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HomeMy WebLinkAboutMEP2024-00027 BLD2024-01361 SFR - HMP Habitat Managment Plan - 10/31/2024 Habitat Management Plan Parcel: 32104-50-00045 71 E Country Club Dr East Union, WA 98592 Mason County Report prepared for: John Kilbourne 611 Yakima Ave S Tacoma, WA 98405 Prepared by: Rob Nagel PO Box 2466 Shelton, WA 98584 rob@arctos-environmental.com (360) 229-3118 Arc.+os Environmen+al LLG Project: 2024-H M P-015 October 2024 Project: 2024-HMP-015 October 2024 fkrctos Environmental LLG Table of Contents Overview ............................................................................................................1 PropertyDescription...........................................................................................2 Analysis of Potential Impacts..............................................................................3 MitigationMeasures...........................................................................................4 Monitoring..........................................................................................................8 Summary ............................................................................................................8 References..........................................................................................................9 Appendix: Site Photos.......................................................................................10 List of Figures Figure1: Vicinity Map .........................................................................................2 Figure2: Site Map...............................................................................................7 i Project: 2024-HMP-015 October 2024 lkrctos Environmental LLG Habitat Management Plan 32104-50-00045 71 E Country Club Dr East Union, WA 98592 Overview This report details a Habitat Management Plan (HMP) for the above referenced property in Mason County, Washington. The purpose of this report is to address potential adverse impacts from the construction of a proposed Single-Family Residence (SFR) within the regulated buffer of an Np stream. The SFR is proposed approximately 90ft from the Ordinary High-Water Mark (OHWM) of the stream at its closest point and this report proposed a reduced, variable buffer of 75ft-100ft. With the proposed reduced buffer, a total impact area of ±950ft2 is expected. Mitigation sequencing has been followed to avoid, minimize, and mitigate impacts to the buffer area. Mitigation measures have been designed to offset the potential impacts of constructing the SFR on the ecological functions and fish and wildlife habitat of the stream buffer. Measures include best-management practices for construction and planting a mitigation area of ±950ft' with native shrubs and ferns. The objectives of this report are as follows: • Identify potential impacts of the proposed development on the stream 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. 1 Project: 2024-HMP-015 October 2024 Arctos Environmental LLG �rMason County WA GIS I.Io- 13 © ' C. 0 Figure 1:Vicinity Map of project Property Description & Project Background The parcel is 0.55 acres in size and located in section 4 of Township 21 North, Range 3 West. The property slopes from the southeast to the northwest where an Np stream is located adjacent to the northwest corner of the lot. The stream was flowing during a site visit on 9-6-2024. The lot is well stocked with mature conifers and over stocked with sapling western hemlock (Tsuga heterophylla), which is inhibiting the growth of a diverse understory over a large portion of the property. The slope down to the stream is steep with a high amount of large woody debris. 2 Project: 2024-HMP-015 October 2024 Arctos Environmental LLG Analysis of Potential Impacts Vegetated buffers serve an important role in protecting critical public resources from adverse impacts associated with development, as well as providing fish and wildlife habitat. Below are the potential adverse impacts to ecological functions associated with the construction of the proposed SFR within the stream buffer. - Loss of fish and wildlife habitat The development area of the proposed project within the buffer is an estimated ±950ftz and located in areas on the property currently dominated by mature conifers and overstock western hemlock saplings. - Impervious surfaces Increasing impervious surfaces on a lot can increase the amount of storm water run-off and increase erosion potential. Mature trees will need to be removed in order to construct the SFR on this lot, but mitigation plantings will improve the remaining buffer's ability to filter sediment and nutrients from runoff from the property. No increased risk of erosion is anticipated if construction BMPs prescribed in this report are followed. - 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 project is located in a rural residential area where human noises are a daily occurrence. Also, no known nesting sites or individual occurrences of priority habitats and species have been identified near the project site. - Solar input Mature conifer trees will be removed in order to implement this project, however the remaining buffer between the house and stream is well stocked with mature trees. No significant change to the existing solar regime is anticipated. 3 Project: 2024-HMP-015 October 2024 Arc+os Environmental LLG 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 Given the lots small size, unique shape, and proximity to the stream, it is not possible to avoid impact by constructing the project outside of the buffer area. This plan proposes minimizing the impact to the stream buffer by keeping the development area modest and constructing the SFR as far from the stream as feasible. - 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 will be followed, including erecting silt fencing below the project area, and placing straw over any exposed areas until they are re-vegetated. Any equipment used will be checked daily for leaks and all fuel, lubricant, and chemicals will be stored off-site. - Clustering of development All activities related to this project will be clustered to the extent possible without impacting more of the buffer areas than necessary. Equipment and materials will be stored outside the buffer area when not immediately necessary for construction