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HomeMy WebLinkAboutEx 13_Stream Study & Buffer Mitigation Plan.pdf STREAM STUDY & BUFFER MITIGATION PLAN FOR SUNSET HIGHLANDS RENTON, WA Wetland Resources, Inc. Project #24120 Prepared By Wetland Resources, Inc. 9505 19th Avenue SE, Suite 106 Everett, WA 98208 (425) 337-3174 Prepared For ADF Properties LLC Attn: Dale Fonk 15007 Woodinville-Redmond Rd, #A Woodinville, WA 98072 May 30, 2024 ii TABLE OF CONTENTS 1.0 INTRODUCTION .........................................................................................................................1 1.1 SITE DESCRIPTION ..............................................................................................................................1 2.0 STREAM DETERMINATION REPORT ..........................................................................................4 2.1 PUBLICLY AVAILABLE DATA ...............................................................................................................4 2.2 STREAM DETERMINATION METHODOLOGY .....................................................................................4 2.3 STREAM DETERMINATION .................................................................................................................4 3.0 OTHER CRITICAL AREAS ...........................................................................................................5 3.1 HABITAT CONSERVATION AREAS/HABITAT ASSESSMENT ..............................................................6 3.2 WETLANDS ..........................................................................................................................................6 3.3 FLOOD HAZARD AREAS ......................................................................................................................6 4.0 PROJECT DESCRIPTION ..............................................................................................................6 4.1 COMPLIANCE WITH RENTON MUNICIPAL CODE ..............................................................................7 5.0 BUFFER MITIGATION PLAN ......................................................................................................13 5.1 SITE PREPARATION ...........................................................................................................................13 5.2 BUFFER ENHANCEMENT PLANTING PLAN .......................................................................................13 5.3 PROJECT NOTES ................................................................................................................................14 5.4 PLANTING NOTES ..............................................................................................................................14 6.0 FUNCTIONS AND VALUES ASSESSMENT ...................................................................................17 6.1 EXISTING CONDITIONS ....................................................................................................................17 6.2 POST CONSTRUCTION FUNCTIONS AND VALUES ...........................................................................17 7.0 PROJECT MONITORING PROGRAM ..........................................................................................18 7.1 REQUIREMENTS FOR MONITORING PROJECT: ................................................................................18 7.2 MONITORING REPORT CONTENTS .................................................................................................19 8.0 PROJECT SUCCESS & COMPLIANCE .........................................................................................19 8.1 CRITERIA FOR SUCCESS ...................................................................................................................19 8.2 DEFINITION OF SUCCESS ..................................................................................................................19 9.0 MAINTENANCE .........................................................................................................................20 10.0 CONTINGENCY PLAN .............................................................................................................21 11.0 FENCING & SIGNAGE ..............................................................................................................22 12.0 COST ESTIMATE & SURETY DEVICE ......................................................................................22 13.0 USE OF THIS REPORT ............................................................................................................23 14.0 REFERENCES ..........................................................................................................................24 iii LIST OF FIGURES FIGURE 1 - AERIAL VIEW OF THE SUBJECT PROPERTY. ....................................................................2 FIGURE 2 -EXISTING CONDITIONS ON THE SITE (FACING SOUTHWEST FROM THE NORTHEAST CORNER). (PHOTO TAKEN APRIL 12, 2024.) .....................................................................................3 FIGURE 3 -EXISTING CONDITIONS OF THE VEGETATED PART OF THE STREAM BUFFER. (PHOTO TAKEN APRIL 12, 2024.) ...................................................................................................................3 FIGURE 4 -HONEY CREEK ON THE SUBJECT SITE. (PHOTO TAKEN APRIL 12, 2024) .......................5 LIST OF APPENDICES APPENDIX A: EXISTING CONDITIONS MAP (SHEET 1/2) APPENDIX B: STREAM STUDY & BUFFER MITIGATION PLAN MAP (SHEET 2/2) Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 1 May 30, 2024 1.0 INTRODUCTION Wetland Resources, Inc. (WRI) conducted site investigations on December 22, 2022, and April 12, 2024, to verify the ordinary high water mark and evaluate stream conditions on the property located at 4409 Sunset Boulevard NE in Renton, WA. In December 2022 the adjacent portions of the open channel of Honey Creek, which generally flows between Anacortes Ave NE and