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HomeMy WebLinkAboutNarrative 6.8.2023 28 Lots Hollow Road | Orleans, MA 02653 Tel:(508)255-1113 | Fax:(508)255-9477 PERFORMANCE STANDARD NARRATIVE 4 Malfa Road, Yarmouth 6/6/2023 PROJECT INTRODUCTION This project proposes a coastal adaptation strategy that includes a fiber roll array combined with a reinforced high marsh to lessen the severity of erosion, preserve the existing plant community, and provide additional native plant species where none exists. The reinforced high marsh is a below-grade matrix of cobble, compatible sediment, coir fibers, and compost encased in a woven biodegradable material intended to serve as a reinforced rooting medium for transitional high marsh species such as salt marsh hay, spike grass, seaside goldenrod, switchgrass, and American beach grass. In addition, a modest fully biodegradable fiber roll array will be installed along the landward edge of the reinforced high marsh to support the recovery of a coastal dune which has been eroding at a short-term rate of 4’ of loss per year since 2018. The proposed coastal adaptation strategy takes into account anticipated sea level rise. The jurisdictional resource areas under the Massachusetts Wetlands Protection Act: 310 CMR 10.00 and the Town of Yarmouth Wetland Protection Regulations identified within the project area include: Coastal Beach, Coastal Dune, and Land Subject to Coastal Storm Flowage. TOWN OF YARMOUTH REGULATION Proposed work will occur on a Coastal Beach, Coastal Dune, and within Land Subject to Coastal Storm Flowage. Compliance with the performance standards set forth by the Yarmouth Wetland Protection Regulations are described below under the Resource Area headings. The following local regulations were reviewed for this project: • 2.02 Coastal Beaches; • 2.03 Coastal Dunes, and; • 2.10 Land Subject to Coastal Storm Flowage. 2.02 Coastal Beaches (3) Performance Standards: Any activity which is allowed on a coastal beach or tidal flat or within 100 feet of a coastal beach or tidal flat shall not have an adverse effect on the coastal beach or tidal flat by. a) affecting the ability of the waves to remove sand from the beach or tidal flat, • The proposed low fiber roll array and reinforced high marsh are living shoreline strategies meant to restore transitional high salt marsh plant species to the Coastal Beach where none presently exist. Considerable peat bed remnants are located immediately east of the proposed high marsh, within 100 feet of the proposed restoration. The outer layers of coir material around the reinforced marsh provides temporary stabilization to the planting medium during the establishment phase of the planting. The root systems of the established native plants will take the place of the coir blankets as they naturally biodegrade. As sea levels continue to rise, these natural materials should transition to salt marsh peat as tidal conditions are predicted to submerge this area. The proposed reinforced high marsh is specifically designed not to change the ability of the waves to remove sand from the beach any more than the adjacent peat bed, which is the reference ecosystem being restored. b) disturbing the vegetative cover, if any, so as to destabilize the beach or tidal flat, • There is no existing vegetation on the Coastal Beach within the proposed project area that would be disturbed. The proposed reinforced high marsh will establish an appropriate native cover of vegetation where none currently exists. 2 c) causing any modification of the beach or downdrift beach that would increase the potential for storm or flood damage, • The proposed reinforced high marsh will be installed at an elevation that is consistent with the existing elevation of the Coastal Beach and will not cause any wave deflection or potential for storm damage. The establishment of the native vegetation on the Coastal Beach within the reinforced high marsh will help to absorb wave energy and lessen the chance of storm or flood damage. • The proposed low fiber roll array is comprised of materials as soft of softer than beach sand, so no wave deflection could be created from these natural materials. d)interfering with the natural movement of the beach or tidal flat, • The proposed reinforced high marsh is a living shoreline technique meant to restore transitional high salt marsh plant species to the Coastal Beach where none currently exist. The outer layers of coir material around the reinforced marsh provides temporary stabilization to the planting medium during the establishment phase of the planting. The root systems of the established native plants will replace the biodegradable coir blankets as they break down. • The proposed low fiber roll array is intended to serve only as a rooting medium to aid in the establishment of native plant roots. The recent short-term erosion rate of 4’ per year has eliminated the opportunity for the establishment of plant roots. • There is no activity proposed in a Tidal Flat. e) causing artificial removal of sand from the beach or downdrift beach. • The proposed low fiber roll array and reinforced high marsh will cause no artificial removal of sand from the beach. Established native vegetation is known to naturally accrete sand, but not in volumes that would change the littoral movement of sand to a downdrift beach. 