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HomeMy WebLinkAboutAPPROVED Att B Wetlands memo 5.21.2024Attachment B – Wetlands Memorandum horsleywitten.com Memorandum TO: Amanda Lima and Nathan Whetten, Town of Yarmouth April Wobst and Jordan Mora, APCC FROM: Ben Wollman, Wetland Scientist DATE: May 21, 2024 RE: Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA HW has prepared the following memo and attached site figures to document the jurisdictional wetland resource areas and to provide regulatory context for future work on stormwater improvement projects in the Town of Yarmouth, MA. Potential retrofit locations were selected based upon targeted watersheds surrounding impaired waters in the Town1. This memo includes details on jurisdictional resource areas at the following site locations: • Baker Ave (MC-5) • Grove Street (HIH-3) • Standish Way (MC-3) • Buck Island Road & Lake Road West (PR-3 & PR-4) • Curve Hill Road (UBR-4) Below, we describe the sites generally, and then include specifics regarding wetland resource areas for each site. General Site Descriptions Each of these sites is located in the southern part of Yarmouth, south of Route 6, and west of the Bass River. Figures 1 and 2 (attached) and Image 1 below depicts the location of all sites relative to one another. Figures 4 through 6 provide additional information for each site, including soils information, but are not discussed. Geographically, Sites MC-5, HIH-3, and MC-3 are located in close proximity in West Yarmouth near the Barnstable town boundary and within the Mill River/Lewis Bay watershed. Sites PR-3 and PR-4, located near Buck Island Road, north of Route 28, are located within the Swan Pond/Parker River watershed. Site UBR-4 is in the eastern part of Yarmouth, near the town boundary with Dennis within the Bass River watershed. Site-specific figures with detailed resource area 1MassDEP. 2023. Final Massachusetts Integrated List of Waters for the Clean Water Act 2022 Reporting Cycle. CN 568.1, Massachusetts Department of Environmental Protection, Bureau of Water Resources, Division of Watershed Management, Watershed Planning Program. Worcester, MA (available at https://www.mass.gov/lists/integrated- lists-of-waters-related-reports). Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 2 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx information (Figure 4) are provided for each site, grouping only sites PR-3 and PR-4. Collectively, these sites represent six of the top ten sites identified for potential stormwater retrofit sites in Yarmouth. Image 1. Locations of sites evaluated as part of the Yarmouth Stormwater Retrofit Assessment. Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 3 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Wetland Resource Areas The six sites support a number of coastal and/or freshwater wetland resource areas, as defined under the Massachusetts Wetlands Protection Act (M.G.L. Ch. 131 § 40) and the Town of Yarmouth Wetlands Protection By-law (Chapter 143) and their respective regulations. Resource areas occurring at or near these project sites collectively include the following, although not all resource areas are located at all sites. Descriptions of the resource areas at each site is provided in the Site Specific Conditions section below. • Coastal Bank; • Coastal Dune; • Coastal Beach/Tidal Flat; • Salt Marsh; • Bank (Inland); • Bordering Vegetated Wetland (BVW)/Vegetated Wetland; • Riverfront Area; and • Land Subject to Coastal Storm Flowage (LSCSF). Jurisdictional buffer zone areas at the sites include the 35-foot, 50-foot, and 100-foot Buffer Zones to Coastal Bank, Coastal Dune, Coastal Beach, Salt Marsh, and Bank (Inland). Additional jurisdictional areas identified adjacent to the sites include Land Under the Ocean, Land Containing Shellfish, and Land Under Waterbodies and Waterways. Several of the sites also fall within a Coastal Watershed Area, as defined by the Yarmouth Wetland Regulations; however, anticipated activities would not include any of the land use practices prohibited under Section 4.11(1)(b)(1-6). Resource Area Delineation Methodology On November 28 and December 5, 2023, Horsley Witten Group, Inc. (HW) wetland biologists identified and delineated the above-listed wetland resource areas. HW followed wetland resource area identification and on-site delineation procedure guidelines described in the Massachusetts Department of Environmental Protection (MassDEP) handbook, entitled Massachusetts Handbook for Delineating Bordering Vegetated Wetlands (September 2022), Massachusetts Wetlands Protection Act (M.G.L. Ch. 131 § 40), and its implementing Regulations (310 CMR 10.00), and the Town of Yarmouth Wetlands Protection By-law (Chapter 143) and associated