Whitman Ct NE were also investigated. The purpose of this report is to provide a stream and buffer determination, assess impacts associated with the proposed Sunset Highlands development project, demonstrate compliance with Renton Municipal Code Critical Areas Regulations and variance requirements, and provide a buffer mitigation plan. 1.1 SITE DESCRIPTION The 0.81-acre property consists of one tax parcel (number 0323059093) and is further identified as a portion of Section 3, Township 23N, Range 5E, W.M. The site is situated within the May Creek drainage basin in the Cedar-Sammamish Watershed (WRIA 8). The property is zoned Commercial Arterial (CA). No structures are located on the property. Approximately 70 percent of the parcel consists of gravel associated with a city construction project. Remnants of a split-rail fence are located approximately 25 feet from Honey Creek, which crosses the southeastern corner of the property. Vegetation on the site consists of maintained grass and weedy herbaceous vegetation with trees and shrubs in the area immediately adjacent to the stream. Extensive trash/debris were observed in the stream and riparian area during the site investigation. Topography of the site has a slight south-facing aspect from Sunset Boulevard NE to Honey Creek. Surrounding land use consists of dense commercial and multi-family residential development. Honey Creek is classified as a Type F stream and is designated a 115-foot buffer with an additional 15-foot structure setback. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 2 May 30, 2024 - Aerial view of the subject property. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 3 May 30, 2024 -Existing conditions on the site (facing southwest from the northeast corner). (Photo taken April 12, 2024.) -Existing conditions in the vegetated part of the stream buffer. (Photos taken April 12, 2024.) Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 4 May 30, 2024 2.0 STREAM DETERMINATION REPORT 2.1 PUBLICLY AVAILABLE DATA Prior to conducting the site investigation, public resource information was reviewed to gather background information on the subject property and the surrounding area in regard to streams. These sources included the following: • Washington Department of Fish and Wildlife (WDFW) SalmonScape Interactive Mapping System SalmonScape does not depict the short stretch of the open stream on and near the subject property. It does map fish distribution terminating approximately 500 feet downstream of Union Ave NE. • WDNR Forest Practices Application Mapping Tool (FPAMT) This resource depicts Honey Creek as a Type N stream approximately 500 feet downstream of Union Ave NE and as a Type F stream slightly less than one mile downstream of Union Ave NE. The on-site portion of the stream is not classified or depicted. • City of Renton COR Maps The City of Renton online interactive map depicts the entirety of “Honey Creek” from its origin near the northern terminus of Kitsap Ave NE until its confluence with May Creek. The piped sections of the stream under both public and private infrastructure are identified. Stream typing data is not identified on the City of Renton mapping. • City of Renton Sensitive Areas Wetlands and Water Classification Map (pdf) This map depicts the Honey Creek as a Type Np – Non-Fish Perennial stream below Union Ave NE and a Type Ns – Non-Fish Seasonal stream above. 2.2 STREAM DETERMINATION METHODOLOGY The ordinary high water mark (OHWM) of streams were identified using the methodologies described in the Washington State Department of Ecology (DOE), Determining the Ordinary High Water Mark for Shoreline Management Act Compliance in Washington State (Anderson et al. 2016). 2.3 STREAM DETERMINATION 2.3.1 Honey Creek City of Renton Classification: Type F City of Renton Buffer: 115 feet Honey Creek flows onto the southeastern corner of the subject site via a culvert. It flows in an open channel across the site and beyond for a distance of approximately 220 feet where it again enters the piped stormwater drainage system. It is piped for a distance of approximately 665 feet, flows into another open channel for about 100 feet and then is piped again for approximately 155 feet. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 5 May 30, 2024 It then flows into an open channel to its mouth at Puget Sound. The on-site stream ordinary high water mark was verified by WRI on April 12, 2024. Multiple studies have been conducted on this stream reach with varying stream type determinations. Per communication with the City of Renton, the on-site portion of Honey Creek has been determined to be a Type F stream because it could support fish species if human made fish passage barriers downstream were to be removed. Per RMC 4-3-050G.2, Type F streams are designated 115-foot buffers with an additional 15-foot structure setback. -Honey Creek on the subject site. (Photo taken April 12, 2024) 3.0 OTHER CRITICAL AREAS In addition to streams, the City of Renton regulates geologically hazardous areas, landslide hazards, erosion hazards, seismic hazards, coal mine hazards, wellhead protection areas, habitat conservation areas, wetlands, and flood hazard areas. Assessment of geologically hazardous areas, landslide hazards, erosion hazards, seismic hazards, coal mine hazards, and wellhead protection areas are outside the scope of this report. No other critical areas were identified on or near the subject property, as described below. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 6 May 30, 2024 3.1 HABITAT CONSERVATION AREAS/HABITAT ASSESSMENT Per RMC 4-3-050G.6, habitat conservation areas are defined as habitats that have a primary association with the documented presence of non-salmonid or salmonid species proposed or listed by the Federal government or State of Washington as endangered, threatened, sensitive and/or of local importance. The Washington Department of Fish and Wildlife (WDFW) Priority Habitats and Species online mapping tool does not indicate any species or habitats of concern on or near the subject property. No documented presence of salmonid species is mapped by WDFW’s SalmonScape mapping tool and no Type F streams are mapped by the Washington Department of Natural Resources Forest Practices Application Mapping Tool on or near the property. The on- site stream is seasonally flowing and is inaccessible to anadromous fish due to human made barriers downstream. Therefore, the on-site portion of Honey Creek does not support fish in its current condition. Given the existing condition of the subject site and surrounding properties, no species or habitats of concern are located on or near the site. Per RMC 4-3-050F.7, in cases where a proposal is not likely to significantly impact the critical habitat and there is sufficient information to determine the effects of a proposal, an applicant may request the requirement for a Habitat Assessment be waived. As no species or habitats of concern are located on or near the subject property, the proposed project will not impact critical habitat. Therefore, the applicant requests that the Habitat Assessment for this project be waived. 3.2 WETLANDS No wetlands are depicted on or near the property on the US Fish and Wildlife Service (USFWS) National Wetlands Inventory online mapping tool, the City of Renton COR Maps interactive map, or the City of Renton Wetlands and Water Classifications PDF map. No wetlands were identified on or near the property during the site investigations. 3.3 FLOOD HAZARD AREAS The subject property is mapped within Zone X, which is defined as an area of minimal flood hazard and not within a regulated flood hazard area (FEMA FIRM panel 530088). 4.0 PROJECT DESCRIPTION The applicant proposes to construct a medical facility with associated parking on the property. Honey Creek and the associated buffer encumber approximately 52 percent of the 0.81-acre property. A reasonable commercial development on the property is not feasible under the standard buffer requirements per RMC 4-3-050G.2 nor the alternative buffer requirements per RMC 4-3- 050I. Therefore, the applicant is requesting a variance. The proposed development has been designed to avoid any direct impacts to Honey Creek and to minimize impacts to the buffer. The medical building is proposed in the northern part of the site, as far from the stream as possible, with parking to be located between the building and the stream. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 7 May 30, 2024 To accommodate the proposed development, the applicant proposes to reduce the stream buffer to 40 feet. The majority of the buffer area that will be reduced consists of gravel. Overall, the development plan requires a reduction of a total of 13,228 square feet of buffer area. Of this area, approximately 9,300 square feet currently consists of gravel and is not vegetated. This area, therefore, does not provide buffer functions and, in fact, generates runoff and pollutants that degrade water quality. The remaining buffer reduction area totals 3,928 square feet and consists primarily of maintained grasses and weedy herbaceous vegetation, which provides a low level of buffer functions and values. After development, stormwater from the site will be diverted to a detention vault and two bioretention swales before discharging to Honey Creek, which will result in a significant improvement in hydrologic and water quality functions on the site as compared with the existing conditions. To compensate for the unavoidable buffer impacts associated with the project, the applicant proposes to enhance the entire remaining buffer between the stream and development, which totals 4,460 square feet. The proposed enhancement measures include removal of trash/debris and invasive species, installation of a diverse mix of native trees and shrubs, and installation of permanent fencing and signs along the perimeter of the modified buffer. Temporary buffer impacts will occur for the installation of a stormwater conveyance pipe to the stream and for a small amount of grading along the edge of the modified buffer. These areas will be restored as part of the buffer enhancement plan. The on-site stream and buffer will be designated as a Native Growth Protection Area, which will be protected in perpetuity. In addition to improving hydrologic and water quality functions on the site, the proposed plan will improve the functions of the buffer by discouraging human intrusion, providing noise and visual screening between the stream and the development, and by significantly improving wildlife habitat functions. Overall, the proposed plan will improve the functions and values of the on-site stream and buffer. (Refer to section 6.0 for a detailed assessment or pre- and post-project functions and values.) 4.1 COMPLIANCE WITH RENTON MUNICIPAL CODE The following sections demonstrate compliance of the proposed development with the applicable provisions of Renton Municipal Code (RMC). 4.1.1 Criteria for permit approval for projects near streams RMC states that projects located on or near regulated streams will be reviewed pursuant to the following criteria (applicable code cited in italics with responses beneath in normal text). 4-3-050G.7.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 Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 8 May 30, 2024 It is not feasible to achieve a reasonable commercial development plan for the site that would comply with the standard provisions as over half of this small property is encumbered by the on- site stream and buffer. 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 Alternative administrative standards require a minimum 90-foot stream buffer. This would result in a total of 21,663 square feet of area outside the buffer, which is not sufficient to accommodate a reasonable commercial development with the required parking. 