activities. - Mitigation area A mitigation area of approximately ±950ft' will be planted with native vegetation according to the planting guidelines below. Since the understory of the site is overstocked with western hemlock, which is inhibiting a healthy understory due to overshading, the mitigation area will be thinned of sapling western hemlock and planted with native shrubs, ferns, and groundcovers. The minimum number of native plants required to be installed in order to satisfy this requirement are as follows: 4 Project: 2024-HMP-015 October 2024 Pcrctos Environmental LLG o Shrubs: 38 o Ferns/groundcovers: 59 Planting Guidelines for the Mitigation Area Earthwork Machinery earthwork will be restricted to the minimum necessary to implement this plan; planting holes for specified vegetation installation will be hand dug. Native Plantings Native plantings will be installed within the mitigation area parallel to the edge of the stream to achieve the following minimum densities: Shrubs — ±5' on center Ferns/ground covers — ±4' on center The plan calls for thinning the sapling western hemlock to ±10ft centers within the mitigation area and installing single shrubs on ±5ft centers. The areas between the shrubs will be planted with ferns or groundcovers on ±4ft centers. Exact placement of installed materials will be up to the landscape installer, following the basic spacing pattern described above. Installed plants must be flagged to aid in monitoring visits. If any portion of the mitigation area is deemed unsuitable for planting either due to concerns of plant survivability or installer safety, then alternate mitigation areas must be determined by a qualified biologist and approved by Mason County. Native plants suitable for the mitigation area include, but are not limited to the following: Shrubs: Sala (Goultheria shallon) Oregon grape (Mahonia aquifolium) Vine maple (Acer circinatum) Evergreen huckleberry (Vaccinium ovatum) Beaked hazelnut (Corylus cornuta) 5 Project: 2024-HMP-015 October 2024 Arctos Environmental LLG Ferns/groundcovers: Western swordfern (Polystitchum munitum) Wild strawberry (Frogaria virginiona) 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 experienced landscapers familiar with planting native vegetation in natural settings. Installation will be performed during the first winter planting season after approval of this plan. Installed plants will be flagged to aid in monitoring requirements. Fertilizing Due to the proximity of the mitigation area to the critical area, NO fertilizer will be used during plant installation or maintenance. Maintenance Maintenance of the installations will be the responsibility of the property owner. Maintenance is to include any weeding or watering necessary to ensure plant survival for at least five years after the date of installation. 6 r Shelton,WA 98584 / PO Box 2466 QMI El It ....aa .......r. dF �: `i -. ® ems•i ••i0'i'Oi 0►'ii♦♦iii•�� � � �, E :- +i•�iia•Opi•••♦•iadi°i°i+.°i°i°i°i°i°•e - s,. / IL I Of This is not a survey map. must be field verified. ;'i •�, h;r„r_ . ., �i!•�.a�0i°a•!.!+!•!0 a°i♦ia♦ °i��l q Y+ I. f ..•gyp'. r 1• ��. f: to '� �.- ' !' �•;t .��� Project: 2024-HMP-015 October 2024 Arctos Environmental LLG Monitoring A baseline monitoring report will be submitted to the Mason County Planning Department when all construction is complete, and mitigation measures have been implemented. This initial report will establish photo points and document the location and general size of installed vegetation. An annual monitoring report will also be submitted to the county for 5 years to document the success of the mitigation area. If the survival rate of installed vegetation falls below 90% in the first two years, the area will be re-planted to meet the original target densities. The 90% threshold will be assessed annually at each monitoring visit and replanted the following planting season if required. After the first two years, a minimum visual plant cover area of 70% must be achieved within the mitigation area, or the area must be replanted to meet the 70% target. The reports will also include photos from the photo points established in the baseline monitoring report and document any occurrence of noxious weeds in the vicinity of the project site or mitigation area. Any noxious weeds observed will be removed. Summary This report details a Habitat Management Plan (HMP) for the above referenced Property in Mason County, Washington. The purpose of this report is to address potential adverse impacts from the proposed construction of a SFR with a total Impact footprint of ±950ft2 within the regulated buffer of a Type-Np stream. Mitigation measures have been designed to offset the potential impacts of constructing the project on the ecological functions and fish and wildlife habitat of the buffer area. Measures include best-management practices for construction and planting a ±950ft2 mitigation area with native vegetation in an area of the buffer currently lacking native vegetation in the understory. Proper implementation of this plan will result in no-net-loss of ecological function to the stream buffer from the development proposed by the applicant. 8 Project: 2024-HMP-015 October 2024 Arctos Environmental LLG References Guard,J. 1995. Wetland Plants of Oregon &Washington. Lone Pine Publishing. 240 pp. Edmonton, Alberta, Canada. Penttila, D. 2007. Marine Forage Fishes in Puget Sound. Puget Sound Nearshore Partnership Report No. 2007-03,Seattle,WA. 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/default/files/publications/00046/wdfw00046.pdf WDFW. 2001. Over-Water Structures: Freshwater Issues. 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:Hwdfw.wa.gov/sites/default/files/publications/00052/wdfw00052.pdf 9 Project: 2024-HMP-015 October 2024 Arctos Environmental LLG Appendix: Site Photos r#*• °�"�`- b ',4.y + a of �� 3 • .! .<- ���' � y�+s ?i wu- �. � `yYFx' � \•ter! s�.S�`,�°�i „�.,f ./1 ` i.A,, NN AV 4/�.�J?�[T,i7� Q J�,f], { /f'* / `�+is f�.t!�.�" '� ��'/�'►' .�y ���/���� F# 1,FA ��' '�l�'�i'� ,,K„ , �a �ry+i� � � ,t.r.'��.�„a.,y.-• �; �a � �� �s►rLl�`a► lr, � l _u'Q..�.lf�.�G'+H`4�Aeee�,1������lT:7d� v .....lil► �►�*:_ �'r_'h4ylz�t\w.:-''.�i Site Photo 1:Image showing a portion of the proposed mitigation area that is currently lacking a healthy and diverse understory of native plants due to the overshading of sapling western hemlock. 10