2.03 Coastal Dunes (3) Performance Standards: Any activity which is allowed on a coastal dune or within 100 feet of a coastal dune shall not have an adverse effect on the coastal dune by: (a) affecting the ability of waves to remove sand from the dune; • The proposed fiber roll array has been located outside of the Coastal Dune and the top elevation has been reduced from the original design. The lower elevation of the fiber rolls will allow waves to overtop the installation and remove sand from the Coastal Dune. Additionally, these completely biodegradable fiber rolls are temporary in nature and solely intended to stabilize soils long enough to establish the root systems of native dune vegetation. The proposed annual nourishment will maintain the dune as a sediment source to ensure the removal of sand from the Coastal Dune in the future. • This Coastal Dune has a short-term erosion rate of 4’ per year since 2018. With an average depth of only 36’ (measured seaward to landward) remaining, at the current short-term rate of erosion, the entire Coastal Dune is expected to be lost in less than a decade. When the Coastal Dune resource is lost, the regulatory protections are lost with it. A long-established lawn area exists immediately on the landward side of the Coastal Dune. When erosion removes the Coastal Dune and enters into the coastal lawn, there would be an immediate threat to this pre- 1978 home and consequently no prohibition of installing a Coastal Engineering Structure (CES). The primary goal of this project is to preserve and enhance the Coastal Dune and avoid the necessity of a CES within less than a decade. (b) disturbing the vegetative cover so as to destabilize the dune; • No actions are proposed that would disturb the existing native vegetation on the Coastal Dune. The proposed nourishment and planting of American beachgrass will increase the vegetative cover of the dune. The subject Coastal Dune has a short-term erosion rate of 4’ per year. With an average depth of only 36’ (measured seaward to landward) remaining, the entire Coastal Dune is expected to be lost in less than a decade. When the Coastal Dune resource is lost, the regulatory protections are lost with it. A long-established lawn area exists immediately on the landward side of the Coastal Dune. When the erosion removes the Coastal Dune and enters into the coastal lawn, there would be a direct threat to this pre-1978 home and therefore not prohibition of installing a Coastal Engineering Structure (CES). The primary goal of this project is to preserve and enhance the Coastal Dune and avoid the necessity of a CES within less than a decade. 3 (c) causing any modification of the dune form that would increase the potential for storm or flood damage; • The proposed nourishment and planting of American beachgrass over the dune will not increase the protentional for storm or flood damage. These actions will enhance protection of the Coastal Dune from storm and flood damage. (d) interfering with the landward or lateral movement of the dune; • The proposed fiber roll array has been revised to a lower elevation than the previously submitted plan. The reduced elevation will allow waves to over top the installation, and transport sediment from the Coastal Dune. The proposed annual nourishment of the Coastal Dune will support and enhance its function as a sediment source. (e) causing artificial removal of sand from the dune; or • The project is proposing to nourish the Coastal Dune with compatible sediment. These actions will not cause artificial removal of sand from the dune. (f) interfering with mapped or otherwise identified bird nesting habitat. • The property is not mapped for rare bird species by The Natural Heritage and Species Program (NHESP) and there are no identified birds nesting habitat. Though the proposed nourishment and planting of American beachgrass over the Coastal Dune will not inter with nesting habitat once completed. (4) The following projects may be permitted, provided they adhere to the provisions of section 2.03, (3): (a) elevated pedestrian walkways, designed to minimize disturbance to vegetative cover, and traditional bird nesting habitat. Walkways shall have a minimum clearance of two feet above any existing vegetation; • No walkways are proposed. An existing foot path through the dune is to remain. (b) fencing and other devices designed to increase dune development; and • The existing wooden snow fencing will be reinstalled following the proposed nourishment and planting of American beachgrass. (c) plantings compatible with the natural vegetative cover. • The proposed planting of American beachgrass over the Coastal Dune is compatible with the existing vegetative cover. 