Loading...
HomeMy WebLinkAboutNarrative 8.27.2026 1 PROJECT NARRATIVE 85 MERCHANT AVENUE, YARMOUTH PORT, MA STONE REVETMENT RENOVATION August 27, 2026 The area subject to this Notice is land within and on the immediate shoreline of Follins Pond, a salt pond. This area has been significantly altered over the past 70 years by residential construction and shoreline stabilizing. Offshore of locus is the regularly dredged main channel for Bass River. On the pond shoreline there exists a stone revetment protecting the upland. Within the specific project area there is a fringe Salt marsh and further out, a firm sandy, mud bottom as the sub-tidal area extends out. The existing coastal wetland resource areas directly affected include: • Coastal bank • Coastal beach • Salt marsh • Land Containing Shellfish • Land subject to coastal storm flow Nearby coastal resources include: • Land under the ocean (to the northeast seaward of the low tide line) The nearby resource areas will be unaffected by the work with adherence to appropriate work practices. The revetment is licensed by Chapt. 91 License number WW01-0000613. It has existed for approximately 40 years and is deteriorated, with accompanying erosion. REVETMENT REPLACEMENT – The work activity necessary to remove and properly reset the stones with appropriate technique requires a careful process of controlled construction, minimizing machine size, minimizing machine access and staging alteration followed by effective ground restoration. The goals and interests of the relevant wetland regulations are consistent with the applicant’s goals because the project intent is to stabilize the bank at this location for purposes of protecting the dwelling. The dwelling foundation is as close as 7.5 ft. from the crest of the unstable bank slope. The foundation footing is well below the ground surface allowing the building to remain stable during the work effort. The specific project area involving the revetment reconstruction is a Coastal Bank below the 100-year flood elevation along the northeast facing segment of the pond coastline currently armored with a deteriorating stone revetment. Access for revetment work is practical by crossing the upland on site. The work activity shall be limited to the specific land area currently containing the stones and the adjoining upland. No seaward encroachment of work activity is intended or permitted. The work effort shall be organized, staged in the existing lawn area, with all of the stone work occurring from the side 2 and from the top. The work protocol, as an addendum to this narrative outlines the methods and tactics by which Cape Cod Engineering; Inc envisions the work to be carried out. As a renovation of an existing stone revetment with the objective of bank stability improvement, the project serves the interests of storm damage and flood control and is consistent with performance standards for 310 CMR 10.30 of the Wetland Regulations and the Yarmouth Wetland Bylaw. PERFORMANCE STANDARDS The project can be found to meet the performance standards for the resource areas potentially affected as follows: The project may fit into the regulations as a limited project under 310CMR 10.24 (7)(a) 6. however, the NOI will discuss the project relationship to the performance standards independently. Coastal Banks -Sediment Source Banks (310 CMR 10.30) “WHEN A COASTAL BANK IS DETERMINED TO BE SIGNIFICANT TO STORM DAMAGE PREVENTION AND FLOOD CONTROL BECAUSE IT SUPPLIES SEDIMENT TO COASTAL BEACHES, COASTAL DUNES OR BARRIER BEACHES…..” “No new bulkhead, revetment, seawall, groin or other coastal engineering structure shall be permitted on such a coastal bank except that such a coastal engineering structure shall be permitted when required to prevent storm damage to buildings constructed prior to the effective date…” • The CES at the site has existed for many decades. Restoration and improvement with up- to–date stone setting technique and geotextile are logical necessary activities that will improve the bank and related CES as a vertical storm buffer. The relationship to storm damage prevention and flood control has value and significance for related standards for Land Subject to Coastal Storm Flow and for Coastal Beaches. • The bank is not functioning as a significant sediment source because the overall near- shore areas of Follins Pond are comprised of a glacial ice contact soil and eroding very slowly. From old aerial photographs it appears the site is a filled high marsh area, filled in the late 1950s. Best Available Measures (310 CMR 10.27 & 10.30) The stone revetment system along this shoreline may be deemed a best available measure having been in place for many decades or more. Vertical Storm Buffer (10.30) With the CES in place, the bank is functioning as a vertical storm buffer. 3 “WHEN A COASTAL BANK IS DETERMINED TO BE SIGNIFICANT TO STORM DAMAGE PREVENTION OR FLOOD CONTROL BECAUSE IT IS A VERTICAL STORM BUFFER TO STORM WATERS…..” With respect to the vertical storm-buffer significance of this bank, the proposed project meets the performance standard because it improves bank stability as a storm buffer. “Bulkheads, revetments, seawalls, groins or other coastal engineering structures may be permitted on such a coastal bank except when such bank is significant to storm damage prevention and flood control because it supplies sediment to coastal beaches, coastal dunes and barrier beaches…” The soil type, likely filled land quality, erosion tendencies and long term presence of the stone array cause lower significance of this bank for the listed sediment- based storm-damage prevention interest. Therefore, improvement to the erosion measures is appropriate. Coastal Beaches- 310 CMR 10.27 – The project area is separated from the C. Beach by a strip of Salt Marsh. The Salt Marsh will be protected with a deep-staked silt fence barrier allowing for no contact with the C. Beach The bank stabilizing project activity furthers the interest of storm damage prevention and will not cause for any added detrimental effects to the local environment. The summary relating to Coastal Banks contained in the Yarmouth Regulations appear to mirror those discussed previously under 310 CMR 10. 