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HomeMy WebLinkAboutAcheson_Monitoring Report_2024-10 MONITORING REPORT DEP File Number: SE 83-2279 Project Address: 162B Pleasant Street Assessment Period: October 2023 – October 2024 Project Documents: Site Plan Showing the Proposed Re-Building of an Existing Licensed Pier System in and Over the Waters of Bass River by Down Cape Engineering, Inc., signed and stamped by Daniel A Ojala, P.E., P.L.S., dated 5/8/2021 Project Overview This project involved the re-building of an existing pier system in and over the waters of Bass River, along with the installation and anchoring of a coir roll array. After installation of the coir roll array was covered with coir matting and nourished with compatible native sand. The array was then planted with a mix of native shrubs and grasses to aid in bank stabilization. Project Activities Completed during Assessment Period In November 2023, the supplemental High-tide bush plantings were installed at the toe of the coastal bank in front of the coir envelope array. A storm check was completed in December 2023, as well as a couple storm checks in January 2024 after winter storms. Maintenance visits were conducted in late May, mid-August and mid-September 2024. Assessment of Current Site Conditions Coir Fiber Roll Array During the December 2023 storm check, the coir array was intact and no damage was incurred, although it was recommended that the array be covered with more supplemental nourishment. It appeared as though the wrack line served as a good buffer between wave action and the coastal bank. Storm checks were also completed in early/mid-January 2024, at which time the coir array exhibited some signs of scarping at the top of the bank above the uppermost coir log. It was at this time that the addition of another row of coir logs was suggested. Invasive Species Management Invasive species were still present along the coastal bank, but in very minimal quantities. Invasive species present included primarily Oriental bittersweet (Celastrus orbiculatus) and porcelainberry (Ampelopsis brevipedunculata). Some aggressive, weedy species were present, including smartweed (Persicaria pensylvanica) and curly dock (Rumex crispus). Control of invasive and aggressive vegetation is not a major concern, and appears to have been effectively controlled with only minor maintenance upkeep necessary. Restoration Planting Establishment Of the plantings on the coastal bank, the plantings on the leading edge have had the most difficulty establishing, likely due to repeated wave energy from storms and more exposure to regular tidal inundation. Beach grass continues to establish and spread in some areas but needs to be replanted each season as it continues to be removed, along with nourishment, following storm season. Seaside goldenrod (Solidago sempervirens) has had much more success establishing, especially in the middle portion of the bank. Approximately 50% of the supplemental High-tide bush that were planted have survived the first growing season. These plantings were not required per the permit, but were planted because it was believed they could provide an added buffer layer to protect the bank. It is recommended that another effort is made to re-plant those that did not survive, and that supplemental irrigation is installed to help them survive and establish until they can be self-sustaining. Anticipated Activities to be Completed Next Monitoring Period Over the next monitoring period, CLM anticipates completing the following activities: • Monitor restoration area and perform maintenance treatments or hand weed invasive, non-native, and aggressive species that have germinated from existing seed bank or re-sprouted from roots remaining in the soil. • Monitor the coir roll array, especially following storm events, to assess any damage and nourish as necessary. • Continue to place supplemental nourishment and re-plant with American beach grass, as necessary. The goal is that storm season(s) are benign enough for 1-2 seasons to allow beach grass to establish and help hold sediment in place. Due to the nature of the site, nourishment will continue to be necessary to keep coir logs covered and prevent their degradation. Recommendations for any Changes in Land Management Techniques It is recommended that if the homeowner is supportive of replacing the supplemental High- tide bush that did not survive their first growing season that supplemental irrigation is installed to help them become established. It is also recommended that if these shrubs are re-planted that they be planted in early spring rather than late fall so that they can establish during the growing season and be more prepared for storm season. Unexpected or Arbitrary Changes to the Project Area Some signs of scarping were observed at the top of the coir array above the uppermost coir log. CLM has had conversations with the homeowner about pursuing the addition of an additional row of coir logs at the top of the array to prevent this scarp from progressing. Representative Project Area Photographs Coastal bank following planting of supplemental High-tide bush. November 2023. Coastal bank during late season maintenance visit. August 2024. Parts of the top of the bank show signs of scarping – the homeowner may want to pursue the addition of another fiber roll above the existing array. May 2024.