Ithaca council approves $50,000 from stormwater fund to pursue FEMA map revisions

The Ithaca Common Council on April 2 voted unanimously to transfer $50,000 from the city's stormwater fund to pay consultants working to revise federal flood-mapping models that officials say overstate local flood risk.

City officials said the work will support a Letter of Map Revision (LOMR) request to the Federal Emergency Management Agency (FEMA). The move is part of a broader response after FEMA issued preliminary flood maps that, city consultants have said, are more conservative than University of the U.S. Geological Survey (USGS) modeling the city commissioned.

The council's authorization came after a detailed briefing from Mike Thorne, superintendent of public works, and Tim Logue, director of engineering, who described a multiyear sequence of studies, FEMA draft maps and grant work. Thorne traced the history: Ithaca began a local flood-hazard analysis in 2015, hired USGS for field-based modeling, then contracted engineering firm Barton & Loguidice to analyze mitigation options. FEMA issued draft maps in 2022 and preliminary maps in 2023; Barton & Loguidice later identified several technical differences between FEMA's models and the city's that, officials say, make FEMA's estimates overly conservative.

Thorne said the consultant work will examine five technical issues in FEMA's modeling, including available surveyed channel geometry, peak-flow estimations and the assumptions FEMA used for lake level during a storm. "We have very strong arguments" on several of those items, Thorne told council, adding that the firm will model each issue separately and then submit the work to FEMA.

City staff and consultants stressed urgency because the FEMA maps are slated to become regulatory in mid-June 2025. Under FEMA policy, properties newly placed in the regulated floodplain may become eligible for mandatory federal flood insurance purchase for federally backed mortgages; staff cited wide potential variability in individual insurance costs. Councilmembers and staff discussed how the city's planned mitigation measures ' dredging by the New York State Department of Environmental Conservation (DEC) and locally built channel improvements and flood walls ' would interact with FEMA's rules and with grant funding the city has received for design work under Hazard Mitigation Grant Program (HMGP) awards.

Thorne told council the city applied earlier for $12 million under FEMA HMGP and received a phased award (about $800,000 for design/analysis to date). He said FEMA requires the city to demonstrate that a mitigation design based on FEMA's models will work before releasing later-phase construction funds; the city is seeking to show that the FEMA models can be refined so the mitigation work is feasible and that grant funds can be used efficiently.

Councilmember questions addressed the expected scope of properties affected by the maps, timing and whether federal representatives could help. Thorne and city staff said the earlier 1981 FEMA maps affected roughly 80 properties; the new FEMA and USGS maps cover more than 1,200 properties in some scenarios. Thorne said a combination of dredging and structural mitigation in channels could substantially reduce the number of properties in mapped floodplains, but the technical modeling and FEMA review are necessary to confirm that.

The council approved the $50,000 transfer from the stormwater fund balance (staff said the fund's unaudited balance is approximately $1.4 million) and asked staff to continue briefings. Councilmembers also discussed outreach and the need to explain timing and insurance consequences to residents.

The city manager and staff said they will share additional documentation with council members and pursue expedited FEMA review if possible; staff noted FEMA indicated it would try to expedite a technical review if a formal LOMR is submitted.

Ending: City staff said Barton & Loguidice will refine technical analyses over the coming months and submit a LOMR package to FEMA; councilmembers asked for continued updates and for planning-department information about insurance implications and the community rating system at a future meeting.