Town of Yarmouth Wetland Protection Regulations. Additionally, State Coastal Bank determinations were made following the MassDEP Program Policy 92-1: Coastal Banks (March 1992). Prior to conducting field delineations, HW reviewed existing source data, including USGS Geological Survey 7.5 minute topographic maps, MassDEP wetlands source data available through the Massachusetts Geographic Information System (MassGIS), USDA Natural Resources Conservation Service (NRCS) soils survey, U.S. Fish and Wildlife Service National Wetland Inventory (NWI) maps, and other source data to identify the presence of jurisdictional wetlands and waters of the United States within the site. This information was used to compile base mapping to assist in the understanding of the hydrologic variables, soils conditions, and vegetation communities (where applicable). Resource area boundaries are shown on the existing conditions plans. The Figure 4 series depicts the limits of the wetland resource areas as shown on MassDEP GIS Wetlands data. Regulatory definitions of the resource areas are provided below. Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 4 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Resource Area Regulatory Definitions Coastal Bank is defined at 310 CMR 10.30(2) as “the seaward face or side of any elevated landform, other than a coastal dune, which lies at the landward edge of a coastal beach, land subject to tidal action, or other wetland.” Coastal Bank is defined by at 2.05(2) of the Yarmouth Wetland Protection Regulations as “the seaward face or side of any elevated landform, other than a coastal dune, which lies at the landward edge of a coastal beach, land subject to tidal action or storm flowage, or other wetland. Any minor discontinuity of the slope notwithstanding, the top of the bank shall be the first significant break in slope that occurs above the relevant 100 year flood plain elevation.” Coastal Dune is defined at 310 CMR 10.28(2) as “any natural hill, mound or ridge of sediment landward of a coastal beach deposited by wind action or storm overwash. Coastal dune also means sediment deposited by artificial means and serving the purpose of storm damage prevention or flood control.” The Yarmouth Wetland Protection Regulations define coastal dune similarly. Coastal Beach is defined at 310 CMR 10.27(2) as “unconsolidated sediment subject to wave, tidal and coastal storm action which forms the gently sloping shore of a body of salt water and includes tidal flats. Coastal beaches extend from the mean low water line landward to the dune line, coastal bank line or the seaward edge of existing man-made structures, when these structures replace one of the above lines, whichever is closest to the ocean.” The Yarmouth Wetland Protection Regulations definition of coastal beach is the same as the above. Tidal Flat means any nearly level part of a coastal beach which usually extends from the mean low water line landward to the more steeply sloping face of the coastal beach or which may be separated from the beach by land under the ocean. Salt Marsh is defined at 310 CMR 10.32(2) as “a coastal wetland that extends landward up to the highest high tide line, that is, the highest spring tide of the year, and is characterized by plants that are well adapted to or prefer living in, saline soils. Dominant plants within salt marshes are salt meadow cord grass (Spartina patens) and/or saltmarsh cordgrass (Spartina alterniflora). A salt marsh may contain tidal creeks, ditches and pools.” The Yarmouth Wetland Protection Regulations definition of salt marsh is the same as the above. Bank is defined at 310 CMR 10.54(2)(a) as “…the portion of land surface which normally abuts and confines a water body. It occurs between a water body and a vegetated bordering wetland and adjacent floodplain, or, in the absence of these, it occurs between a water body and an upland. A Bank may be partially or totally vegetated, or it may be comprised of exposed soil, gravel or stone. The upper boundary of a Bank is first observable break in the slope or the mean annual flood level, whichever is lower. The lower boundary of a Bank is the mean annual low flow level” [310 CMR 10.54(2)(c)]. The Yarmouth Wetland Protection Regulations define Bank similarly to the above; however, the upper boundary of the Bank is defined under the Yarmouth Wetland Protection Regulations as “the first break in slope above the mean annual flood level” [3.01(2)]. Bordering Vegetated Wetlands (BVWs) are defined under Massachusetts WPA Regulations at 310 CMR 10.55(2)(a) as “freshwater wetlands that border on creeks, rivers, streams, ponds and lakes. The types of freshwater wetlands are wet meadows, marshes, swamps and bogs. Bordering Vegetated Wetlands are Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 5 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx areas where the soils are saturated and/or inundated such that they support a predominance of wetland indicator plants. The boundary of Bordering Vegetated Wetland is defined at 310 CMR 10.55 (2)(c) as the line within which 50% or more of the vegetational community consists of wetland indicator plants and saturated or inundated conditions exist.” The Yarmouth Wetland Protection Regulations define Vegetated Wetlands [3.02(2)] as follows: “Vegetated wetlands are brackish and freshwater wetlands. The types of brackish and freshwater wetland are wet meadows, marshes, swamps and bogs. They are areas where the topography is low and flat, and where soils are annually saturated. The ground and surface water regime and the vegetational community which occur in each type of freshwater wetland are specified in section 3.02, (2), (c).” “The boundary of a vegetated wetland is the line within which 50% or more of vegetational community consists of the wetland plant species identified in sections 3.02, (1) thru 3.02, (2), (c), (4), below. A minimum size of 3000 square feet is required for jurisdiction under these regulations.” Riverfront Area is defined at 310 CMR 10.58(2)(a) as “the area of land between a river’s mean annual high water (MAHW) line and a parallel line measured horizontally. The Riverfront Area may include or overlap other resource areas or their buffer zones. The Riverfront Area does not have a buffer zone.” And more specifically at 310 CMR 10.58(2)(a)3 as “the area of land between a river's MAHW line measured horizontally outward from the river and a parallel line located 200 feet away.” The mean annual high water (MAHW) line of a river is defined at 310 CMR 10.58(2)(a)2 as “the line that is apparent from visible markings or changes in the character of soils or vegetation due to the prolonged presence of water and that distinguishes between predominantly aquatic and predominantly terrestrial land (…) c. In tidal rivers, the mean annual high-water line is coincident with the mean high water line determined under 310 CMR 10.23: Mean High Water Line means the line where the arithmetic mean of the high water heights observed over a specific 19-year metonic cycle (the National Tidal Datum Epoch) meets the shore and shall be determined using hydrographic survey data of the National Ocean Survey of the U.S. Department of Commerce.” Land Subject to Coastal Storm Flowage is defined at 310 CMR 10.04 as “land subject to any inundation caused by coastal storms up to and including that caused by the 100-year storm, surge of record or storm of record, which ever is greater.” State-Listed Rare Species Habitat and Open Space According to the most recent version of the Massachusetts Natural Heritage Atlas (15th Edition, August 1, 2021), none of the sites fall within areas of Estimated Habitat of Rare Wildlife and Certified Vernal Pools or Priority Habitat of Rare Species as designated by the Massachusetts Natural Heritage and Endangered Species Program (NHESP)(see Figures 4a through 4e). Invasive Species Wherever present, HW noted the presence of invasive plant species for future reference. Invasive or Likely Invasive species (as defined by the Massachusetts Invasive Plant Advisory Group or MIPAG) were present at varying densities within jurisdictional wetland areas at or adjacent to most of sites described Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 6 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx in this report. Details of the species and densities observed are provided for each site under the Site Specific Conditions section. MIPAG identifies invasive plant species as “non-native species that have spread into native or minimally managed plant systems in Massachusetts,” and which “cause economic or environmental harm by developing self-sustaining populations and becoming dominant and/or disruptive to those systems.” For future planning purposes, the Town may wish to develop a management plan for reducing or eliminating these plants at one or more of these sites to allow for the establishment of naturally vegetated protective buffers to the wetland resource areas. Site -Specific Conditions Baker Ave (MC-5) The Baker Ave site (MC-5) is located at the east end of Baker Ave. The site is bordered by a vegetated slope that descends toward Mill Pond to the east with residential properties to the north and south. FEMA Designation The Baker Ave site is located within Special Flood Hazard Area, Zone AE (1% annual chance of flooding, base flood elevation 11 feet) and Other Areas of Flood Hazard, Zone X (0.2% annual chance of flooding with average depth less than one foot or with drainage