2.10 Land Subject to Coastal Storm Flowage (3) Performance Standards: Any activity within land subject to coastal storm flowage which will result in the building upon, removing, filling or altering land within 300 feet of a major estuary defined in section 1.04 of these regulations shall meet the following requirements. Notwithstanding this section 2.10, (3), beach nourishment and coastal engineering projects such as bulkheads and seawalls may be allowed if they meet all other performance in these regulations. • The proposed project meets the performance standards for Coastal Beaches and Coastal Dunes as listed on pages one through three of this Performance Standard Narrative. (a) Existing septic system and cesspool repairs will be allowed provided they substantially meet all Title 5 and local Board of Health thresholds. (b) All groundwater elevations shall incorporate seasonable adjustments if test holes and or leaching components are 100 feet or closer from major estuaries. (c) Any proposed deck, shed, or other similar structure must be securely anchored to a footing or foundation. • The project does not include septic system repairs or structures. Not applicable. MASSACHUSETTS WETLANDS PROTECTION ACT Proposed work will occur on a Coastal Beach, Coastal Dune, and within Land Subject to Coastal Storm Flowage. Compliance with the performance standards set forth by the Massachusetts Wetland Protection Act are described below under the Resource Area headings. The following regulations were reviewed for this project: • 10.04 Land Subject to Coastal Storm Flowage (no Performance Standards); • 10.27 Coastal Beaches, and; • 10.28 Coastal Dunes. 4 10.27 Coastal Beaches When a coastal beach is determined to be significant to storm damage prevention, flood control, or protection of wildlife habitat, 310 CMR 10.27 (3) through (7) shall apply: (3) Any project on a coastal beach, except any project permitted under 310 CMR 10.30(3)(a), shall not have an adverse effect by increasing erosion, decreasing the volume or changing the form of any such coastal beach or an adjacent or downdrift coastal beach. • The proposed reinforced high marsh will be installed at an elevation that is consistent with the existing elevation of the Coastal Beach and will not cause any wave deflection or potential for storm damage. The establishment of the native vegetation on the Coastal Beach will absorb wave energy and lessen the chance of storm or flood damage. As sea levels continue to rise, these natural materials should develop into salt marsh peat as tidal waters are predicted to submerge this area. The proposed reinforced high marsh is specifically designed not to change the ability of the waves to remove sand from the beach any more than the adjacent peat bed, which is the reference ecosystem being restored. (4) Any groin, jetty, solid pier, or other such solid fill structure which will interfere with littoral drift, in addition to complying with 310 CMR 10.27(3), shall be constructed as follows: • The proposed project does not include a groin, jetty, solid pier or other solid fill structure. (5) Notwithstanding 310 CMR 10.27(3), beach nourishment with clean sediment of a grain size compatible with that on the existing beach may be permitted. • The Coastal Beach contains surficial gravel and smaller cobble within the typical medium to fine grain sand that comprise this Coastal Beach. These small surficial cobbles were found to be concentrated in the vicinity of the spring high tide line. Refer to Image 1 below. IMAGE 1 – Photo showing smaller surficial cobbles on Coastal beach. • Three test holes were dug at a depth of 18” deep within the Coastal Beach to evaluate the quantity and size of existing sub-surface cobble. The test holes were located within the proposed footprint of the reinforced high marsh, at the western terminus, center, and eastern terminus of the installation. The cobbles that were identified in the test hole measured between 3” to 5” in size. The cobble from each test hole were photographed and the images included below. The cobbles in the proposed reinforced high marsh have been redesigned to be smaller in order to be compatible with the existing sediments. 