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Home My WebLink AboutR-417990STREAM A T..o� � %i WETLAND C WETLAND CATEGORY 50' BUFFE STREAM TYPE P 50' BUFFE WETLAND CATEGORY 50' BUFFE BUFFER ENHANCEMENT 40,359 SF NT DEVELOPMENT ENGINEERING msippo 05/10/2022 1 :0:1 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. 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 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. 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 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. 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. Buffer Enhancement Plan (40,359 square feet) Common Name Latin Name Size Spacing Quantity Douglas Fir Pseudotsuga menziesii 1 gallon 20 50 Western red cedar Thuja plicata 1 gallon 20' 50 Vine maple Acer circinatum 1 gallon 10, 152 Snowberry Symphoricarpos albus 1 gallon 10' 151 Sword fern Polystichum munitum 1 gallon 6' 359 Low Oregon grape Mahonia nervosa 1 gallon 6' 359 **Please note that plant quantities provided above quantities will be determined in the field following achieve the specified plant densities. ** are estimates. Actual plant invasive species removal to R-41 7990 o � 0 0 o� � o � � o Q Q co n�, o vt�j+ c� `Z `w ~ co co CD wco N -.I- ocoM CD ;QMM co co _ CO CO jNLO �. `D J X ` Ln > w Q rnw�u_ w O O 00 �4 1_4 102 of 107