areas less than one square mile) (Community Panel No. 25001C0567J, effective July 16, 2014)(Figures 3a and 3a-1). Resource Areas Resource areas located at or adjacent to this site include Inland Bank, Coastal Bank, and LSCSF as described below. Figure 4a depicts the resource areas as shown in MassGIS data layers. Site specific resource areas are as follows. An Inland Bank is present to the east of the site, along the edge of Mill Pond (Photo 1). The Bank is vegetated with marsh species along the lower reaches and transitions to a mix of trees, shrubs, and vines near the upper boundary. The upper boundary of the Bank occurs where there is break in slope after a short steep rise from the edge of the water. Vegetation growing along the Bank includes species such as gray willow (Salix cinerea), alder (Alnus sp.), blackberry (Rubus sp.), multiflora rose (Rosa multiflora), round-leaf greenbrier (Smilax rotundifolia), rough-stem goldenrod (Solidago rugosa), sensitive fern (Onoclea sensibilis), cattail (Typha sp.), purple loosestrife (Lythrum salicaria), and sedges (Carex spp.). Species observed growing directly upslope of the Bank area include pitch pine (Pinus rigida), black cherry (Prunus serotina), American holly (Ilex opaca), staghorn sumac (Rhus typhina), blackberry, multiflora rose, shrub honeysuckle (Lonicera sp.), round-leaf greenbrier, and Asian bittersweet (Celastrus orbiculatus). The upper boundary of the Bank was delineated with a series of consecutive blue flagging stations labeled BANK 100 through BANK 102. The Baker Ave site is also located within a MassDEP Approve Zone II (Figure 5a). Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 7 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Photo 1. Inland Bank at the edge of Mill Pond (facing south), east of the Baker Ave site (December 2023). A Coastal Bank is also present at the site where the slope rises from Mill Pond toward the east end of Baker Ave. To determine the regulatory limits of the Coastal Bank, elevation data was collected with Total Station and GPS survey units along four transects (T1 – T4) perpendicular to the topography between the pond’s edge and the 100-year flood elevation in accordance with the MassDEP Program Policy (92-1) to determine the top of the Coastal Bank. The site is within LSCSF (Zone AE, el. 11 feet) and the upper boundary of the Coastal Bank occurs primarily at the 100-year storm elevation where the slope grade falls between 10-25%, conforming to Figure 3 of the MassDEP Wetlands Program Policy 92- 1; however, there is also a small section where the upper boundary of the Coastal Bank occurs at the point where the grade becomes less than 10% below the 100-year storm elevation, conforming to Figure 4 of Policy 92-1. The Coastal Bank is primarily vegetated with a mix of trees, shrubs, and vines, which include pitch pine (Pinus rigida), black cherry (Prunus serotina), American holly (Ilex opaca), staghorn sumac (Rhus typhina), blackberry, multiflora rose, shrub honeysuckle (Lonicera sp.), round-leaf greenbrier, and Asian bittersweet (Celastrus orbiculatus) (Photo 2). Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 8 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Photo 2. View of the Coastal Bank, facing southeast from Baker Ave at the Baker Ave site (December 2023). LSCSF at this site comprised of the vegetated slope between the east end of Baker Ave and Mills Pond, where the Coastal Bank and Inland Bank are present. The boundary of LSCSF coincides with the FEMA Floodzone AE (el. 11) boundary, as shown on Figure 3a-1. Invasive Species Invasive plant species were observed to be present in relatively high densities on the Inland Bank and/or Coastal Bank at the Baker Ave site. Species observed include gray willow, shrub honeysuckle, multiflora rose, Asian bittersweet, and purple loosestrife. Grove Street (HIH-3) The Grove Street site (HIH-3) is located at the southern end of Grove Street, at the northwest side of Lewis Bay, where there is public access to Grove Street Beach (Photo 3). The project is proposed within the ROW of Grove Street at the beach access point. The site is bordered by residential properties to the east and west. FEMA Designation The Grove Street site is located within Special Flood Hazard Areas, Zone VE (1% annual chance of flooding, base flood elevation 13 feet) and Zone AE (1% annual chance of flooding, base flood elevation 11 feet) (Community Panel No. 25001C0569J, effective July 16, 2014) (Figures 3a and 3a-2). Resource Areas Resource areas located at or adjacent to this site include Salt Marsh, Coastal Beach, Coastal Dune, Riverfront Area, and LSCSF (Photo 4)(Figure 4b). Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 9 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Photo 3. Coastal Resource Areas at the Grove Street site, looking southwest from the end of Grove Street (November 2023). Photo 4. View of the Coastal Resource Areas at the Grove St site, looking north from the path through the Salt Marsh (November 2023). Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 10 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx As seen in Photo 5, Salt Marsh is present to the south of the proposed project site, which extends further to the east along the southern end of the 9 Vernon Street property, as well as to the northwest along both sides of an unnamed perennial tidal stream the flows north to south into Lewis Bay through the 8 Grove Street and 2 Highland Street properties west of Grove Street. A small 1-2 foot wide walking path cuts through the Salt Marsh south of Grove Street, providing further access to a larger beach area south of the Salt Marsh. Common species observed within the Salt Marsh include saltmarsh cordgrass (Spartina alterniflora), saltmeadow cordgrass (Spartina patens), maritime marsh-elder (Iva frutescens), and seaside goldenrod (Solidago sempervirens). HW delineated the upper boundary of Salt Marsh with a line of two pink pin flag stations labeled SM 1 to SM 2. Photo 5. Salt Marsh directly south of the Grove Street site, looking west from path (November 2023). A small section of Coastal Beach is present just north of the Salt Marsh at the Grove Street site, where the Salt Marsh vegetation transitions to coarse, unconsolidated sand with some scattered pebbles and mollusk shells (Photo 6). A wrack line was observed along the mean high tide line at the time of the site visit. HW delineated the upper boundary of Coastal Beach along the wrack line with a line of orange pin flag stations labeled BEACH 1 to BEACH 2. The Coastal Beach transitions to Coastal Dune just upgradient (north) of the Coastal Beach. Additionally, a Tidal Flat area is present to the southwest of the Salt Marsh adjacent to Grove Steet, where the water from the unnamed stream meets and flows through/past the outer Coastal Beach area into Lewis Bay (Photo 6). At high tide, the Tidal Flat area is a pool of standing water. The closest section of the Tidal Flat area is further from the proposed project site than the small section of Beach north of the Salt Marsh, and so was not delineated during the site visit. Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 11 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Photo 6. Section of Coastal Beach present at the Grove St site between Salt Marsh and Coastal Dune looking east toward the 9 Vernon St property (November 2023). Coastal Dune is present between the proposed project site and the Coastal Beach area, where the slope rises 1-2 feet from the beach to meet the end of the Grove Street pavement. The dune extends to the west onto the 8 Grove Street property, where it is confined by Salt Marsh along the unnamed stream to the west and a retaining wall running northwest on the property. The dune also extends further to the east onto the 9 Vernon Street property and is confined by the lawn and landscaped areas of the residential properties on this side of Grove Street. The dune section at the end of Grove Street is comprised of smoother, unconsolidated aeolian (wind-borne) sediments and is densely vegetated with a mix of beachgrass (Ammophila breviligulata), beach rose (Rosa rugosa), and seaside goldenrod in some areas, while remaining mostly unvegetated in other areas. The Coastal Dune then transitions to the pavement at the end of Grove Street, as well a dense tangle of primarily non-native multiflora rose, privet, beach rose, and Asian bittersweet along the east and west sides of the Grove Street ROW (Photo 7). HW delineated the landward boundary of the Coastal Dune with a line of two blue flagging stations labeled DUNE 1 to DUNE 2. Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 12 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Photo 7. Coastal Dune is present at the Grove Street site looking northeast from the Coastal Beach. Wrack line represents the transition between Coastal Beach and Coastal Dune (November 2023) Riverfront Area is present at the site, associated with the unnamed tidally influenced stream that flows into Lewis Bay to the west of Grove Street. The Riverfront Area extends landward 200 feet from the Mean High Water (MHW) Line of the unnamed stream (Image 2). The MHW elevation was determined using Lidar elevation data from MassGIS in combination with hydrographic survey data from a nearby National Oceanic and Atmospheric Administration (NOAA) tidal station located in Chatham, MA (Station ID - 8447435). Based on this data, the Riverfront Area is present over land areas between elevation 2.31’ (NAVD88) and a parallel line that is extended 200 feet horizontally (landward) from this elevation contour, encompassing the project site and overlapping with Coastal Dune, LSCSF, and the buffer zones to Coastal Marsh, Coastal Beach, and Coastal Dune (Photo 8). Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 13 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Image 2. Aerial excerpt from MassMapper (MassGIS 2021) with labels added to show the tidal stream in relationship to the Grove Street site. Photo 8. Looking northwest toward the tidally influenced stream from the southeastern corner of the 8 Grove Street property (November 2023). Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 14 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx LSCSF encompasses the entire site. The boundary of LSCSF coincides with the FEMA Floodzone AE (el. 11) boundary, as shown on Figures 3a and 3a-2. Invasive Species Invasive plant species were observed to be present in relatively high densities within the upper section of the Coastal Dune and further upgradient along the edges of the Grove Street ROW at the Grove Street site. Species observed include multiflora rose and Asian bittersweet. Standish Way (MC-3) The Standish Way site (MC-3) is located along the southern end of Standish Way, at the north-central side of Lewis Bay, with project elements proposed within the Standish Way ROW between Windemere Road and Brewster Road. The Standish Way ROW is primarily bordered by residential properties in the vicinity of the proposed project with the exception of the Colonial Acres Resort located on the east side of Standish Way between Sagamore Road and Windemere Road. Southwest of the intersection between Standish Way and Windemere Road is a public parking area providing access to the Colonial Acres Beach. FEMA Designation The Standish Way site is located within Special Flood Hazard Area, Zone AE (1% annual chance of flooding, base flood elevations 11 & 12 feet) and Other Areas of Flood Hazard, Zone X (0.2% annual chance of flooding with average depth less than one foot or with drainage areas less than one square mile) (Community Panel No. 25001C0569J, effective July 16, 2014) (Figures 3a and 3a-3). Resource Areas Resource areas located at or adjacent to this site include Salt Marsh, Riverfront Area, and LSCSF (Figure 4c). Salt Marsh is present at the southern end of Standish Way, around the perimeter of the public parking area (Photo 9). Adjacent to the parking area’s southern and western edges is a section of mowed grass and a few small upland trees and shrubs before transitioning to Salt Marsh along the outer edge of this maintained landscape strip. The Salt Marsh extends along the western edge of the mowed grass area and is bisected by a dirt driveway that extends to the west from the parking area, before connecting to a revetment-protected sand access way that heads south along the western end of Colonial Acres Beach. The Salt Marsh picks up again on the north side of the dirt path northwest of the parking area and extends north briefly, before transitioning to mowed lawn at the 17 Pilgrim Road property (Photo 10). The transitional edge between Salt Marsh and mowed lawn area carries to the northwest, away from the proposed project site, near the southwest corner of the 127 Standish Way property. Common species observed within the Salt Marsh include saltmarsh cordgrass, saltmeadow cordgrass, maritime marsh-elder, and eastern false willow (Baccharis halimifolia). HW delineated the landward boundary of Salt Marsh with a series of consecutive blue flagging stations labeled SM 100 through SM 110. Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 15 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Photo 9. View of the Salt Marsh present along the southern perimeter of the parking area at the Standish Way site, looking west from the southern end of Standish Way (November 2023). Photo 10. View (looking northwest) towards the Salt Marsh transition to mowed lawn at the southwest corner of the 127 Standish Way property (November 2023). Riverfront Area is present at the southern end of the site, associated with the unnamed tidally influenced stream that flows east to west along the north side of the Colonial Acres Beach. The Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 16 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx stream flows into Lewis Bay through a culvert at the west side Colonial Acres Beach, beneath the revetment-protected access path that leads out to the beach from the parking area (Image 3 and Photo 11). The Riverfront Area extends landward 200 feet from the Mean High Water (MHW) Line of the unnamed stream and encompasses portions of the project site between