11/13/2025 CONSERVATION COMMISSION Minutes (2)

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Town of Mashpee Conservation Commission 16 Great Neck Road North Mashpee, MA 02649 Additional Plan Refinements: Shed Removal, Stair Removal, and Impact Corrections Several refinements were included beyond those specifically requested by the Commission: • A 105-sq-ft shed along the access path is no longer needed and will be removed, with the area restored to natural conditions. • A 53-sq-ft stairs-and-pad feature along the elevated walkway—previously mentioned verbally but never formally removed—has now been deleted from the plans. During review, BSC discovered a calculation error in the width of a section of elevated walkway connecting to the private way. The walkway had been undercounted by 2 ft 11 in,resulting in an underestimation of—178 sq. ft of buffer-zone impact. Ms. Raddatz emphasized that no physical work changed—only the numerical accounting. The footprint remains exactly as previously shown on the plan. Helical Pile Installation The design now explicitly specifies helical piles (-5.5 in diameter), anticipated to be installed—10 ft deep. Updated structural information and an expanded scope letter were submitted in detail. Impact Totals, Mitigation Plan, and Restoration Ratios After revising impacts to incorporate the walkway correction and updated features, Ms. Raddatz reported: • Largest individual buffer-zone impact: 568 sq. ft • Mitigation plantings: 3,332 sq. ft • Restoration area (including shed removal): 1,436 sq. ft • Total mitigation+restoration: 4,768 sq. ft • Mitigation ratio: Greater than 8:1 relative to the increased impacts She noted that the site contains overlapping buffer zones (coastal dune, coastal bank, LSCSF), so some areas count multiple times for regulatory impact analysis. Flood-Resilient Design, Dune Improvement, and ASCE 24 Compliance All proposed structures—the tent deck and walkways—will be elevated, improving dune conditions by reducing shading and restoring areas previously covered by the existing tent complex. Ms. Raddatz relayed updated engineering notes confirming that the entire elevated structure meets ASCE 24 flood-resilience requirements. Under Section 9.2 of that standard, detached decks in flood zones must either be engineered to remain intact during a base flood event or designed as breakaway structures. The applicant has chosen the breakaway design, allowing the deck to fail in a controlled manner to protect the Popponesset Inn during a severe flood. Design assumptions incorporate: • Base Flood Elevation: 12 ft • Additional assumed dune scour: 1.5 ft Thus, the structural design accounts for both water elevation and potential lowering of dune surface during storm events. 9