to a large wetland complex south of I-405 and east of SR-167, and then flow to Springbrook Creek which flows to the Green River. Rolling Hills Creek receives flow from the hill slope to the southeast of the study area and includes flow from Thunder Hills Creek. The confluence of Rolling Hills Creek and Thunder Hills Creek occurs in the culvert system to the east of the property study area. Within the property, the creek has been channelized along the existing development. The channel width is from 7 to 9 feet wide and the bank full width is from 12 to 13 feet wide. The bank full width was delineated and surveyed in the field. The stream bank is eroded with vertical to overhanging slopes 2 feet high. The stream bed through the study area is primarily gravel, sand, and fines with some cobble and areas of rip rap. There is little woody debris in the stream. There is trash and abandoned house hold items in both the stream and buffer areas. The stream buffer to the south extends to the right of way and structural wall for I-405. This buffer is 30 to 45 feet wide with trees, shrubs, and emergent vegetation. Buffer to the north extends to the existing parking lots on the property. This buffer area is 7 to 21 feet wide and includes some trees and emergent vegetation and little shrub vegetation. Rolling Hills Creek is not documented on Washington State Department of Natural Resources (WDNR) or Washington State Department of Fish and Wildlife (WDFW) online databases. There are documented salmon in Springbrook Creek downstream of the study area and Rolling Hills Creek. The City of Renton identifies the stream as a Type Np (non-fishbearing perennial) stream (Figure 3). A Type Np stream as defined by WAC 222-16-030 and RMC 4-3-050 is afforded a standard buffer width of 75 feet. Ordinary High Water Mark (OHWM) for Rolling Hills Creek The OHWM was delineated, flagged in the field, and the location was surveyed. A general map of the project site, existing conditions, and the OHWM is shown in Figure 3. Cross sections of the stream showing existing conditions and the proposed building conditions are shown in Figure 4. Rick Tomkins, PE 03/20/2017 Page 8 Figure 3 OHWM for Rolling Hills Creek in the project study area. Rick Tomkins, PE 03/20/2017 Page 9 Figure 4 Cross section of the study area and Rolling Hills Creek. Rick Tomkins, PE 03/20/2017 Page 10 WILDLIFE AND WILDLIFE HABITAT Habitat in the study area is limited to Rolling Hills Creek and its buffer. The study area is bordered on the south by I-405 and on the north by existing parking for the Roxy Cinema. This narrow corridor of habitat that is entirely surrounded by development. Trees along Rolling Hills Creek include: black cottonwood (Populus balsamifera), willow (Salix spp.), red alder (Alnus rubra), and Lombardy popular (Populus nigra). The understory includes both native western swordfern (Polystichum munitum) and salal (Gaultheria shallon) and invasive species including: Himalayan blackberry (Rubus armeniacus), reed canarygrass (Phalaris arundinacea), English ivy (Hedera helix), and English holly (Ilex aquifolium). Endangered Species Act (ESA) listed species, proposed species, critical habitat, or essential fish habitat (EFH) under the jurisdiction of the National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS) that are recorded as potentially occurring in the project study area are listed in Table 1. The Washington Department of Natural Resources and Washington Department of Fish and Wildlife do not document rare plants, animals, or habitats within the study area or within a one-mile radius (WDFW 2017a, WDFW 2017b, WDNR 2017a. and WDNR 2017b). No suitable habitat for these species exists in the action area; therefore, the project would have no effect on the species. Table 1: USFWS and NMFS Listed Species and Critical Habitat in Snohomish County # Common Name Scientific Name Federal Status Jurisdiction 1. Bull trout Salvelinus confluentus Threatened USFWS 2. Marbled murrelet Brachyramphus marmoratus Threatened USFWS 3. Yellow-billed cuckoo Coccyzus americanus Threatened USFWS 4. Streaked horned lark Eremophila alpestris strigata Threatened USFWS 5. North American wolverine Gulo luscus Proposed Threatened USFWS Bull Trout and other salmonid species are not documented in Rolling Hills Creek nor are not documented in Spring Brook Creek. The neared record of bull trout is in the Green River (WDFW 2017a). If bull trout were present, they would not utilize Rolling Hills Creek due to the high levels of disturbance and poor habitat quality. The Green River, which represents the closest potential habitat for bull trout, is over three mile downstream of the project area. Therefore, the project will have no effect on bull trout. The marbled murrelet nests in old growth or mature forest stands, usually located within 50 miles of saltwater. The action area contains no suitable nesting habitat, does not support marine foraging habitat, and is not located in a major movement pathway (WDFW 2012). Therefore, the project would have no effect on marbled murrelets. The yellow-billed cuckoo is considered extirpated in Washington, with no known extant breeding population, and no documented occurrences in the action area (WDFW 2012; WDFW 2017b). Only a handful of sightings have been documented in Washington in the last few decades (SAS 2015). Therefore, the project would have no effect on yellow-billed cuckoo. The streaked horned lark is closely associated with the glacial outwash prairies of south Puget Sound and the outer coast (WDFW 2012), and has no potentially suitable