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. Due to the constraints described above, the applicant is requesting a variance. The existing riparian area (the upland area immediately adjacent to and paralleling Honey Creek, which consists of grasses and weedy herbaceous species with sparse trees and shrubs) will be retained and enhanced, which will ensure no net loss of riparian area and provide an overall improvement in riparian functions. Functions provided by riparian areas include channel stability, sustained water supply, flood storage, recruitment of woody debris, leaf litter, and nutrients, sediment and pollutant filtering, shade, and shelter. Most of the buffer area that will be reduced consists of unvegetated gravel. A total of 3,928 square feet of buffer that contains maintained grasses and weedy herbaceous species will be impacted. The buffer areas that will be reduced for this project do not contribute to channel stability and do not provide sustained water supply or flood storage. They do not contain trees or shrubs that would contribute to the recruitment of large, woody debris or leaf litter or provide shade or shelter. The maintained area that is not gravel provides a small amount of filtration of sediments and pollutants, but these functions are degraded by extensive trash/debris that has been discarded in these areas. The proposed mitigation plan will result in the enhancement of the remaining buffer on the site, which will expand the extent of the functional riparian area. Enhancement measures will include removal of trash/debris and invasive species and the establishment of a dense native vegetation community. These measures will significantly increase protection of the stream by reducing human encroachment, increasing noise and visual screening, and improving wildlife habitat. Riparian functions including filtration of sediment and pollutants, large, woody debris and leaf litter recruitment, and the provision of shade and shelter will also be improved. Stormwater management measures that will be implemented as part of the development plan will improve water quality on the site. Permanent fencing and signs will be installed on the edge of the on-site buffer to further limit human intrusion. Overall, the project will result in a significant lift in stream protection and riparian functions as compared with the current conditions. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 9 May 30, 2024 4.1.2 Stormwater conveyance and discharge The proposed plan includes a stormwater conveyance pipe through the buffer to outfall to Honey Creek. Per RMC 4-3-050C.3, new surface water discharges are permitted within Type F streams. Per RMC 4-3-050C.4, stormwater conveyance is allowed within the buffer on a Type F stream. Installation of the stormwater conveyance pipe will result in temporary impacts to buffer vegetation. No trees will be removed, and the entire buffer will be enhanced with native trees and shrubs following construction. Therefore, no permanent impacts to buffer functions will occur for the installation of the stormwater conveyance and outfall. 4.1.3 Mitigation Sequencing Per RMC 4-3-050H.2, development proposals must be designed to avoid and minimize impacts to critical areas and buffers based on the following criteria, in the order listed: a. Avoid any disturbances to the critical area or buffer; Direct impacts to the on-site stream have been avoided. Due to the relatively small size of the property and the extent of the on-site stream and buffer, it is not feasible to design a reasonable development on the property that would avoid any impacts to the buffer. b. Minimize any critical area or buffer impacts; Over half of the 0.81-acre property is encumbered by the stream and buffer. The remaining portion of the property is not sufficient to accommodate a reasonable commercial development with required parking. The majority of the buffer area that will be reduced consists of gravel and does not currently provide any buffer functions. The vegetated portion of the buffer that will be permanently impacted totals 3,928 square feet and represents the minimum impact necessary to achieve a reasonable development on the site. Temporary buffer impacts for the installation of a stormwater drainage pipe and outfall will be the minimum necessary and will be restored as part of the buffer enhancement plan. c. Compensate for any critical area or buffer impacts; No direct critical area impacts are proposed. To compensate for 3,928 square feet of impact to buffer that consists primarily of maintained grasses and weedy herbaceous species, the applicant will enhance the entire remaining buffer on the site. The proposed buffer enhancement area totals 4,460 square feet. Trash/debris will be removed from the stream and buffer, invasive species will be removed, and a diverse mix of native trees and shrubs will be planted. The proposed mitigation will improve buffer functions on the site by increasing noise and visual screening, improving wildlife habitat functions, and limiting intrusion by humans and pets into the area surrounding the stream. d. Restore any critical area or buffer temporarily impacted or lost; Permanent buffer impacts cannot be restored. Temporarily impacted buffer areas consist of a mix of native and non-native vegetation. These areas will be restored with native species, which will result in an improvement in buffer functions. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 10 May 30, 2024 e. Create new critical areas and buffers for those lost; and There is no opportunity on the site to create new buffer to replace the area that will be lost. f. Enhance an existing degraded buffer to compensate for lost functions and values in addition to restoring or creating a critical area. The entirety of the remaining buffer on the site will be enhanced, which will significantly improve buffer functions and values on the site. No restoration or creation of a critical area is proposed as no direct impacts to critical areas will occur. 