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HomeMy WebLinkAboutP_Off-Site_Benefit_Parcel_Final_Mitigation_Plans_210218_V1.pdfWRI PROJECT #19300Date: 2/10/2021SHEET 1/2FINAL MITIGATION PLANOFF-SITE BENEFIT PARCELRENTON, WASHINGTONPREPARED FOR: Blue Fern Development, LLCAttn: Michelle Branley1414 Market St, #200Kirkland, WA 980039505 19TH AVE SE, SUITE 106EVERETT, WA 98208TEL: 425.337.3174FAX: 425.337.3045Drawn by: A. RichardsonWETLAND A CATEGORY IV 50' BUFFER WETLAND B CATEGORY IV 50' BUFFER WETLAND C CATEGORY IV 50' BUFFER STREAM A TYPE F 115' BUFFER STREAM B TYPE Ns 50' BUFFER LEGEND WETLAND STREAM BUFFER BUFFER ENHANCEMENT FENCING CRITICAL AREA SIGNS X BUFFER ENHANCEMENT 40,359 SF Scale 1" = 30' 3015 45 600 X X X X X X X X X X X X X X X LAKE WASHINGTON BLVDNES88°47'49"E 287.93 S00°55'52"W414.74S81°12'12"E 68.16 N28°48'38"E442.45115'50'50'CONTINEGENCY PLAN If 20% of the plants are severely stressed during any of the inspections , or it appears 20 percent may not survive, additional plantings of the same species may be added to the planting area. Elements of a contingency plan may include, but will not be limited to: more aggressive weed control, pest control, mulching , replanting with larger plant material, species substitution , fertilization , soil amendments , and/or irrigation . PROJECT SUCCESS & COMPLIANCE Criteria for Success Upon completion of the proposed mitigation project, an inspection by a qualified biologist will be made to determine plan compliance . A compliance report will be supplied to the City of Renton within 30 days after the completion of planting . A landscape professional or wetland professional will perform condition monitoring of the plantings in the spring and fall of each monitored year. A written report describing the monitoring results will be submitted to the City after each site inspection of each monitored year. Final inspection will occur five years after completion of this project. The contracted consultant will prepare a report as to the success of the project. Definition of Success The planting areas shall meet the following performance standards: a)End of Year 1 • 100 percent survival of newly planted species and • Less than 20 percent cover of weedy/invasive species b)End of Year 2 • 80 percent survival of newly planted species • Less than 20 percent cover of weedy/invasive species c)End of Year 3 • At least 50 percent native vegetation coverage within the mitigation areas* • Less than 20 percent cover of weedy/invasive species d)End of Year 5 • At least 80 percent aerial cover of native woody plant species*, • Less than 20 percent cover of weedy/invasive species. *Volunteering native species may be included in the aerial cover calculations . The species mix should resemble that proposed in the planting plans, but strict adherence to obtaining all of the species shall not be a criterion for success. MONITORING REPORT CONTENTS Monitoring reports shall be submitted by December 31 of each year during the monitoring period . As applicable , monitoring reports must include descriptions / data for: 1. Site plan and vicinity map 2. Historic description of project , including date of installation , current year of monitoring, restatement of enhancement goals, and performance standards 3. Plant survival, vigor, and areal coverage for every plant community (transect or sampling point data), and explanation of monitoring methodology in the context of assessing performance standards 4. Wetland and buffer conditions, e.g., surrounding land use, use by humans, and/or wild and domestic creatures 5. Observed wildlife, including amphibians , avians , and others 6. Assessment of nuisance / exotic biota and recommendations for management 7. Color photographs taken from permanent photo-points that shall be depicted on the monitoring report map PROJECT MONITORING PROGRAM Requirements for Monitoring Project: 1. Initial compliance/as-built report 2. Site inspection (twice per year) for five years 3. Annual reports (one report submitted during each monitored year) Purpose for Monitoring The purpose for monitoring this mitigation project shall be to evaluate its success. Success will be determined if monitoring shows at the end of five years that the definitions of success stated below are met. The property owner shall grant access to the mitigation area for inspection and maintenance to the contracted landscape and/or wetland specialist and City of Renton during the monitoring period or until the project is evaluated as successful. Monitoring Monitoring shall be conducted twice annually for five years in accordance with the approved Mitigation Plan. The monitoring period will begin once the City receives written notification confirming the