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HomeMy WebLinkAboutNOI 4.29.24 Narrative Notice of Intent 911 Great Island Road, West Yarmouth, MA Sediment Replenishment The area subject to this Notice of Intent is a west facing Coastal Beach resource area associated with Nantucket Sound. Please see the locus map for the exact location. The general reach of shoreline is a segment of Great Island coastline, a rocky, glacial moraine remnant landform dividing Nantucket Sound from Lewis Bay. The specific reach of coastline has been eroding in some measure for decades, due to natural forces of the wind, tides and large vessel wakes from the Nantucket Island ferry traffic navigating the Hyannis Harbor channel. Sediment supply interruptions and related effects are due in part to the older stone groins and stone breakwater formations (WW License No. 197) that populate the circumference of Great Island. The beach deposit consists of medium textured quartz sand with an abundance of slipper shells, pebbles, and cobble stones. Past erosion management projects at this site incorporated anchored fiber rolls with sand fill as an effort to inhibit coastal bank erosion. Those measures have failed with scattered debris and corroded cables populating the beach area. The applicant intends to add sediment replenishment to the beach landward of the high-water line at the beach bank juncture. The sediment will result in a minor elevation increase to reduce storm damage to the Coastal Bank. The sand supply will be meted out as storm tides encounter the sand in the proposed location along the coastal bank. A secondary purpose of this NOI is to access the same beach area to retrieve and dispose of the disassembled, scattered coir rolls and anchor tethers. The 2009 Order of Conditions (SE83-1852) included sediment replenishment. The purpose was to maintain sand cover on the coir roll array. The applicant intends to seek an Order of Conditions to add sediment as a means of maintaining a beach elevation for purposes of reducing erosion of the Coastal Bank. The activity supports the common wetland interests of storm damage prevention and flood control, replenishing a Coastal beach deposit in a state of sediment deficit. Sieve analysis of the existing sediment shows the soil texture highly consistent with commonly available upland sources. Some of the established on-site soil is upland sourced. The current proposal calls for an upland source. Sand volume of approximately 600 cubic yards can be delivered via the previously used access route along the north lot boundary from Great Island Rd. The activity for adding sand fill will be a continuous activity as the material is placed and a rubber tired front-end loader will distribute material in the area shown on the plan. The process of delivery is described at 10 trips per day of 20 c.y. each for a term of 3 days. A portion of the site encompassing approximately 50% of the project area on the north end is within a NHESP mapped Priority Habitat. It is anticipated that a time of year restriction for sand work activity will be part of the protocol for the sediment replenishment. The activity will have no adverse effect in the intertidal area. The material will be dispersed over time and will benefit the beach deposit in this area which has been affected for more than half a century by the older offshore stone formations interrupting the on-shore migration of sediment. IMAGES COASTAL BEACH AT 911 AND 921 GREAT ISLAND ROAD, WEST YARMOUTH APRIL 19 - 22, 2024 Figure 1 – View south of 911 Great Island Rd. beach. # 921 beach in distance near glacial erratic. Figure 2 – View north of 911 Great Island Rd. beach Figure 3 – View south of 921 Great Island Rd. beach. Figure 4 – View south of 911 Great Island Rd. beach Project Name:Tested By:R. Perry Date:4/21/2024 Location:Sampled by:R. Perry Date:4/19/2024 Boring No:Test Number:1 Sample Depth:Gnd Elev.:4 NAVD 88 USCS Soil Classification: Comment: Weight of Container (g):N/A Weight of Container & Soil (g):N/A Weight of Dry Sample (g):346.7 Sieve Number Diameter (mm) Mass of Sieve (g) Mass of Sieve & Soil (g) Soil Retained (g) Soil Retained (%) Soil Passing (%) #4 4.75 0.0 0.0 100.0 #10 2.00 0.0 0.0 100.0 #20 0.84 3.4 1.0 99.0 #40 0.43 218.7 63.1 35.9 #60 0.25 109.8 31.7 4.3 #100 0.15 12.8 3.7 0.6 #200 0.075 0.3 0.1 0.5 Pan 0.0 0.0 0.0 TOTAL:345.0 99.5 Sieve Diameter (mm)% Passing % Passing 4 4.75 100 10 2 100 40 0.425 100 200 0.075 100 4 4.75 0 10 2 0 40 0.425 0 200 0.075 0 % Gravel:0 D10:0.29 Cu:1.8 % Sand:100 D30:Cc: % Fines:0 D60:0.53 Cu = 2.3 - Poorly graded (Med. sand.) Muncell color 2.5 Y 7/2 (light); Clean; 1.7 g. seive screen loss Grain Size Distribution Curve Results: Sieve Analysis Data Sheet - Cape Cod Engineering, Inc. PO BOX 1517, EAST DENNIS, MA 02641 - 508-385-1445 AWAD - BEACH 911 Great Isle. Rd. N/A 0 - 8 inch composite 0 10 20 30 40 50 60 70 80 90 100 0.010.101.0010.00% PassingParticle Diameter (mm) #4 #10 #40 #200GRAVELCoarse SAND Medium SAND Fine SAND SILT/CLAY 14.333 Sieve Analysis Worksheet Revised 02/13 __ of __