5 IMAGE 2 – Photo showing cobbles that were found in the western test hole. IMAGE 3 – Photo showing cobbles that were found in the central test hole. 6 IMAGE 4 – Photo showing cobbles that were found in the eastern test hole. 10.28 Coastal Dunes: When a coastal dune is determined to be significant to storm damage prevention, flood control, or protection of wildlife habitat, 310 10.28 (3) through (6) shall apply: (3) Any alteration of, or structure on, a coastal dune or within 100 feet of a coastal dune shall not have an adverse effect on the coastal dune by: (a) affecting the ability of waves to remove sand from the dune; • The proposed fiber roll array is proposed outside of the Coastal Dune and the top elevation has been reduced. The lower elevation of the fiber rolls will allow waves to over top the installation and remove sand from the Coastal Dune. The fully biodegradable low fiber roll array is proposed solely as a stable rooting medium to allow vegetation to develop in the Coastal Beach. The proposed annual nourishment will maintain the dune as a sediment source to ensure the removal of sand from the Coastal Dune in the future. • The subject Coastal Dune has a short-term erosion rate of 4’ per year. With an average depth of only 36’ (measured seaward to landward) remaining, the entire Coastal Dune is expected to be lost in less than a decade. When the Coastal Dune resource is lost, the regulatory protections are lost with it. A long-established lawn area exists immediately on the landward side of the Coastal Dune. When the erosion removes the Coastal Dune and enters into the coastal lawn, there would be a direct threat to this pre-1978 home and therefore not prohibition of installing a Coastal Engineering Structure (CES). The primary goal of this project is to preserve and enhance the Coastal Dune and avoid the necessity of a CES within less than a decade. (b) disturbing the vegetative cover so as to destabilize the dune; • No actions are proposed that would disturb the existing native vegetation on the dune. The proposed initial nourishment and planting of American beachgrass will increase the vegetative cover of the dune. The subsequent annual nourishment of approximately five inches of sand per year will not negatively affect American beachgrass as “this plant species is capable of surviving when buried to a depth of 0.3 meter (11.8 inches) by wash over deposits”. • Knutson, P. L. (1980). Experimental dune restoration and stabilization, Nauset beach, Cape Cod, Massachusetts. https://erdc-library.erdc.dren.mil/jspui/handle/11681/22208 7 (c) causing any modification of the dune form that would increase the potential for storm or flood damage; • The proposed nourishment and planting of American beachgrass over the dune will not increase the protentional for storm or flood damage. These actions will enhance protection of the Dune from storm and flood damage. (d) interfering with the landward or lateral movement of the dune; • The proposed fiber roll array is located seaward of the Coastal Dune and has been revised to a lower elevation than the previously submitted plan. The reduced elevation will allow waves to over top the installation, and transport sediment from the Coastal Dune. The proposed annual nourishment of the Coastal Dune will maintain its function as a sediment source. (e) causing removal of sand from the dune artificially; or • The project is proposing to nourish the dune with compatible sediment. These actions will not cause artificial removal of sand from the dune. (f) interfering with mapped or otherwise identified bird nesting habitat. • The property is not mapped for rare bird species by The Natural Heritage and Species Program (NHESP) and there are no identified birds nesting habitat. Though the proposed nourishment and planting of American beachgrass over the Coastal Dune will not inter with nesting habitat once completed. (4) Notwithstanding the provisions of 310 CMR 10.28(3), when a building already exists upon a coastal dune, a project accessory to the existing building may be permitted, provided that such work, using the best commercially available measures, minimizes the adverse effect on the coastal dune caused by the impacts listed in 310 CMR 10.28 (3)(b) through 10.28(3)(e). Such an accessory project may include, but is not limited to, a small shed or a small parking area for residences. It shall not include coastal engineering structures. • No structure, accessory or coastal engineering structure is proposed with this project. (5): The following projects may be permitted, provided that they adhere to the provisions of 310 CMR 10.28(3): (a) pedestrian walkways, designed to minimize the disturbance to the vegetative cover and traditional bird nesting habitat; • No walkways are proposed. An existing foot path through the dune is to remain. (b) fencing and other devices designed to increase dune development; and • The existing wooden snow fencing will be reinstalled following the proposed nourishment and planting of American beachgrass. (c) plantings compatible with the natural vegetative cover. • The proposed planting of American beachgrass over the dune is compatible with the existing vegetative cover. (6) Notwithstanding the provisions of 310 CMR 10.28(3) through (5), no project may be permitted which will have any adverse effect on specified habitat sites of rare vertebrate or invertebrate species, as identified by procedures established under 310 CMR 10.37. • The Massachusetts Natural Heritage Atlas of Estimated Habitats of Rare Wetland Wildlife, Certified Vernal Pools and High Priority Sites of Rare Species dated, August 12021, indicates that there are no protected species or rare communities on the property.