mitigation plan has been implemented and City staff inspects the site and issues approval of the installation . Vegetation Monitoring Sampling points or transects will be established for vegetation monitoring and photo points will be established from which photos will be taken throughout the monitoring period. Permanent sampling points must be identified on the mitigation site plans in the first monitoring report (they may be drawn on approved plans by hand). Each sampling point shall detail herbaceous , shrub, and tree coverage . Monitoring of vegetation sampling points shall occur once per monitored year. Wetland Hydrology Monitoring To ensure that wetland hydrology is not impacted by the development , the wetland boundaries will be reviewed during the spring monitoring visit of each monitored year. If it appears that any existing wetland areas are no longer saturated or inundated for sufficient duration to support wetland conditions , those areas will be demarcated in the field and depicted on a map . Additional mitigation may need to be provided , as described in the contingency plan in Section 15, below. Photo points No less than four permanent photo points will be established within the mitigation areas. Photographs will be taken from these points to visually record condition of the mitigation areas. Photos shall be taken annually between May 15 and September 30 (prior to leaf drop), unless otherwise specified . INTRODUCTION Wetland Resources, Inc. (WRI) conducted site investigations on October 18, 2019 to locate wetlands and streams on and in the vicinity of the investigation area, which is composed of King County tax parcel 3343300861 . The site is approximately 1.9-acres, located west of the intersection of Lake Washington Boulevard NE and Southeast 73rd Street in the City of Renton, Washington (Section 29, Township 24N, Range 5E, W.M. The body of this report presents findings regarding the wetlands and streams on-site. SITE DESCRIPTION The investigation area is located within the May Creek sub-basin of the Cedar River/Lake Washington Watershed (WRIA 8). Lake Washington is approximately 600 feet west of the subject property. Surrounding land use is generally residential and undeveloped land with Interstate 405 border the site along its western boundary. The site is undeveloped, and vegetation is mostly dominated by native species with areas of Himalayan blackberry in the understory. Topography is generally a moderate to steep west aspect Three wetlands (Wetlands A through C) and two stream (Streams A and B) were identified within the investigation area. Pursuant to Renton Municipal Code (RMC), on-site wetlands were classified under the Washington State Wetland Rating System for Western Washington: 2014 Update (Hruby 2014). Wetlands A, B, and C are classified as Category IV wetlands. Per RMC (7)(a) the on-site streams were classified based on the WAC 222-16-030 . As such, Stream A is classified as a Type F Stream and Stream B is classified as a Type Ns. Per 4-3-050(G)(2), Category IV wetlands typically receive 50-foot buffers, (when adjacent to non-low impact land uses), Type F streams typically receive a 115-foot buffer, and Type Ns streams typically receive 50-foot buffers. PROJECT DESCRIPTION The applicant has purchased this property for the purpose of conservation. The intent is to enhance and permanently protect this property for the public benefit. BUFFER ENHANCEMENT PLAN As part of the conservation plan for the off-site benefit parcel, the applicant is proposing to enhance the degraded portions of the buffers associated with all the on-site critical areas. The buffer enhancement will involve removing invasive species and planting native trees and shrubs. Prior to planting, invasive woody species including (but not limited to) Himalayan blackberry (Rubus armeniacus) and English holly (Ilex aquifolium) will be removed from the buffer enhancement area. Any existing native plants within the buffer shall be retained and protected. The following native trees, shrubs, and groundcover will be planted in the buffer enhancement area. **Please note that plant quantities provided above are estimates . Actual plant quantities will be determined in the field following invasive species removal to achieve the specified plant densities.