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HomeMy WebLinkAboutADV2022-00024 - BLD Letters / Memos - 3/11/2022 Habitat Management Plan Parcel# 32127-54-00075 & 32127-54-000/6 231 E Kilmarnock Rd Shelton, WA 98584 Mason County Report prepared for: Anthony Belgarcle 31420 8th PI SW Federal Way WA 98023 !- rn\ -r-1 i -1 r-1 r tJOV) l.Dl-LOiJ Prepared by: Rob Nagel FRQ F Philura Ln Shelton, WA 98584 arctosaerial@gmail.com (425) 344-9315 (360) 229-3118 ARCTOS A [ RIAE Environmental Consultation I Drone Imagery Project: 2021-H MP-008 P-008 May 2021 (Revised February 2022) ARCTOS Project: 2021-HMP-008 May 2021 (Revised February 2022) AERIAL Table of Contents Overview................................................................................................................1 PropertyDescription..............................................................................................2 Analysis of Potential Impacts.................................................................................3 MitigationMeasures..............................................................................................4 Monitoring .............................................................................................................9 Summary................................................................................................................9 References............................................................................................................10 List of Figures Figure1: Vicinity Map ............................................................................................2 Figure 2: Site Plan with drone imagery..................................................................8 i • A RCTOS Project: 2021-HMP-008 May 2021 (Revised February 2022) A I p I A L Habitat Management Plan 32127-54-00075 & 32127-54-00076 231 E Kilmarnock Rd Shelton, WA 98584 Overview This report details a Habitat Management Plan (HMP) for the above referenced properties in Mason County, Washington. The purpose of this report is to address any potential adverse impacts from constructing a Single-Family Residence (SFR) on each lot within the buffer of a Type-F stream. The Mason County Resource Ordinance (MCRO) requires a 150ft buffer with an additional 15ft building setback for Type-F streams. (see figure 1). However, the Resource Ordinance allows for a reduction in the buffer;setback if the lot was legally established prior to the effective date of the Resource Ordinance if it is the minimum necessary to allow reasonable use of the property. This report proposes a reduction in the stream buffer to an averaged 117.5ft with a range of 110ft-125ft. The SFRs are proposed as far from the ordinary high-water mark of the Type-F stream as possible. Mitigation measures have been designed to offset the potential impacts of these activities on the ecological functions of the stream buffer. Mitigation measures include construction BMPs, replanting the ±1,200ft2 drainfield areas with native L. L .J J A S ...- II + ... +�.�„ .-k.-. ;.- II UAJs ICE l ls, and gr ou lU lover s. nJ VVel! O s plat l 1 is I la IIVC si.JCLIC 111 a 1V111Ulttcu 1,900ft2 mitigation area for both lots. The objectives of this report are as follows: • Identify potential impacts of the construction of the proposed structure within the stream buffer, on the buffer's ecological functions and fish and wildlife habitat. • Determine mitigation measures that would offset those impacts and result in no net loss to ecological functions and fish and wildlife habitat within the remaining buffer. 1 ARCTOS Project: 2021-HMP-008 May 2021 (Revised February 2022) AERIAL © lalxiro jffJ/f � F Figure 1:Vicinity map of project. Property Description & Project Background The parcels are a combined 0.67 acres in size and located in the SE% of the SEX of section 27, Township 21 North, Range 3 West. The building sites are already cleared of vegetation from past management up to ±120ft of the stream. The SFR on one lot is proposed at ±130ft from the stream, while the other SFR is proposed outside the regulated 150ft buffer. Both houses are proposed 30ft from the public road, which is as close as allowed in the Lake Limerick Community. Past grading on both lots has made the only suitable drainfield locations to be ±100ft from the stream. Both drainfield locations will need to be cleared of native vegetation and are within the stream buffer. The areas cleared will be replanted with native shrubs, ferns, and ground covers after installation of the drainfield components. III is INlasoni Coui my r esuuI LC Vrdi Idf ce requires a 150ft buffer with an additional 15ft structure setback, which encompasses most of the subject properties. This report proposes a reduction of the regulated buffer to 100ft with an additional 15ft structure setback. This buffer reduction is the minimum necessary to afford the property owner with a reasonable use of the lot. The proposed buffer reduction is also compatible with the character of surrounding permitted uses and would not adversely affect traffic circulation. A RCTQS Project: 2021-HMP-008 May 2021 (Revised February 2022) A[RI AL Analysis of Potential Impacts Vegetated buffers serve an important role in protecting critical public resources, as well as fish and wildlife habitat from adverse impacts associated with