habitat or documented Rick Tomkins, PE 03/20/2017 Page 11 occurrences in the project area (WDFW 2017b). Therefore, the project would have no effect on streaked horned lark. The North American wolverine occurs rarely in high-elevation alpine portions of Washington (WDFW 2012). The project site is well outside potential range of this species; therefore, the project would have no effect on North American wolverine. FLOODPLAINS Portions of the subject property are mapped as 100-year floodplain (Renton 2017). The location of the100-year floodplain is shown in Figure 5 below. Impacts The proposed project will have no direct impacts to Rolling Hills Creek. There will be no net loss of buffer along Rolling Hills Creek over existing conditions. The existing parking lot edge will remain unchanged. No culverts associated with the creek will be modified. Modifications to the stormwater system will be minimal. There will be some re-routing of storm water due to the new building footprint. The existing system will remain and there will be no changes to the existing points of discharge. Stormwater in the existing drainage system is first routed through an existing oil-water separator. As part of the proposed project work, additional treatment for the impacted pavement areas will be provided. The likely treatment facility will be a “Modular Wetland” filter vault. This improved treatment would have a beneficial effect on water quality in Rolling Hills Creek. RESTORATION Restoration of the riparian habitat along Rolling Hills Creek may be included in the project design. If restoration occurs, it will likely include the following actions: 1. Removing litter and artificial debris throughout the buffer. 2. Remove invasive plants (including Himalayan blackberry, reed canarygrass, English ivy, and English holly) in the buffer. 3. Plant native shrubs and groundcovers to protect slope and compete with invasive species. Native species that would deter access by people and pets can be used on the north side of the creek. 4. Install fencing to keep people and pets out of the stream and buffer. 5. Install signs designating the buffer and stream as protected areas. Rick Tomkins, PE 03/20/2017 Page 12 Figure 5 One Hundred Year floodplain and Floodway Boundary. Rick Tomkins, PE 03/20/2017 Page 13 REFERENCES Environmental Protection Agency and U.S. Army Corps of Engineers. 2008. Memorandum on Clean Water Act Jurisdiction Following the U.S. Supreme Court’s Decision in Rapanos v. United States & Carabell v. United States. Olson, P. and E. Stockdale. 2010. Determining the Ordinary High Water Mark on Streams in Washington State. Second Review Draft. Washington State Department of Ecology, Shorelands & Environmental Assistance Program, Lacey, Washington. Ecology Publication # 08-06-001. Renton, 2017. COR Maps. Accessed on March 16, 2017. Available at http://rentonwa.gov/government/default.aspx?id=29886 Seattle Audubon Society. 2015. BirdWeb – Yellow-billed cuckoo. Available at http://birdweb.org/birdweb/bird/yellow-billed_cuckoo. U.S. Army Corps of Engineers (Corps). 2005. Ordinary High Water Mark Identification. Regulatory Guidance Letter No. 05-05. The U.S. Army Corps of Engineers, Washington DC Washington Department of Fish and Wildlife (WDFW). 2012. Threatened and Endangered Wildlife in Washington: 2012 Annual Report. Listing and Recovery Section, Wildlife Program, Washington Department of Fish and Wildlife, Olympia. 251 pp. ———. 2017a. Salmonscape Fish Distribution Map. Accessed on March 16, 2017. Available at http://fortress.wa.gov/dfw/gispublic/apps/salmonscape/default.htm. ———. 2017b. Priority Habitats and Species (PHS) Online Mapper. Viewed on March 16, 2017. Available at http://wdfw.wa.gov/mapping/phs/. Washington State Department of Natural Resources (WDNR). 2017a. WDNR Natural Heritage Program GIS data. Dated September 18, 2014. ——. 2017b. Forest Practices Water Type Maps. Accessed on March 16, 2017. Available at http://fortress.wa.gov/dnr/app1/fpars/viewer.htm. Enclosures: Photographs VIA 405 Apartments Enclosure Date 2017 Stream Memo Site Photographs Page 1 Creek outlet into the 12-foot and 48-inch culverts approximately 50 feet down stream of property boundary February 2, 2017 Creek approximately 50 feet up stream of property boundary February 2, 2017 VIA 405 Apartments Enclosure Date 2017 Stream Memo Site Photographs Page 2 Creek in center of property showing up creek right bank view and existing buffer February 2, 2017 Creek in center of property showing up creek left bank view and existing buffer February 2, 2017 VIA 405 Apartments Enclosure Date 2017 Stream Memo Site Photographs Page 3 Creek in center of property showing down creek left bank view and existing buffer February 2, 2017 Creek in center of property showing down creek left bank view and existing buffer February 2, 2017 VIA 405 Apartments Enclosure Date 2017 Stream Memo Site Photographs Page 4 Creek substrate within the property boundary February 2, 2017 Creek showing rip rap and trash in the creek within the property boundary February 2, 2017 VIA 405 Apartments Enclosure Date 2017 Stream Memo Site Photographs Page 5 Creek with debris in the channel within the property boundary February 2, 2017 Creek substrate in area with rip rap within the property boundary February 2, 2017 VIA 405 Apartments Enclosure Date 2017 Stream Memo Site Photographs Page 6 Creek (looking down stream) with existing parking and curb within the property boundary February 2, 2017 Creek (looking up stream) with existing parking and curb within the property boundary February 2, 2017