** PROJECT NOTES Pre-Construction Meeting Mitigation projects are typically more complex to install than to describe in plans . Careful monitoring by a wetland professional for all portions of this project is strongly recommended. Construction timing and sequencing is important to the success of this type of project. There will be a pre-construction meeting on this site between the Permittee , the consulting wetland professional, and laborers. The objective will be to verify the location of erosion control facilities , verify the location of mitigation areas, and to discuss project sequencing. Inspections A wetland professional shall be contracted to periodically inspect the mitigation installation described in this plan. Minor adjustments to the original design may be necessary prior to and during construction due to unusual or hidden site conditions . A City of Renton representative and/or the consulting professional will make these decisions during construction. WRI PROJECT #19300Date: 2/10/2021SHEET 2/2FINAL MITIGATION PLANOFF-SITE BENEFIT PARCELRENTON, WASHINGTONPREPARED FOR: Blue Fern Development, LLCAttn: Michelle Branley1414 Market St, #200Kirkland, WA 980039505 19TH AVE SE, SUITE 106EVERETT, WA 98208TEL: 425.337.3174FAX: 425.337.3045Drawn by: A. RichardsonSPLIT RAIL FENCE NOTES: 1. Sign placement shall be subject to the approval of the City of Renton. Alternative sign designs may be submitted to the City of Renton for approval. 3. All signs must be secure and permanent. CRITICAL AREA PROTECTION AREA SIGN INSTALLATION GUIDELINES NOT TO SCALE CRITICAL AREA PROTECTION AREA 12"x 18" Aluminum sign with white reflective background . Install one per protected feature in a conspicuous place . Minimum of two galvanized or stainless steel wood lag bolts to firmly secure sign.5 ft. 2 ft. min. 4' X 4' pressure treated wooden post with 1/2" chamfer at top. Magnetic locator pin (e.g., pipe, rebar, 20 penny nail, etc.) placed 8-12" from post along CAPA line. Quick-set concrete Compacted native material6" THIS AREA IS PROTECTED TO PROVIDE WILDLIFE HABITAT AND MAINTAIN CRITICAL AREA(S) FUNCTIONS/VALUES . PROTECTION OF THIS NATURAL AREA IS IN YOUR CARE. ALTERATION OR DISTURBANCE IS PROHIBITED BY LAW FENCING & SIGNAGE Per RMC 4-3-050(G)(3)(f)-(h) outlines fencing and signage requirements . Prior to construction, the outer extent of the approved critical area buffer and areas not to be disturbed shall be marked with high visibility orange construction fencing and silt fencing. Subsequently, permanent fencing of the native growth protection area containing critical area shall be installed , along with permanent signs (made of wood or metal, adhered to treated or metal posts). Sign locations and size specifications shall be approved by the city. RMC 4-3-050(G)(3)(h) recommends the following wording for signs, “Protection of this natural area is in your care. Alteration or disturbance is prohibited by law.” PLANTING NOTES CONT'D Fertilizer Slow release fertilizer may be used if pre-approved by City of Renton staff . Fertilizers shall be applied only at the base of plantings underneath the required covering of mulch (that does not make contact with stems of the plants). No soil amendment or fertilizers will be placed in planting holes . Staking Most shrubs and many trees DO NOT require any staking. If the plant can stand alone without staking in a moderate wind, do not use a stake. If the plant needs support, then strapping or webbing should be used as low as possible on the trunk to loosely brace the tree with two stakes. Do not brace the tree tightly or too high on the trunk. If the tree is unable to sway, it will further lose the ability to support itself. Do not use wire in a rubber hose for strapping as it exerts too much pressure on the bark. As soon as supporting the plant becomes unnecessary, remove the stakes. All stakes must be removed within two (2) years of installation. Plant Location Colored surveyors ribbon or other appropriate marking shall be attached to the installed plants to assist in locating the plants while removing the competing non-native vegetation and during the monitoring period. Arrangement and Spacing The plants shall be arranged in a pattern with the appropriate numbers, sizes, species, and distribution that are required in accordance with the approved plans. The actual placement of individual plants shall mimic natural , asymmetric vegetation patterns found on similar undisturbed sites in the area. Spacing of the plantings may be adjusted to maintain existing vegetation with the agreement of the landscape designer, wetland professional, and/or City staff. Inspection(s) A wetland professional shall be present on site to inspect the plants prior to planting. Minor adjustments to the original design may be required prior to and during construction . Woodchip Mulch All landscaped areas denuded of vegetation and soil surface surrounding all planting pit areas shall receive no less than 2 to 4 inches of certified woodchip mulch after planting. A layer of woodchip mulch will be placed around the base of each plant in a 3-foot radius and at a depth of 2 to 4 inches. The woodchip mulch shall not