development. Below are the potential adverse impacts to ecological functions associated with the construction of these proposed structures within the stream buffer. - Increased storm-water runoff and erosion impervious surfaces such as roofs and driveways contribute to increased flow of runoff during storm events. This increased flow could contribute to erosion and increased sediment reaching the stream without a proper storm water management plan. Only ±700ft2 of the proposed structures are within the regulated buffer. Construction BMPs have been proposed in the "Mitigation Measures" section of this report below and no significant increase in storm-water runoff is anticipated from these projects. - Stream bank de-stabilization Removal of buffer vegetation and increasing storm water run-off can speed erosion of streambanks and make them unstable. All areas where vegetation removal is proposed will be replanted and straw will be placed over any areas while they are exposed. No increased risk of erosion is anticipated. - Loss of wildlife habitat The total development footprint from these projects within the buffer is ±3,100ft 2. Mitigation measures include replanting a total of 4,300ft2 with native vegetation, which will increase the amount of wildlife habitat adjacent to the building sites and have a net ecological benefit to the stream buffer. - Increased disturbance from noise pollution A temporary increase in noise from construction activities is likely to occur. but activities will be limited to daylight hours, and the projects are located in an area along the stream where human noises are a common 3 A RCTOS Project: 2021-HMP-008 May 2021 (Revised February 2022) A [RI A occurrence. Also, no known nesting sites or individual occurrences of pr iori-y habitats and species have been identified near the pl oject sites. - Increased Solar input The proposed structures are sited in an area with mature conifers that will be left to shade the stream. Native plantings within the mitigation area will benefit the stream by increasing shade and reducing solar input in the long- term. Mitigation Measures To avoid, minimize, and mitigate for the potential adverse impacts identified above, the following have been identified as appropriate measures for this project: - Minimizing/avoiding impact The proposed projects minimize the impact to the stream buffer by limiting the square footage of the structures within the buffer to ±700ft2 and placing them as far from the stream as feasible. The structures will be constructed in an area already devoid of vegetation. - Best Management Practices for construction Construction activities related to this project will be restricted to favorable weather conditions and best management practices for reducing disturbance and erosion will be followed, including placing straw over exposed areas, and erecting silt fencing below the project area. Equipment will, be checked daily for leaks and all fuel, lubricant, and chemicals will be stored outside the stream buffer. - Clustering of development All activities related to these projects will be clustered to the extent possible without impacting more of the stream buffer than necessary. Equipment and materials will be parked/stored outside the stream buffer whenever not in use. A RCTOS Project: 2021-HMP-008 May 2021 (Revised February 2022) A[f'4[ - Removal of invasive species All occurrences of noxious weed species observed in the vicinity of the project site and mitigation area will be mechanically removed without the use of chemical herbicides. - Stream buffer re-vegetation A mitigation area of 1,900ft2 plus ±2,400ft2 of drainfield area will be restored with native riparian vegetation through plantings per the planting guidelines described below. The mitigation area to be replanted is an area between the proposed structures, along the lot line between the two properties. The minimum number of trees, shrubs, and ferns/groundcovers to be planted in the 1,900ft2 mitigation area in order to meet the required densities are as follows: -Trees = 18 -Shrubs = 55 -Ferns/groundcovers = 115 Once the mitigation area is established, the lot owners must allow the planted vegetation to grow to the full mature size of the species selected, without pruning or trimming. The mitigation area must also be treated as if part of the regulated stream buffer indefinitely. The area cleared for the drainfields will be replanted with shrubs, ferns, and ground covers after installation of the drainfield components. The minimum number of shrubs, ferns, and groundcovers to be planted in the ±2,400ft2 of area cleared for the drainfields in order to meet the required densities are as follows: -Ferns/groundcovers = 150 Any additional landscaping within the stream buffer is required to consist of native plant species typically found in undisturbed riparian areas. Species selected should include common riparian vegetation not 5 ARCTOS Project: 2021-HMP-008 May 2021 (Revised February 2022) A [p I A currently on the property which will result in a net increase in species r iChn�ess and biodiver sitji within the buffer Planting Guidelines for the Mitigation Area Earthwork Machinery earthwork will be restricted to the minimum necessary in order to implement this plan; planting holes for specified vegetation installation will be hand dug. Native Plantings