Loading...
HomeMy WebLinkAbout2023-03-09_203 Scudders_Monitoring Report_redMONITORING REPORT 2022 To: Conservation Commission Attn: Darcy Karle, Agent 200 Main Street Hyannis, MA Project: Bank Stabilization Location: 203 Scudder’s Lane, Barnstable MassDEP File: SE 3-5789 Project No: C19242.00 Report Date: 03-10-2023 Present on Site: Catherine Ricks – CEC Weather: Sunny, 48°F Wind: N 9 mph Date of Site Visit: 02-14-2023 Time: 11:00 – 12:00 Observations: Coastal Bank – The toe of the Coastal Bank is armored with a rock revetment along most of the property. On the eastern side of the property, the revetment has an elevation taper which transitions to a fiber roll array that spans across the lot line to the abutting property at 211 Scudder’s Lane. More of the sacrificial nourishment that once covered the fiber rolls has been eroded. The coir netting covering the fiber rolls is damaged in the transition area. Just to the east of the rock revetment, the coir netting is damaged and attached, tapering down to the beach. The coir netting beyond this point is completely missing. The fiber rolls are well anchored and show no signs of damage. The areas along the face of the Coastal Bank above the fiber rolls and revetment are stabilized with turf reinforcement matting (TRM). The TRM is well-anchored along the bank. The vegetation planted underneath the TRM is growing well through the voids of the TRM fabric. Most of the beach grass that was planted on the sacrificial nourishment has been eroded away. However, there is surviving beach grass in the areas where sacrificial nourishment still exists. The area previously identified on the face of the coastal bank near the eastern lot line where there are signs of upland erosion caused by rain runoff have not seen a significant change. The vegetation in this area is still not growing as well as the rest of the bank but has not degraded further. Another area along the face of the bank that showed signs of upland erosion was directly to the east of the stairs. This area sustained damage from upland erosion prior to the completion of construction and the installation of the catch basin in the upland area. When comparing photos between the present and the previous monitoring report, the damaged area looks like it is improving. The vegetation in this area is continuing to slowly grow back. The ruts formed on the bank are no larger than they were at the time of the last site visit. Overall, the Coastal Bank looks well stabilized and vegetated except in the area near the eastern lot line where there are signs of runoff erosion from the upland. Coastal Beach – The upper portions of the Coastal Beach along the toe of the Coastal Bank has a heavy amount of wrack. The damaged portion of the coir netting that was once staked and covering the fiber rolls is slumped and tapered at the end of the revetment and otherwise completely gone from covering the fiber rolls. Upland area – The vegetation planted along the top of the bank and the sod planted in the backyard is growing well. There are no signs of stormwater runoff overtopping the Coastal Bank near the staircase. The upland area along the eastern lot line above the eroded area of the bank was inspected. The grading in this heavily vegetated area funnels toward the area of erosion. Summary: The site was inspected by an engineer from Coastal Engineering Company, Inc. to document the existing conditions of the site since the previous monitoring inspection was completed. Items documented include the plant survivability, evidence of erosion, condition of the shorefront protection system, stability of the Coastal Bank, and recommendations. Plant Survivability – There has been no major changes in plant survivability since the previous report. The beach grass that was planted along the lower portions of the bank on top of the sacrificial nourishment was not replanted. The sacrificial nourishment and associated beach grass remains eroded. The plants that were installed above the fiber rolls and revetment are surviving well. The plants along the face and top of the Coastal Bank look healthy and densely populated. There is one area along the Coastal Bank near the eastern lot line where the plants are sparce due to upland erosion undermining the TRM, however, there has been no degradation from the previous year. Evidence of Erosion – There has been no major changes in evidence of erosion since the previous report. The lower portions of the Coastal Bank in the transition zone between the revetment and fiber rolls show signs of erosion. Most of the sacrificial nourishment remains eroded away. The upper portions of the beach have a large amount of wrack. One area of the bank near the eastern lot line shows signs of upland erosion caused by rain runoff, but no significant change from the previous year. Condition of the Shorefront Protection System – There has been no major changes to the condition of the shorefront protection system. The shorefront protection system that was installed consists of a rock revetment along most of the shoreline with a transition to an anchored fiber roll array on the eastern lot line. The fiber roll array was installed along the toe of the Coastal Bank and was covered with sacrificial nourishment and planted beach grass. Above the fiber roll array and rock revetment, on the face of the Coastal Bank is an anchored turf reinforcement matting (TRM) with a mix of coastal grasses planted underneath the fabric. Overall, the system is in good shape. The revetment shows no signs of slumping or settlement. Most of the sacrificial nourishment and beach grass plantings remain eroded away, but the fiber roll array remains properly anchored and does not show any signs of damage. The coastal grasses and shrubs along the face and upper Coastal Bank show signs of growth and appear to be healthy. The TRM remains anchored to the face of the bank. One area of the bank near the eastern lot line shows signs of erosion due to upland rain runoff, however, the area has not degraded since the previous report and the grasses in this area are growing slowly and the rut has not grown underneath the TRM. Stability of the Coastal Bank – There has been no major changes to the stability of the Coastal Bank. Overall, the coastal bank is stable. Most of the toe of the bank is armored with the rock revetment. The toe of the bank protected by the fiber roll array has not been compromised as the fiber rolls are still intact and protect the bank from storm erosion. The face of the bank is well vegetated, as the beach grass and other grasses are growing well through the fabric of the TRM. The drainage improvements installed in the upland area are functioning properly. There is one area of the coastal bank near the eastern lot line that shows signs of erosion due to upland rain runoff. Recommendations – Overall the shorefront protection system is in good condition. Some of the same small maintenance activities recommended in the previous report could be completed to potentially promote the longevity of the system. The exposed areas of the fiber rolls could be covered with sacrificial nourishment and planted with beach grass. This would help prevent UV ray degradation from occurring to the fiber rolls in the short-term. It is likely that the sacrificial nourishment will eventually erode again. See attached pictures below. Submitted by: Matthew Turcotte – Staff Engineer, CEC Photo 1: Area of Coastal Bank Near Eastern Lot Line. Evidence of Upland Runoff Erosion. (Left: 2022, Right: 2021) Photo 2: Coastal Bank and Rock Revetment. Vegetation Growing Well, Revetment Stable. (Left: 2022, Right: 2021) Photo 3: Vegetation on Face and Upper Coastal Bank Growing Well. (Left: 2022, Right: 2021) Photo 4: Drainage Improvements Functioning Properly. (Left: 2022, Right: 2021)