be allowed to contact plant stems in order to avoid plant decay and rot. MAINTENANCE The mitigation areas will require periodic maintenance to remove undesirable species and replace vegetation mortality. Maintenance shall occur in accordance with the approved plans. Chemical control, only if approved by City staff, shall be applied by a licensed applicator following all label instructions. Duration and Extent In order to achieve performance standards, the permittee shall have the mitigation area maintained for the duration of the five-year monitoring period . Maintenance will include: watering , weeding around the base of installed plants, pruning, replacement , re-staking, removal of all classes of noxious weeds (see Washington State Noxious Weeds List, WAC 16-750-005) as well as Himalayan blackberry, and any other measures needed to ensure plant survival . The landscape designer and/or wetland professional shall direct all maintenance . Survival The permittee shall be responsible for the health of 100% of all newly installed plants for one growing season after installation has been accepted by the City of Renton. A growing season for these purposes is defined as occurring from spring to spring (March 15 to March 15 of the following year). For fall installation (often required), the growing season will begin the following spring. The permittee shall replace any plants that are: failing , weak , defective in manner of growth , or dead during this growing season, as directed by the landscape designer, wetland professional , and/or City of Renton staff . Installation Timing for Replacement Plants Replacement plants shall be installed between September 15 and January 15, unless otherwise determined by the landscape designer, wetland professional , and/or City of Renton staff . Standards for Replacement Plants Replacement plants shall meet the same standards for size and type as those specified for the original installation , unless otherwise directed by the landscape designer, wetland professional , and/or City of Renton staff. Replanting Plants that have settled in their planting pits too deep, too shallow, loose , or crooked shall be replanted as directed by the landscape designer, wetland professional , and/or City of Renton staff . Herbicides / Pesticides In general, chemical controls shall not be used in the mitigation area, sensitive areas, or their buffers. However, limited use of herbicides may be approved depending on site-specific conditions, only if approved by City of Renton staff . Irrigation / Watering Water shall be provided during the dry season (July 1 through October 15) for the first two years after installation to ensure plant survival and establishment . A temporary above ground irrigation system shall be installed within the Stream S buffer enhancement area and Wetland B buffer enhancement area to provide water. Water shall be applied at a rate of 1” of water twice per week for year one and 1” per week during year two. If the mitigation plantings meet 80 percent survival at the end of year two, the system may be removed . General The permittee shall include in general maintenance activities the replacement of any vandalized or damaged signs, habitat features, fences, or other structural components of this mitigation site. PLANTING NOTES Plant in the early spring or late fall and obtain all plants from a reputable nursery. Care and handling of all plant materials is extremely important to the overall success of the project. The origin of all plant materials specified in this plan shall be native plants, nursery grown in the Puget Sound region of Washington . Some limited species substitution may be allowed, only with the agreement of the landscape designer, wetland professional , and/or City staff. Pre-Planting Meeting Prior to control of invasive species or installation of mitigation plantings, a site meeting between the contracted landscaper and the consulting wetland professional shall occur to resolve any questions that may arise. During this meeting a discussion regarding plant spacing and locations of plant species including wetland verses buffer species shall occur between the landscape contractor and the consulting wetland professional. Handling Plants shall be handled so as to avoid all damage , including: breaking , bruising , root damage, sunburn, drying, freezing or other injury. Plants must be covered during transport. Plants shall not be bound with wire or rope in a manner that could damage branches. Protect plant roots with shade and wet soil in the time period between delivery and installation. Do not lift container stock by trunks, stems, or tops. Do not remove from containers until ready to plant. Water all plants as necessary to keep