Kluti`„Ie pluntinbc ��,iII he inctullerrl LArithin the mitigatien urea r ruIIeI to the `nrlc c of the buffer to achieve the following minimum densities: Trees — 10' on center Shrubs — 5' on center Ferns, grasses, and ground-covers -4' on center The plan calls for installing single trees on 10ft centers and single shrubs on 5ft centers. Areas between will be filled in with ferns, grasses, or ground-covers on 4ft centers. The entire mitigation area should be mulched to prevent any non- native species from establishing within the mitigation area. Exact placement of installed materials will be up to the landscape installer, following the basic 10-foot spacing pattern described above. Volunteer native vegetation can be counted towards the target densities of restoration area at the time of monitoring audits. Native plant species appropriate for the mitigation area include the following: Trees: Western red cedar (Thuja plicata) Douglas fir (Pseudotsuga menziesii) Garry oak (Quercus garryana) Western hemlock (Tsuga heterophylla) Grand fir (Abies grandis) Cascara (Rharnnus purshiana) Pacific crabapple (Malus.fusca) 6 A RCTQS Project: 2021-HM P-008 May 2021 (Revised February 2022) A[R I A L Serviceberry (Almenlanchier alnifolia) Shrubs: Ocean spray (Hoiodigcu≤ di. color) Thimbleberry (Rubus parviflorus) Tall Oregon grape (Mahonia aquifolium) Nootka rose (Rosa nutkana) Salal (Gaultheria shallon) Evergreen huckleberry (Vaccinium ovatum) Snowberry (Symphorocarpus albus) Ferns, grasses, and ground-covers: Sword fern (Polystichum munitum) Bracken fern (Pteridium aquilinum) Tufted hairgrass (Deschampsia cespitosa) All planting should occur during winter dormancy. The optimum time for planting is from November to March. Installation Installation of the prescribed vegetation will be performed by qualified landscapers familiar with planting of native vegetation in natural settings. Installation will be performed only after construction on the property is completed to avoid damage to the plantings. Fertilizing Due to the proximity of the mitigation area to the Hood Canal, NO fertilizer will be used during plant installation or maintenance. Maintenance Maintenance of the installations will be the responsibility of the landscape installer. Maintenance is to include any weeding or watering necessary to ensure plant survival for up to three years after the date of installation. 7 00 �/� GOD j m Q1 N m Z tp N tr8S86 VM'uoflayS o N M t� ° - E-2 NI)pauiewl!)i 3 LE? 9L000-bS-LZ LZE Z� 0 mo o N'v 78 SL000 try LZLZE#la»pd w >,- A. v a= d c v Q v '^ dew f'S' jejuaWUOJInu3 axis C a� ai v Q Y �L� ter-- •yrt�. ,. ..,i e 2 InNE NN p:,.y N W d � v G7 d x e + 3 -•Y E• o- n` tp T a. N !, O eN a. A RCTOS Project: 2021-HMP-008 May 2021 (Revised February 2022) A[n 1AE. Monitoring Following the implementation of the mitigation measures, an annual report will be submitted to the county for J years post construction. The report will detail the presence of new, or the reoccurrence of any invasive species. Invasive species found on site will again be removed mechanically, using hand tools only to reduce disturbance to the shoreline buffer. The annual report will also document the planting success of the mitigation area. If planting survival in the mitigation area falls below 90% in the first three years after installation. The area will be re- planted to meet the target densities. If any failures of mitigation measures are identified during the annual inspection, corrective actions will be recommended in the report and will be taken by the property owner to restore them to working order as soon as possible. Summary This report Identifies potential impacts of the construction of two proposed SFRs, with a combined square footage of±700ft2 footprint within a regulated Type-F stream buffer. The proposed building sites are currently devoid of vegetation and provide little benefit to the stream and its buffer. A total of 2,400ft2 within the regulated buffer will need to be cleared for the drainfields of these two SFRs. Mitigation measures have been proposed to avoid, minimize, and mitigate for those impacts identified on the stream buffer's ecological functions and fish and iI.1I;c1 I,n l+n+ C.uccessf,ui mr+inrv.n�n+-,+ nn of thn nv.-fine n,4 '+ n-,tinr rn. vvnunic ..cau.LcL. .Ju _ I _lI 1111 ciiiciiLaL1 %J UIc N1 V%J u IIIIL;5c LIU11 tiicaiui c) will result in no net loss to the stream and its buffer's ecological functions, structural diversity, and species richness. Mitigation measures include construction BMrs, re-establishing native vegetation in a 1,900ft2 mitigation area, and replanting the 2,400ft2 drainfield areas after installation of the drainfield components. 9 ARCTOS Project: 2021-HMP-008 May 2021 (Revised February 2022) AERIAL References Guard,J. (1995). Wetland Plants of Oregon &Washington. Lone Pine Publishing.240 pp. Edmonton, Alberta, Canada. Pojar,J. and A.MacKinnon. 1994.Plants of the Pacific Northwest Coast (Revised Edition 2014). Lone Pine Publishing. 528 pp.Vancouver, British Columbia, Canada. WDFW. 2002. Integrated streambank protection guidelines. Washington Department of Fish and Wildlife, Washington Department of Transportation, and Washington Department of Ecology. Posted on Washington Department of Fish and Wildlife web site: https://wdfw.wa.gov/sites/defa ult/files/pubi ications/000461wdfw00046.pdf 10