Pilgrim Road and Windemere Road, and overlapping with LSCSF, and the buffer zones to Coastal Marsh. The MHW elevation was determined using LiDAR elevation data from MassGIS in combination with hydrographic survey data from a nearby NOAA tidal station located in Chatham, MA (Station ID - 8447435). Based on this data, the Riverfront Area is present over land areas between elevation 2.31’ (NAVD88) and a parallel line that is extended 200 feet horizontally (landward) from this elevation contour, encompassing portions of the project site between Pilgrim Road and Windemere Road, and overlapping with LSCSF, and the buffer zones to Coastal Marsh. Image 3. Aerial excerpt from MassMapper (MassGIS 2021) with labels added to show the tidally influenced stream in relationship to the Standish Way site. Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 17 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Photo 11. View looking south from the parking area toward at the boardwalk that spans the tidal stream at the southern end of Standish Way (December 2023). LSCSF encompasses all site areas below el. 11’ (NAVD88), which is the landward boundary of the FEMA AE Floodzone, as shown on Figure 3b and 3b-1. Invasive Species Invasive plant species were observed to be present in relatively low densities near the upper boundary of the Salt Marsh around the parking area at the south end of Standish Way. Species observed include Asian bittersweet and common reed (Phragmites australis). Buck Island Road (PR-3) & Lake Road West (PR-4) The Buck Island Road and Lake Road W sites (PR-3 & PR-4) are comprised of two locations with unique stormwater management practices being proposed at each location; however, they are being presented as one combined site due to their close proximity. The Buck Island Road section is located at the Town- owned 19 Lake Road West property, northwest of the intersection between Buck Island Road and Lake Road West and is bordered by Buck Island Road to the south, Lake Road West to the north/east, and residential properties to the west. The Lake Road West section is located within the ROW at the intersection between Lake Road West and Lake Road East and is bordered by residential properties that surround this intersection. FEMA Designation The Buck Island Road & Lake Road West sites are located within Other Areas of Flood Hazard, Zone X (0.2% annual chance of flooding with average depth less than one foot or with drainage areas less than one square mile) (Community Panel No. 25001C0586J, effective July 16, 2014)(Figures 3b and 3b-1). Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 18 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Resource Areas The only resource area present at this site includes BVW, located adjacent to each of the two sites (Figure 4d). The BVWs adjacent to each of the locations are associated with Plashes Brook, which flows north to south between Plashes Pond and Parkers River, and crosses through a culvert below Buck Island Road approximately 1,000 feet to the west of the Buck Island Road/Lake Road West intersection. The BVWs adjacent to the site locations are characterized as fingers of low-lying forested swamp wetlands that extend east toward the site locations from the Plashes Brook floodplain corridor. The BVW adjacent to the Lake Road West (PR-4) location is present to the west, along the western sides of the 35, 39, and 41 Lake Road West properties, with its eastern perimeter extending closest to the site within the 39 Lake Road West property (Photo 12). The vegetated wetland is characterized as a forested swamp and is bound by steep slopes rising to the north and east toward residential properties, and by more gently rising slope to the south, toward Buck Island Road. The BVW appears to hydrologically- connected to the Plashes Brook wetland corridor to the west via groundwater interchange at low elevation areas to the west, near Buck Island Road. Common plant species observed within the BVW at this location include red maple (Acer rubrum), pitch pine, black tupelo (Nyssa sylvatica), sweet pepperbush (Clethra alnifolia), and inkberry (Ilex glabra). HW delineated the boundary of the BVW area with a series of consecutive pink flagging stations labeled BVW 100 through BVW 104. Photo 12. Eastern boundary of the BVW/Vegetated Wetland finger (looking northeast from within the wetland) adjacent to the Lake Rd W site location (December 2023) The BVW at the Buck Island Road location (PR-3) is present within the Old Mill Creek Conservation Area, south of the Buck Island Road Right-of-Way (ROW). This BVW is bound by a steep slope that rises up to the Buck Island ROW along its northern perimeter and by more gradually-rising slopes to the east, south, and west. Residential