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HomeMy WebLinkAboutGIHA Rqst for Emergency Certification to CC_12-28-2023 December 29, 2023 Job No. 23-0169-00 Ms. Brittany DiRienzo Yarmouth Conservation Administrator 1146 Route 28 South Yarmouth, MA 02664 Sent via email: bdirienzo@yarmouth.ma.us Request for Emergency Certification – Great Island Homeowners Association Dear Ms. DiRienzo: On behalf of our clients, the Great Island Homeowners Association (GIHA), Woods Hole Group is requesting that the Yarmouth Conservation Commission issue an Emergency Certification per 310 CMR 10.06 for rebuilding portions of the primary coastal dune that were damaged during the December 18, 2023 storm. Information is provided below on (i) need for the work to protect public health and safety, (ii) December 18, 2023 storm characteristics and extent of damage to the dunes, (iii) and details of the proposed restoration work. Need for the Work to Protect Public Health and Safety While Great Island is largely a seasonal home for many of its inhabitants, there are families that live on the island year-round. Some of the year-round residents are in their 70s and 80s and in poor health. The ability to provide medical and fire services to these residents in case of an emergency is of utmost importance to the GIHA. Loss of the primary coastal dune along the Nantucket Sound side of Great Island Road significantly increases the vulnerability of the roadway, which serves as the only means of vehicle and emergency access to the island. Without protection of the coastal dune, the roadway, and associated utilities that serve the island are vulnerable to damage during future storms. With a large enough storm, damage along Great Island Road could render the roadway impassable, creating a threat to public health and safety for the island’s year-round residents. Woods Hole Group visited the site with Yarmouth Fire Captain, Kevin Huck, on December 26, 2023 to assess public health and safety issues associated with the existing roadway. Captain Huck expressed concerns about the ability of emergency responders to reach the island if further damage to the roadway occurs. A site visit was also conducted by a transportation engineer from Fuss & O’Neill on December 22, 2023. Conclusions from the site visit indicated no immediate threats to the bridge or roadway infrastructure; however, restoration of the dunes in areas where the road is flush with the beach were recommended to minimize the potential for roadway damage during future storms. As demonstrated, the request for an Emergency Certification to restore the primary coastal dune is needed to protect public health and safety. December 18, 2023 Storm Characteristics and Extent of Damage to the Dunes On December 18, 2023, a strong area of low pressure moved across the Great Lakes. A new area of cyclogenesis occurred off the southern New Jersey coastline. Very strong southeast winds developed across New England and built significant waves in Nantucket Sound. The significant wave heights in Nantucket Sound at NOAA buoy 44020, located 7.8 miles due south of Great Island, reached 7.5 feet with waves approaching the shoreline from the southeast. Water level data from nearby gauges in Woods Hole and Hyannis Harbor showed a storm surge of nearly Page 2 of 5 2.0 feet (5.8 feet NAVD88). A similar meteorological event, synoptically, occurred on December 23, 2022. On that day, NOAA buoy 44020 recorded a significant wave height of 6.4 feet as waves traveled from the southeast. While the annual exceedance probability for these two events is quite low, our climate continues to change and the exceedance probabilities for these types of coastal storms are expected to increase. The December 18, 2023 storm caused extensive damage to two (2) portions of the primary frontal dune protecting the south side of Great Island Road. The areas that sustained the greatest damage are indicated by the red circles in Figure 1. Damage at the northern site extends along approximately 600 linear feet of the shoreline while damage at the southern site extends along approximately 950 linear feet of shoreline. Erosion along the 600-foot- long section north of the ‘S’ curve damaged a portion of the dune restoration project that was previously installed in this area following the 2022 storm. Photos showing damage to the dunes in the northern and southern areas are provided in Figures 2 and 3, respectively. Figure 1. Areas of coastal dune along Great Island Road damaged during the December 18, 2023 storm. Page 3 of 5 Figure 2. Photos of damage to the coastal dune at the northern site. Page 4 of 5 Figure 3. Photos of damage to the coastal dune at the southern site. Details of the Proposed Restoration Work The request for Emergency Certification covers restoration of the primary dune that existed prior to the December 18, 2023 storm. Survey information on the Foth Existing Conditions plans revised 7/14/2022 and filed with the Notice of Intent SE 083-2359 for beach and dune nourishment were used to identify the condition of the dunes present on site prior to the storm. These plans show that the northern dune crest ranged in elevation from 10 to 11 feet NAVD88, with a dune width between 20 and 40 feet. Dune crest elevations at the southern site were 7 ft NAVD88, with a dune width between 16 and 35 feet. The planned work includes restoration of the primary dune to these same crest elevations and widths that existed prior to the December 18, 2023 storm. It is estimated that up to 3,000 cubic yards of material will be needed to restore the dunes to their pre-storm condition. All dune restoration work will take place above the annual high tide line. The proposed work will be conducted in compliance with the May 2007 MassDEP Guidance to Homeowners and Conservation Commissions Relate to Storm Emergency Certification for Rebuilding of Primary Coastal Dunes. Specifically, dune compatible sand will be replaced in areas where the storm caused erosion, in order to provide temporary stabilization of the site. The work will conform to the following provisions: a) Sand will not be removed from the existing Coastal Dune or Coastal Beach resources. Rather, the project involves the addition of sand to the site to restore the Coastal Dune resource. Page 5 of 5 b) Sand used for the project will be compatible in grain size to the existing dunes. Woods Hole Group collected sediment samples from areas of the remaining dune and sent them for grain size analysis at an approved laboratory. These data will be used to source compatible sand from local sources. Once a compatible source has been identified, and prior to construction, the Conservation Commission will be provided with the grain size data for approval. Work will not proceed until the Conservation Commission approves the sediment source. c) Prior to construction, information on the selected contractor, sediment source, and sediment volume (expected to be up to 3,000 cubic yards) will be provided to the Conservation Commission for approval. All materials will be trucked to the site and dumped along the south side of the roadway in the northern and southern work areas. A rubber-tired front-end loader will be used to grade the sand to the pre- existing dune profiles. Staking will be established in the field by Woods Hole Group to delineate dune crest elevations and footprints. d) It is expected that most work by the front-end loader will be performed from the road side of the work area, with limited work from the Coastal Beach. e) No sand placement will take place on vegetated portions of the remaining dune. Woods Hole Group will work with the GIHA and selected contractor to ensure that all work is completed within 30 days of issuance of the Emergency Certification and that a post construction Notice of Intent (NOI) is filed for the work. It should be noted that the proposed work is a temporary solution to fix an emergency situation created by the December 18, 2023 storm. Being aware of the growing concerns of rising sea level and climate change, the GIHA recently hired Woods Hole Group to conduct a feasibility study for long-term resiliency of Great Island and White Cedar Point Roads. The goal of the project is to find environmentally friendly and permittable solutions to reduce the overall vulnerability of the roadway through the year 2070. If you have any questions or require additional information, please give me a call at 508-495-6217 or send an email to cgloninger@woodsholegroup.com. Thank you for your assistance and consideration. Sincerely, Chris Gloninger, M.S., B.S. Senior Scientist in Climate and Risk Communication CG/beg cc: Great Island Homeowners Association Peter D. Van Oot, Esq.