30. Please refer to the section above relating to the proposed revetment work activity. The stone revetment exists. The re-building of the revetment does not expand its projection in the waterway, allowing the upland to absorb all impacts from the renovation. Salt Marsh and Land Containing Shellfish – The work effort is intended to be out of this resource area however the proximity requires demonstration that performance standards are met. The work area is directly adjacent to the healthy, low Salt Marsh deposit with scant marsh peat but vigorous growth of Spartina alterniflora. Certain shellfish are observed to exist within the salt marsh and beyond further into the pond. The work protocol outlines the method by which the Salt Marsh and Land Containing Shellfish shall be segregated and protected from the work effort. Leaving the existing revetment toe stones in place where practical or replacing them in the same location with methodical management of the silt fence barrier will effectively segregate the activity from the marsh. Yarmouth regulations address Salt Marsh & Land Containing Shellfish performance standards similarly to those of 310 CMR 10.32 & 10.34. The Yarmouth regulations Section 4.06 (3c) speak to restoration and rehabilitation. If the terms restoration rehabilitation relates to rehabilitation of the existing stone array the regulation recognizes the project’s feasibility if the work activity adequately controlled. Salt Ponds – The project is to be physically separated from the Salt Marsh and land Containing Shellfish by a strict work limit however a narrow strip of the existing stone array engages with the Salt Pond high tide line placing the activity marginally within the Salt Pond. 4 The activity will be consistent with the performance standards of 310C MR 10.33: a) water circulation; Being on the immediate shore the replacement revetment will not change water circulation (b) distribution of sediment grain size; No effect to the soil. (c) freshwater inflow; It will not interfere with freshwater inflow. (d) productivity of plants; The project will not adversely impact plant life within the pond (e) water quality; The project will not adversely affect water quality. Land Subject to Coastal Storm Flow Mass. Regulation do not yet regulate LSCSF. Yarmouth regulations can be addressed as follows. 4.10 Land Subject to Coastal Storm Flow Any activity within land subject to coastal storm flowage which will result in the building upon, removing, filling, or altering of land shall not have an adverse effect on the interests protected by the bylaw by: The project does not meaningfully alter the current physical characteristics but rather it provides long term C. Bank stability as a flood buffer i. reducing the ability of the land to absorb and contain flood waters; • The project recovers the ability of the land to absorb and contain flood waters. ii. reducing the ability of the land to buffer more inland areas from flooding and wave damage • The project enhances this ability as stated because it contributes to bank stability. iii. increasing the elevation or velocity of flood waters, or by redirecting or increasing flows or causing channelization: • The project maintains the current physical shape condition iv. causing, or creating the likelihood of, damage to other structures on land within the flood plain as debris (collateral damage); • The project intends to protect the existing structure with no significant change to wave reflectivity in the AE Flood zone v. causing ground, surface or saltate pollution triggered by coastal storm flowage • The project intends to prevent the threat of such outcomes by improving infrastructure stability. vi. reducing the ability of the resource to serve as a wildlife habitat and migration corridor through activities such as, but not limited to the removal of substantial vegetative cover and/or installation of fencing and other structures which prevent wildlife migration across property. • The project does not significantly change the geometry for shore access. The plant strip along the cap will add to vegetive diversity for transiting wildlife. vii. prevention of the migration of resource areas such as salt marshes due to sea level rise. • The existing revetment will not in the near-term permit landward migration of coastal resource areas. Long term with the plausible abandonment of low-lying flood zone land areas, such a revetment will be considered a temporary structure. • The existing features are part of a collection of long existing stone breakwaters and groins, 10 ft. below the velocity flood elevation. The features have been responding to the flood forces delivered to the area for half a century. The repairs will not cause for a significant change to the localized storm action behavior. Flood waters will readily flow over the existing walls. 5 viii. If flood control and storm damage protection functions have already been impaired, redevelopment must improve existing conditions by reducing impervious surfaces, restoring flood control and storm damage protection functions, installing native plantings, o r by restoring or creating other wetland resource areas. Where a previously developed coastal Resource Area has not been regulated under the applicable performance standards to protect the interests of flood control and storm damage prevention, the proposed work shall restore those interests. And shall meet the following requirements; ix. Existing septic system and cesspool repairs will be allowed provided they meet all Title 5 and local Board of Health thresholds. • Not Applicable. x. All groundwater elevations shall incorporate seasonable adjustments if test holes and or leaching components are 100 feet or closer from major estuaries. • Not Applicable. xi. Any proposed deck, shed, or other similar structure must be securely anchored to a footing or foundation. • Not Applicable. xii. Any activity shall preserve existing soils, vegetation, and other natural conditions that serve as buffers to coastal flooding and storm surges. The proposed activity