4.1.4 Variance Per RMC 4-9-250B.1.v.b, an administrative variance may be allowed for a buffer width reduction that is not otherwise authorized by RMC 4-3-050 for a Type F stream. The following review criteria apply (applicable code cited in italics with responses beneath in normal text). RMC 4-9-250B 7. Special Review Criteria – Reasonable Use Variance – Critical Areas Regulations Only: For variance requests related to the critical areas regulations not subject to subsections B8 to B13 of this Section, a reasonable use variance may be granted if all of the following criteria are met: The proposed project is not subject to subsections B8 or B13 of this code section. Therefore, the criteria in this subsection apply. a. That the granting of the variance will not be materially detrimental to the public welfare or injurious to the property or improvements in the vicinity and zone in which subject property is situated; The granting of this variance will not be materially detrimental to the public welfare or injurious to the property or improvements in the vicinity and zone. The proposed development is compatible with surrounding land use and is allowed under the property zoning designation. b. There is no reasonable use of the property left if the requested variance is not granted; Because of the small size of the property and the existing constraints associated with the stream and buffer, no reasonable commercial development is viable on the site without the granting of a variance. c. The variance granted is the minimum amount necessary to accommodate the proposal objectives; The objectives are to provide a medical facility with associated parking and stormwater management requirements. The proposed improvements are the minimum necessary to achieve the project objectives, and the improvements have been located as close to Sunset Boulevard NE as possible so as to minimize the encroachment into the stream buffer. d. The need for the variance is not the result of actions of the applicant or property owner; and Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 11 May 30, 2024 The need for the variance is a result of existing conditions on the site and does not result from any actions of the applicant or property owner. e. The proposed variance is based on consideration of the best available science as described in WAC 365-195-905; or where there is an absence of valid scientific information, the steps in subsection F of this Section are followed. The impact assessment and mitigation plan are based on best available science (BAS). BAS sources that have informed this report are included in section 14.0 (References) and includes sources provided by the Washington Department of Ecology for use as BAS in regard to wetlands, streams, and buffers as well as Renton Municipal Code in regard to protection of streams and riparian area functions. BAS supports the assertion that the proposed development and mitigation plan will result in an overall improvement in water quality for the stream and in the protective functions of the on-site buffer and riparian area. 4.1.5 Criteria for reduction of degraded stream buffer with enhancement Although the provisions of RMC 4-3-050I cannot all be met, as the maximum buffer reduction allowed under this subsection is not sufficient to accommodate development of this site, the proposed plan has been designed to comply with the remaining criteria for reduction of a degraded stream buffer with enhancement, as demonstrated below. RMC 4-3-050I 2. Streams: a. Criteria for Reduction of Degraded Stream Buffer Width with Enhancement: A reduced buffer will be approved in a degraded stream buffer only if: i. It will provide an overall improvement in water quality; and The proposed enhancement will include removal of trash/debris in the stream and buffer, which is a source of pollutants. Additionally, the stormwater management measures will improve water quality, and the planting of native trees and shrubs will increase the interception of rainfall and filtration of sediments and pollutants. Once established, the dense vegetative community will also reduce human intrusion into the stream and buffer area (which will in turn reduce or eliminate future deposition of trash/debris). Permanent fencing and signs will further limit human intrusion and deposition of trash/debris. ii. It will provide an overall enhancement to fish, wildlife, or their habitat; and The proposed plan will significantly improve wildlife habitat by removing trash/debris from the stream and buffer, removing invasive species from the buffer, and increasing the density and diversity of native species. The native plantings will provide important forage resources, recruitment of large, woody debris and other organic matter, increase shading, and provide perching and nesting opportunities as well as thermal and hiding shelter for wildlife. The plantings and fencing will limit human intrusion, which will increase protection for wildlife and their habitat. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 12 May 30, 2024 iii. It will provide a net improvement in drainage and/or stormwater detention capabilities; and The proposed planting plan will result in a dense vegetation community, which will increase the interception of rainfall (thus reducing the volume and velocity of surface water flows). iv. It will not be materially detrimental to any other property or the City as a whole; and The proposed plan will not be detrimental to any other property or the City as a whole. The development type is allowed under City zoning and is compatible with surrounding land use. No change to other properties will occur. v. It will provide all exposed areas with stabilized native vegetation, as appropriate; and The entirety of the remaining buffer on the site will be enhanced. With native vegetation. After removal of invasive species and planting of native trees and shrubs, any exposed areas will be stabilized with an appropriate grass seed mix. vi. The request is not made in conjunction with buffer reduction, and The proposed buffer reduction is the minimum necessary to accommodate a reasonable development on the site. vii. It will provide, as part of the buffer reduction request, buffer enhancement plan prepared by a qualified professional and fund a review of the plan by the City’s consultant. The plan shall assess habitat, water quality, stormwater detention, groundwater recharge, shoreline protection, and erosion protection functions of the buffer; assess the effects of the proposed modification on those functions; and address the six (6) criteria listed above. The buffer enhancement plan will result in a significant lift to buffer functions on the site as compared with existing conditions. Please refer to section 6.0 for a detailed assessment of pre- and post-project functions and values. 