moisture levels appropriate to the species horticultural requirements . Plants shall not be allowed to dry out. All plants shall be watered thoroughly immediately upon installation. Soak all containerized plants thoroughly prior to installation . Storage Plants stored by the Permittee for longer than one month prior to planting shall be planted in nursery rows and treated in a manner suitable to those species’ horticultural requirements. Plants must be re-inspected by the wetland professional and/or landscape designer prior to installation . Damaged plants Damaged , dried out, or otherwise mishandled plants will be rejected at installation inspection . All rejected plants shall be immediately removed from the site. Plant Names Plant names shall comply with those generally accepted in the native plant nursery trade. Any question regarding plant species or variety shall be referred to the landscape designer, wetland professional , or City staff . All plant materials shall be true to species and variety and legibly tagged. Quality and condition Plants shall be normal in pattern of growth, healthy, well-branched , vigorous , with well-developed root systems, and free of pests and diseases. Damaged, diseased, pest-infested , scraped, bruised, dried out, burned, broken, or defective plants will be rejected. Plants with pruning wounds over 1-inch in diameter will be rejected . Roots All plants shall be balled and burlapped (B &B) or containerized , unless explicitly authorized by the landscape designer and/or wetland professional . Rootbound plants or B&B plants with damaged, cracked , or loose rootballs (major damage) will be rejected. Immediately before installation , plants with minor root damage (some broken and/or twisted roots) must be root-pruned. Matted or circling roots of containerized plantings must be pruned or straightened, and the sides of the root ball must be roughened from top to bottom to a depth of approximately half an inch in two to four places . Bare root plantings of woody material are allowed only with permission from the landscape designer, wetland professional and/or City staff. Sizes Plant sizes shall be the size indicated in the plant schedule in approved plans. Larger stock may be acceptable provided that it has not been cut back to the size specified, and that the root ball is proportionate to the size of the plant. Smaller stock may be acceptable , and preferable under some circumstances , based on site-specific conditions. Measurements , caliper, branching , and balling and burlapping shall conform to the American Standard of Nursery Stock by the American Association of Nurserymen (latest edition). Form Evergreen trees shall have single trunks and symmetrical , well-developed form. Deciduous trees shall be single trunked unless specified as multi-stem in the plant schedule. Shrubs shall have multiple stems and be well-branched . Timing of Planting Unless otherwise approved by City staff, all planting shall occur between November 1 and March 1. Overall, the earlier plants go into the ground during the dormant period, the more time they have to adapt to the site and extend their root systems before the water demands of spring and summer. Weeding Existing and exotic vegetation in the mitigation areas will be hand-weeded from around all newly installed plants at the time of installation and on a routine basis throughout the monitoring period. No chemical control of vegetation on any portion of the site is recommended . Site conditions The contractor shall immediately notify the landscape designer and/or wetland professional of drainage or soil conditions likely to be detrimental to the growth or survival of plants. Planting operations shall not be conducted under the following conditions: freezing weather, when the ground is frozen, excessively wet weather, excessively windy weather, or in excessive heat. Planting Pits Planting pits shall be circular or square with vertical sides, and shall be 6” deeper and 12” larger in diameter than the root ball of the plant. Break up the sides of the pit in compacted soils. Set plants upright in pits. Burlap shall be removed from the planting pit. Backfill shall be worked back into holes such that air pockets are removed without adversely compacting down soils. Prune diseased and broken branches Water basin with 3-4" mulch Unglazed planting pit surface 1/2 topsoil, 1/2 native soil, water thoroughly, fertilize TREE PLANTING DETAIL No Scale Planting pit min. twice size of root ball 6" min. SHRUB PLANTING DETAIL No Scale Compacted topsoil water thoroughly, fertilize as req'd Water basin with 3-4" of mulch Prune diseased and broken branches Planting hole min. twice size of root ball PLANT INSTALLATION GUIDELINES