intends to restore and preserve a set of existing conditions of the C. Bank and adjacent resource areas. The long-term existing conditions provided a buffering function to flood waters. APPENDIX TO PROJECT NARRATIVE Construction Guidelines and Work Protocol 85 Merchant Avenue, Yarmouth Port Re-construction of a Stone Revetment August 27, 2026 The following is a guideline to describe the method of construction, material handling, access, equipment type, equipment storage, and schedule related to the proposed delivery of materials and construction of the stone revetment to replace the existing collapsing stone revetment. The project requires strict adherence to a systematic, discreet work process, with a maintained physical barrier from the existing Salt Marsh. The work is repetitive and predictable but the narrow route requires a methodical adherence to the method described. Term of Construction The proposed work should take approximately 4 weeks to complete. The schedule is affected slightly by tides. Very high tides or storms can restrict the work and shall be considered to have only minor effects effect on schedule. Anticipated work activity time is during November thru April, weather permitting, with stone work completion allowing ample time prior to the spring season to plant the upper bank zone prior to the onset of the growing season. Stockpiles and Staging Limited material stockpile and equipment staging shall be within the more open lawn on the side yard of the residence in the general location of the access way indicated on the plan. Stone revetment material quantity must be limited to several day’s supply. Armor stone are not massive and a collection can be stockpiled. Geotextile shall be in tightly bound rolls stored in the upland. Work Access Route The route for hand labor access is via the existing driveway route to the property and to both sides of the house. The machine and material route is the primary route on the right side of the house. Alternate access is gained to the left of the garage. Equipment Equipment utilized is listed as follows: • A rubber track mini excavator, 5 to 6 ft. wide. • Rubber track skid steer or Toro Dingo • Delivery trucks to remain on the street • In conformance with encouraged practice the trucks and machines shall not be allowed to idle unless they are engaged in a direct work effort. • A spill kit managed by the revetment contractor shall be on site and readily accessible during the work term. Construction Procedure First, the site shall be prepared for access. The existing septic system is clear of conflict in the front yard but will be marked. The silt fence barrier shall be installed along the seaward edge of the existing stones. This barrier must be maintained throughout the job. The route to the starting point for new construction on the north end shall be established. The route shall occupy the existing revetment projection and be an excavated earth shelf, approx. 6 ft wide. Two leaning trees, maple and black cherry appear to be causing for slope instability and are intended for removal. The trees will be flagged for the site visit. As the route is contoured, stones encountered shall be controlled either by hand or the excavator bucket and removed from the existing revetment by rotating and placing in a waiting small loader bucket. The revetment shall be built as the excavator backs out by shaping the slope as it goes, with fabric applied, followed by bed stone and armor stone placement. Segments of the proposed revetment will be handled in manageable lengths of approx. 10 ft. The proposed revetment is intended to be placed within the projection of the existing. The work shall proceed from north east to south west to the access point. Minor disassembly of the existing pier is necessary with a less formal rip rap collection placed in that area. The segment utilized for access shall be completed last as the equipment pulls out of the area. The access location remains as a route for restorative work Segments of the stone revetment will be developed as follows: • Existing stone is removed in segments. Where practical the existing toe stones will remain. • The bank shall be contoured where the replacement stone will go. • Board templates shall be erected to assist with shape, elevation, alignment and fit and shall be maintained during the job. • Progress rate will be determined after a day or two of initial work with an estimate of 4 weeks to completion. • During each day the work crew keeps track of all facets, the work limit, the board template alignment, re-use of the existing stone, proper fabric management and building of each segment. • Each 10 ft. revetment segment activity repeats the previous segment activity until the access point is reached. The small machine is the limiting factor for segment length. • All material, the mini-excavator, small loader, and other tools, etc. are removed, the site cleared of any remaining stone pieces. • Access route is examined, loamed as needed, raked out and overseeded with native grass seed. • Vegetation planting activity outlined below, follows within any altered area along the revetment cap where needed as soon as weather permits. Upper slope planting will include native plants. Once the Yarmouth Commission has developed an understanding of the prescribed process, a restoration sketch can be added to the file. The restoration zone is a narrow strip approx. 5 ft. wide along the crest. The revetment work is highly repetitive. A pattern will be established and maintained. Routine job site inspection including elevation confirmation, general construction quality, work practice, material handling shall be a requirement during the work term. Clean Up and Upper Bank Restoration • The 5 ft. planting strip along the top of revetment shall be heavily planted with grasses and several low shrub groupings at a suitable time of year. Native upland seed mix shall be distributed across the slope for added diversity. A sketch of designated plants within the strip will be provided. • The access points shall be inspected. Follow-up inspection follows for a non-specific term to monitor the area.