properties are present to the east and south, and there is a section of pitch pine- oak woodland present to the west of the BVW (Photo 13). A small, unnamed perennial stream runs Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 19 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx flows east to west along the southwestern portion of the BVW, maintaining a hydrologic connection to a larger BVW corridor that is present along the east side of Plashes Brook. A desktop review of the Mass Mapper GIS data shows that the section of the stream closest to the proposed project area at 19 Lake Road West is over 200 feet away, and therefore, the project location is outside of the Riverfront Area associated with the stream. Common plant species observed within the BVW at this location include red maple, pitch pine, gray birch (Betula populifolia), sweet-pepperbush, winterberry (Ilex verticillata), inkberry, and sheep laurel (Kalmia angustifolia). HW delineated the boundary of the BVW area with a series of consecutive pink flagging stations labeled BVW 200 through BVW 206. Photo 13. View of the interior of the BVW/Vegetated Wetland (looking southwest) near the northeast corner of the wetland (December 2023) The upland areas adjacent to both of these site locations are primarily comprised of pitch pine-oak woodlands, except for sections where the transition to upland occurred along Buck Island Road and/or onto residential properties. Common species observed within the pitch pine-oak woodlands at both sites include pitch pine, black oak (Quercus velutina), white oak (Quercus alba), American holly, black locust (Robinia pseudoacacia), sweet-pepperbush, inkberry, blackberry, and round-leaf greenbrier. Invasive Species Invasive plant species were observed to be present in relatively low densities within the BVWs/Vegetated Wetlands and/or adjacent uplands at the Buck Island Road/Lake Road West site. Species observed include privet (Ligustrum sp.), Asian bittersweet, multiflora rose, and black locust. Curve Hill Road (UBR-4) The Curve Hill Road site is located at Town-owned land between Curve Hill Road and Four Seasons Drive, on the western side of Yarmouth, approximately half a mile west of Bass River. The site is surrounded by residential properties, except for sections to the north and southwest where it directly borders the Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 20 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Curve Hill Road ROW. The Blue Rock Golf Course is located to the west of the site, just beyond the residential lots on the west side of Curve Hill Road. FEMA Designation The Curve Hill Road site (UBR-4) is located within Other Areas of Flood Hazard, Zone X (0.2% annual chance of flooding with average depth less than one foot or with drainage areas less than one square mile) (Community Panel No. 25001C0586J, effective July 16, 2014) (Figures 3c and 3c-1). Resource Areas BVW is the only resource area present at this site. The BVW area at this site is a wooded swamp wetland (Figure 4e). The BVW’s northern perimeter begins at the southern end of the project site’s property, adjacent to 26 Curve Hill Road and 15 Four Seasons Drive (Photo 14). A continuous BVW corridor extends south from this location to Highbank Road where it connects to an unnamed perennial stream that flows south between Highbank Road and Bass River. The northern finger of the BVW, closest to the project site, is confined by a gradually rising slope to the north and steeper-rising slopes to the east and west. The wetland transitions to a more extensive pitch pine-oak upland woodland to the north, where the proposed project site is located, as well as briefly to the east and west before the woodland perimeters meet with residential property landscapes or the Curve Hill Road ROW. Common species observed within the BVW area include black tupelo, red maple, pitch pine, sweet-pepperbush, Japanese holly (Ilex crenata), highbush blueberry (Vaccinium corymbosum), and sheep laurel. Common species observed in the upland woodlands adjacent to the wetland area include black oak, white oak, pitch pine, American holly, Japanese holly, highbush blueberry, sweet-pepperbush, and round-leaf greenbrier. HW delineated the boundary of the BVW area with consecutive pink flagging stations labeled BVW 100 through BVW 106. Wetland Resources – Stormwater Retrofit Sites in Yarmouth, MA May 21, 2024 Page 21 of 21 H:\Projects\2022\22108 APCC Yarmouth\Reports\Wetland_Memo\240521_Wetland Report_Yarmouth SW Sites_22108A.docx Photo 14. Northern end of the BVW/Vegetated Wetland looking south from adjacent upland (December 2023) Invasive Species Invasive plant species were not observed to be significantly present at the Curve Hill Road site.