Engineers present three options to reduce Ellicott Creek flooding; board to seek permits and funding

Kevin Miller, a water-resources engineer with Gomez and Sullivan Engineers, presented a draft flood‑mitigation study for Ellicott Creek to the Village of Williamsville Village Board on May 27, outlining three design alternatives, cost estimates and next steps.

The study modeled ‘‘existing conditions’’ as the dam and gates operating as originally intended rather than the dam’s current state, Miller said. ‘‘For this study, existing conditions is the dam in place with its gates in place operating as they were intended to, not the current state of the dam as you look at it today with the gates removed,’’ he said. The hydrologic analysis used a combined 1D/2D model and included flows from low conditions up to a 500‑year recurrence interval; Miller noted the 100‑year recurrence interval is the typical FEMA benchmark for floodplain mapping.

Miller described three alternatives analyzed in the report and provided order‑of‑magnitude costs: replacing the gates with an automated crest‑gate system (alternative 1), estimated at about $1.2 million; removing the existing Williamsville Dam and constructing a new low weir upstream with excavation of the West Channel (alternative 2), estimated at roughly $700,000; and alternative 3, which adds a 40‑foot‑wide flood bench on the East Channel to alternative 2, estimated at about $1.3 million. He said the alternatives reduce the chance of gate misoperation and debris build‑up and have ‘‘similar flood inundation extents’’ but produce less than half a foot (about 0.4 feet) of upstream water‑level reduction under the modeled events.

Board members and staff questioned technical and practical details. Questions included whether ‘‘existing conditions’’ in the model assumed gates in service (Miller confirmed it did), expected excavation depths in the West Channel (Miller said portions might require about 3 feet of excavation but that depth varies across the reach), whether excavated stone could be reused for nearby Local Waterfront Revitalization Program (LWRP) projects (Miller said placement of material in the floodway would require ‘‘a no‑rise analysis’’ and regulatory review), and whether construction staging would close park access (Miller said staging and access effects would be addressed in a later design phase).

Citizens at the meeting raised technical and policy concerns. Dr. Gregory Phillips highlighted bedrock underlying the West Channel and warned that reaching the East Channel elevation may require blasting; he asked how far below the silt the Onondaga limestone extends. Resident Lauren Rybicki asked about contaminant testing and who would pay for removal and disposal if contaminated material is encountered; Miller said contaminant testing would be part of the design phase and that testing is required to determine next steps. Other residents urged the board to pursue regional funding sources, noting programs such as the Consolidated Funding Application (CFA), Resilient New York, Environmental Facilities Corporation (EFC) grants and funding tied to the Niagara Power Project relicensing.

Mayor Hunt told speakers the board would share the study with neighboring jurisdictions and pursue funding opportunities. ‘‘We will be sharing it with Amherst. We will be looking at funding. As soon as we have everything in place, then we will be able to seek funding,’’ Mayor Hunt said. No formal vote or commitment to a preferred alternative was taken at the meeting; Miller said the study recommended alternative 2 as ‘‘the best combination of upfront cost, flood reduction benefit, and long term operations and maintenance responsibilities,’’ but he also outlined required next steps: engineering design, permit applications and identification of funding, including potential benefit‑cost analyses for some grants.

The presentation and public comments highlighted limits of the modeled benefits: although water levels drop modestly under the alternatives, Miller said the changes produce ‘‘not really reduc[ed] the footprint very significantly of where the water stands.’’ He also said that because another dam (Cline Dam) had been removed earlier in the decade, mill operations in the reach would not be restored under any of the modeled scenarios.

The board directed staff to compile the report materials and to continue outreach with Amherst and other regional partners as the village evaluates funding and permitting pathways. The board did not adopt a specific project or budget at this meeting; any design or construction would require further engineering, regulatory approvals and identified funding sources.

For now, the study provides technical comparisons of three paths forward, each with trade‑offs among construction cost, long‑term maintenance and modest modeled reductions in upstream water levels. Public speakers urged the board to pursue regional grant programs and to consider environmental and property‑rights questions raised during the session.