4.1.6 Structure setback Per RMC 4-3-050G.2, a 15-foot structure setback from the stream buffer shall be provided. Impervious surfaces such as driveways are allowed within this setback. The medical building is setback a minimum distance of approximately 90 feet from the stream buffer. The parking lot is located approximately 13.5 feet from the edge of the buffer at the closest point. Therefore, the site plan is compliant with the required structure setback from the modified 40-foot stream buffer. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 13 May 30, 2024 5.0 BUFFER MITIGATION PLAN To compensate for 3,928 square feet of unavoidable impact to vegetated buffer areas on the subject property, the applicant proposes to enhance the entire remaining buffer between the stream and the proposed development, which totals 4,460 square feet. This represents a greater than one to one buffer mitigation ratio and will result in a net improvement in buffer functions and values on the site. 5.1 SITE PREPARATION Prior to installation of the buffer enhancement planting plan, invasive species shall be removed from the designated buffer enhancement area. Native trees and native shrubs will be retained to the extent possible. Invasive species that are currently present include knotweed (Fallopia sp.), Himalayan blackberry (Rubus armeniacus), and English ivy (Hedera helix). These species require different control techniques, as described below: Knotweed Knotweed shall be treated with an herbicide approved for use in aquatic areas. Herbicide shall be applied by a licensed applicator following all label directions. WRI recommends treating in early- to mid-spring after plants have emerged and are actively growing. Repeated treatments will be necessary. Himalayan Blackberry Himalayan blackberry should be manually removed from the buffer, making sure to grub out roots to prevent re-growth. English Ivy Ivy should be manually removed from the ground, taking care to grub out roots to prevent re- growth. For areas where ivy is growing up the trunks of trees, cut off ivy stems at least 2 feet above ground level and remove from the base of the tree trunks. The remaining ivy on the higher portions of the trees will die back on its own once they are cut off from the roots. All invasive species material shall be removed from the project site immediately after control to be disposed of off-site at an appropriate location and shall be transported in a manner that will avoid the spread of any part of the plants on site or off site. 5.2 BUFFER ENHANCEMENT PLANTING PLAN After site preparation has been completed, the following species will be installed in the buffer enhancement area. These will be interspersed among existing native trees and shrubs. Please note that the plant quantities provided are estimates and may be adjusted to achieve the specified planting densities as needed after site preparation is completed. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 14 May 30, 2024 Following installation of the plants, a three-foot diameter ring of woodchip mulch three to four inches deep shall be placed around each planting pit and over any bare soil areas. Mulch shall be kept at least two inches from plant stems. 5.3 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. 5.4 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 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 shall occur between the landscape contractor and the consulting wetland professional. Common Name Latin Name Size Spacing Quantity Big-leaf maple Acer macrophyllum 1 gallon 10'8 Douglas fir Pseudotsuga menziesii 1 gallon 10'8 Western red cedar Thuja plicata 1 gallon 10'8 Osoberry Oemleria cerasiformis 1 gallon 5'18 Salmonberry Rubus spectabilis 1 gallon 5'40 Snowberry Symphoricarpos albus 1 gallon 5'30 Tall Oregon grape Mahonia aquifolium 1 gallon 5'30 Vine maple Acer circinatum 1 gallon 5'18 Buffer Enhancement Planting Plan (4,460 SF) Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 15 May 30, 2024 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 one 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). Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 16 May 30, 2024 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. Weed Removal Non-native, invasive vegetation in the mitigation area will be removed from the mitigation area prior to planting. Knotweed shall be controlled with herbicide prior to plant installation. Multiple treatments will likely be required. An herbicide approved for use in aquatic areas shall be used and shall be applied by a licensed applicator following all label instructions. After plants have been installed, herbicide use is not recommended on any part of the site. Existing vegetation will be hand-weeded from around all newly installed plants at the time of installation and on a routine basis throughout the monitoring period. 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 six inches deeper and twelve inches 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 soils. 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. 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. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 17 May 30, 2024 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. Attach flagging to lateral branches rather than main trunks whenever possible. 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 native 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. Any adjustments shall be approved by the wetland professional and/or City staff. Woodchip Mulch All landscaped areas denuded of vegetation and soil surface surrounding all planting pit areas shall certified woodchip mulch after planting. A layer of woodchip mulch will be placed around the base of each plant in a three-foot radius and at a depth of three to four inches. The woodchip mulch shall not be allowed to contact plant stems in order to avoid plant decay and rot. 6.0 FUNCTIONS AND VALUES ASSESSMENT Streams in Western Washington provide a variety of functions including transport of water, sediment, and organic matter, floodwater storage and attenuation, habitat for fish and wildlife, and can serve as habitat corridors for aquatic and terrestrial wildlife. 6.1 EXISTING CONDITIONS Honey Creek flows onto the southeastern corner of the subject property from a culvert. It flows through an open channel across the site and continues to the west for approximately 220 feet where it enters another culvert. It is intermittently piped for about another 920 feet where it enters an open channel reach that extends to the mouth at Puget Sound. The on-site portion of the stream is seasonally flowing. It is degraded with extensive trash and debris. The channel is excavated and lacks sinuosity and pools and drops. Large woody debris is present in the channel. The riparian area surrounding the on-site portion of the stream also contains extensive trash and is sparsely vegetated with a mix of native and non-native invasive vegetation. 6.2 POST CONSTRUCTION FUNCTIONS AND VALUES Following construction of the proposed development, stormwater from the site will be diverted to a below ground storage vault and two bioretention swales before being discharged to Honey Creek. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 18 May 30, 2024 This will result in a direct improvement in water quality for the stream. The proposed buffer enhancement includes removing trash/debris and invasive species, installing a dense mix of native trees and shrubs, and installing permanent fencing along the perimeter of the buffer. These measures will significantly reduce or eliminate human intrusion into the stream and buffer area and therefore, the discarding of trash in and around the stream. The plantings will result in dense vegetation that will reduce or eliminate human and pet intrusion, provide noise and visual screening between the development and the stream, increase perching and nesting opportunities and thermal and hiding cover for wildlife, provide native forage resources, increase shading, and result in an increase in the recruitment of large, woody debris and other organic matter. Overall, the proposed development and mitigation plan will provide a significant lift to the functions and values of the on-site stream and buffer. 7.0 PROJECT MONITORING PROGRAM 7.1 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). Monitoring of vegetation sampling points shall occur once per monitored year. Photo points No less than two permanent photo points will be established within the mitigation area. Photographs will be taken from these points to visually record condition of the mitigation area. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 19 May 30, 2024 Photos shall be taken annually between May 15 and September 30 (prior to leaf drop), unless otherwise specified. 7.2 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 aerial coverage for every plant community (transect or sampling point data), and explanation of monitoring methodology in the context of assessing performance standards 4. Stream 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 8.0 PROJECT SUCCESS & COMPLIANCE 8.1 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. If the project has not met the required performance standards by the end of the fifth year, the monitoring period may be extended. 8.2 DEFINITION OF SUCCESS The planting areas shall meet the following performance standards: a) End of Year 1 • 100 percent survival of newly planted species • Less than 10 percent cover of invasive species b) End of Year 2 • 80 percent survival of newly planted species Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 20 May 30, 2024 • Less than 10 percent cover of invasive species c) End of Year 3 • At least 30 percent aerial cover of native woody plant species* • Less than 10 percent cover of invasive species d) End of Year 4 • At least 40 percent aerial cover of native woody plant species* • Less than 10 percent cover of invasive species e) End of Year 5 • At least 60 percent aerial cover of native woody plant species* • Less than 10 percent cover of 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. 9.0 MAINTENANCE The mitigation area 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 percent 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. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 21 May 30, 2024 Installation Timing for Replacement Plants Replacement plants shall be installed between November 1 and March 1, 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 After initial herbicide treatments for knotweed, it is generally not recommended that herbicides be used in the mitigation area. However, limited use of herbicides may be approved depending on site-specific conditions. Any herbicide use shall be approved by the consulting biologist and/or 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 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, irrigation may be discontinued. It is recommended that the irrigation system be maintained on the site for the duration of the monitoring period and must be removed once the project has been deemed successful. General The permittee shall include in general maintenance activities the replacement of any vandalized or damaged signs, fences, or other structural components of this mitigation site. 10.0 CONTINGENCY PLAN If 20 percent 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. Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 22 May 30, 2024 11.0 FENCING & SIGNAGE Per RMC 4-3-050G.3.f-h outlines fencing and signage requirements. Prior to construction, the outer extent of the areas not to be disturbed shall be marked with high visibility orange construction fencing and silt fencing. Subsequently, permanent fencing shall be installed along the edge of the final buffer, 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 4-3-050G.3.h recommends the following wording for signs: “Protection of this natural area is in your care. Alteration or disturbance is prohibited by law.” 12.0 COST ESTIMATE & SURETY DEVICE A surety device shall be provided to the City of Renton to ensure project performance. After the City determines that the mitigation has been successfully completed and the monitoring period has expired, the surety device shall be released. Per RMC 4-3-050L.2.a, a project cost estimate was determined using costs provided on the King County Bond Quantity Worksheet. This estimate is provided for the purpose of determining the amount of the surety device and does not represent a bid to install. The total estimated project cost is as follows: Plants (1 gallon, installed; 160 @ $11.50/each)$1,840.00 Woodchip mulch (126 SY @ $3.25/SY)$409.50 Split rail fencing (162 LF @ $10.54/LF)$1,707.48 Permanent signs (2 @ $28.50/Each)$57.00 Temporary irrigation (0.1 acres @ $3,000/acre)$300.00 General labor (8 hours @$40/hr)$320.00 Maintenance (twice per year - 5 years)$1,800.00 Monitoring (twice per year - 5 years)$7,200.00 Total Estimated Project Cost $13,633.98 Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 23 May 30, 2024 13.0 USE OF THIS REPORT This report is based largely on readily observable conditions and, to a lesser extent, on readily ascertainable conditions. No attempt has been made to determine hidden or concealed conditions. The laws applicable to wetlands are subject to varying interpretations and may be changed at any time by the courts or legislative bodies. This report is intended to provide information deemed relevant in the applicant's attempt to comply with the laws now in effect. The work for this report has conformed to the standard of care employed by wetland ecologists. No other representation or warranty is made concerning the work or this report, and any implied representation or warranty is disclaimed. Wetland Resources, Inc. Joie Goodman, PWS Senior Ecologist Stream Study & Buffer Mitigation Plan Wetland Resources, Inc. #24120 Sunset Highlands 24 May 30, 2024 14.0 REFERENCES Anderson, P., S. Meyer, P. Olson, and E. Stockdale. 2016. Determining the Ordinary High Water Mark for Shoreline Management Act Compliance in Washington State. October 2016 Final Review. Washington State Department of Ecology, Shorelands and Environmental Assistance Program. Lacey, WA. Publication # 16-06-029. King County. King County iMap interactive mapping tool. http://www.kingcounty.gov/operations/GIS/Maps/iMAP.aspx Natural Resources Conservation Service. Web Soil Survey. United States Department of Agriculture. http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx. Sheldon, D., T. Hruby, P. Johnson, K. Harper, A. McMillan, T. Granger, S. Stanley, and E. Stockdale. March 2005. Wetlands in Washington State - Volume 1: A Synthesis of the Science. Washington State Department of Ecology. Publication #05-06-006. Olympia, WA. Renton, City of. Renton Municipal Code. 4-3-050 Critical Areas Regulations (current through Ordinance 6133, passed March 4, 2024). Renton, City of. COR Map Interactive Map. https://maps.rentonwa.gov/Html5viewer/Index.html?viewer=cormaps Renton, City of. Sensitive Areas: Wetlands and Water Classifications Map. December 12, 2022. U.S. Army Corps of Engineers. 2010. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0). U.S. Army Engineer Research and Development Center Environmental Laboratory. Vicksburg, MS. Publication # ERDC/EL TR-10-3. US Fish and Wildlife Service. National Wetlands Inventory (NWI) Wetlands Mapper. http://www.fws.gov/wetlands/Data/Mapper.html Washington State Department of Ecology. 2019. Stormwater Management Manual for Western Washington. Washington State Department of Ecology. July 2019. Publication #19-10-021. Washington State Department of Fish and Wildlife (WDFW). Priority Habitats and Species: PHS on the Web. https://geodataservices.wdfw.wa.gov/hp/phs/ WDFW. SalmonScape online mapping tool. http://apps.wdfw.wa.gov/salmonscape/map.html Washington State Department of Natural Resources. Forest Practices Application Mapping Tool. https://fpamt.dnr.wa.gov/default.aspx APPENDIX A: EXISTING CONDITIONS MAP (SHEET 1/2) APPENDIX B: STREAM STUDY & BUFFER MITIGATION PLAN MAP (SHEET 2/2) DDDDDDDDD DDDD DDDDDD DDDDDDSUNSET HIGHLANDS STREAM STUDY & BUFFER MITIGATION PLAN MAP PORTION OF SECTION 3, TOWNSHIP 23N, RANGE 5E, W.M. Delineation / Mitigation / Restoration / Habitat Creation / Permit Assistance 9505 19th Avenue S.E. Suite 106 Everett,Washington 98208 Phone: (425) 337-3174 Fax: (425) 337-3045 Email: mailbox@wetlandresources.com LEGEND MODIFIED BUFFER / SPLIT RAIL FENCE STREAM STANDARD BUFFER BUFFER IMPACT BUFFER ENHANCEMENT EXISTING GRAVEL NGPA SIGNS Date: 05.30.2024 SUNSET HIGHLANDS ADF Properties LLC Attn: Dale Fonk 15007 Woodinville-Redmond Rd, #A Woodinville, WA 98072 RENTON, WA Stream Study & Buffer Mitigation Plan Map Drawn by: JG WRI #: 24120 Sheet 2/2 Scale 1" = 40' 4020 60 800 HONEY CREEK TYPE F P R O P O S E D M E D IC A L B U IL D IN G P R O P O S E D P A R K IN G (D E T E N T IO N V A U L T B E L O W )PROPOSED BIORETENTION PONDS S U N S E T B L V D BUFFER ENHANCEMENT (4,460 SF) BUFFER IMPACT (3,928 SF)115'40' EXISTING GRAVEL (~24,580 SF) STORM OUTLET WITH OUTFALL PROTECTION