Flood Zones in Hornell: The Canisteo River, the Levees, and What Buyers Should Check

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Last reviewed: October 9, 2026. General information only, not engineering, insurance, or legal advice. Flood maps, insurance rules, and local regulations change. Check the current FEMA map for the specific address and talk to the City’s floodplain administrator and a licensed insurance agent before you buy or build.

Hornell sits where Canacadea Creek meets the Canisteo River, with Crosby Creek and Chauncey Run running through town. That geography is a big part of the city’s history, and it’s why Hornell is ringed by levees and concrete floodwalls that many residents drive past every day without a second thought. If you’re buying here, flooding deserves a careful look. The question isn’t only “is it in a flood zone?” It’s also how the flood protection system works, what the maps do and don’t show, and what’s actually covered by insurance.

A short history: why the levees are there

A 2002 flood mitigation plan prepared for the City of Hornell, the Village of North Hornell, and the Town of Hornellsville (published by the Southern Tier Central Regional Planning and Development Board) lays out the area’s flood history. Two events stand out:

  • July 1935. The plan calls this the flood of record for the Canisteo River and Canacadea Creek in the Hornell area. A large part of the city was underwater, and residents were evacuated to the Hornell Armory.
  • June 1972, Tropical Storm Agnes. Not the flood of record, but according to the plan the most severe flood in recent memory. Hundreds of homes in all areas of the city were evacuated. The plan notes that most of Hornell’s damage came from basement flooding and erosion, including groundwater and surface water seeping into basements and runoff that ponded behind the levees because it couldn’t drain into the swollen river.

The plan lists other notable events too, including August 1984 thunderstorms. In Hornell that year, most of the damage came from water percolating through cellar walls rather than from surface flooding, and for that reason it didn’t qualify for federal disaster assistance.

The flood protection system

After 1935, the federal government built a comprehensive flood control plan for southern New York. The New York State Department of Environmental Conservation’s Hornell Flood Damage Reduction Project fact sheet describes the Hornell works:

  • About 31,300 feet of earth levees and 27,700 feet of concrete wall
  • 19,600 feet of channel realignment and 10,550 feet of channel paving
  • Replacement of 7 bridges and modification of 6 more, plus check dams, drop structures, weirs, closure structures, and drainage structures along the Canisteo River, Canacadea and Crosby Creeks, and Chauncey Run

Two upstream reservoirs are part of the plan: Arkport Dam on the Canisteo River and Almond Lake on Canacadea Creek. According to the 2002 plan, together they control 56% of the Canisteo River watershed above the city. DEC’s fact sheet says the system was designed to protect Hornell against discharges roughly double those of the July 1935 flood, and that the protective works withstood the 1972 Agnes flood, the maximum of record on the Canisteo River. The levees and walls are operated and maintained by the U.S. Army Corps of Engineers and DEC.

What the levees don’t do

Flood protection reduces risk. It doesn’t remove it. The 2002 plan is candid about the problems that remain:

  • Interior drainage and ponding. When the river is high, rain falling on the protected side can pond behind the levees.
  • Groundwater and basements. Shallow groundwater and seepage into basements are a recurring theme in the plan’s account of past floods.
  • Smaller streams and steep drainage ways. The plan notes that many smaller streams in the area are steep and prone to flash flooding. In the Town of Hornellsville, some weren’t studied when the flood maps were made, so they have no mapped floodplain even though they can flood.
  • Maps assume everything works. The plan explains that the flood maps assume channels and drainage structures remain unobstructed and operate properly. If they don’t, a 100-year flood could be worse than mapped.

Step 1: Look up the address on FEMA’s flood map

Start with the FEMA Flood Map Service Center. Search the address and open the current effective Flood Insurance Rate Map (FIRM). You’re looking for:

  • Special Flood Hazard Area (SFHA): zones beginning with A (such as A or AE). This is the “100-year floodplain,” the area with a 1% chance of flooding in any year.
  • Moderate-risk area: shaded Zone X, often called the “500-year floodplain” (0.2% annual chance).
  • Floodway: the channel and adjacent land kept clear to carry floodwater. Development rules are strictest here.
  • Areas behind levees: map notes may indicate areas protected by an accredited levee. Read the panel notes and legend, not just the color.

If the property is close to a boundary, don’t eyeball it. Ask City Hall who serves as the floodplain administrator, and how they read the map, and ask the seller whether there’s an elevation certificate.

Step 2: Read the seller’s flood disclosures

New York’s Property Condition Disclosure Statement changed on March 20, 2024. Sellers of most residential property can no longer skip the form by giving the buyer a $500 credit at closing, and the form now includes flood questions. According to the New York State Bar Association’s summary, the new questions ask whether:

  • any or all of the property is in a FEMA-designated floodplain;
  • the property is in the special flood hazard area (100-year floodplain) or a moderate flood hazard area (500-year floodplain);
  • the property is subject to a requirement for flood insurance;
  • the seller has received FEMA, SBA, or other federal disaster assistance for flood damage;
  • there is flood insurance on the property or a FEMA elevation certificate; and
  • the seller has ever filed a flood damage claim with any insurance provider.

Read those answers carefully, and ask follow-up questions about basement water. A “no” to the floodplain questions doesn’t mean the basement stays dry. The 1972 and 1984 experiences described above show that much of Hornell’s flood damage has come from seepage and ponding, not from mapped river flooding.

Step 3: Understand the insurance rules

Standard homeowners policies generally don’t cover flood damage. FEMA’s flood insurance page says most homeowners insurance doesn’t cover floods, and that flood insurance is a separate policy available in communities that participate in the National Flood Insurance Program (NFIP). According to the 2002 plan, the City of Hornell and the Town of Hornellsville joined the NFIP in 1980, and the Village of North Hornell joined in 1996.

  • Mandatory purchase: FEMA says homes and businesses in high-risk flood areas with mortgages from government-backed lenders are required to have flood insurance. If the house is in an SFHA, expect your lender to require it.
  • Waiting period: FEMA says there’s typically a 30-day waiting period before an NFIP policy takes effect, with exceptions such as coverage required in connection with a loan. Don’t wait until the river is rising.
  • Basements: NFIP coverage in basements is limited. FloodSmart’s basement coverage explanation is worth reading before you finish a basement or store belongings there.
  • Outside the mapped zone: flood insurance is available outside high-risk areas as well. Ask an agent for a quote whatever the map shows, especially for homes in low spots, near creeks, or with a history of basement water.

Ask your insurance agent separately about sewer backup and groundwater seepage. Those are usually treated differently from flood and may need an endorsement on your homeowners policy, if they’re available at all.

Step 4: Plan any work with the floodplain rules in mind

The City regulates development in the mapped floodplain under Chapter 154, Flood Damage Prevention, of the city code, adopted by the Common Council in 1989. Southern Tier Central’s floodplain development permit checklist explains how the process typically works in the region:

  • A floodplain development permit is required for any development in the regulated floodplain. That includes building, renovating, repairing, or expanding structures, as well as fill, grading, excavation, paving, and utilities.
  • Permits from other agencies don’t replace the municipal floodplain permit.
  • An elevation certificate or floodproofing certificate is required for any new or substantially improved building.
  • Where a Base Flood Elevation is available, the checklist states that the required flood protection level is two feet above it.

This matters if you’re buying an older house in a mapped zone and planning a major renovation. Large projects can trigger “substantial improvement” rules that require bringing the building into compliance, often by elevating it or its utilities. Talk to the floodplain administrator before you buy if a big renovation is part of your plan.

Practical steps for any Hornell house

  1. Look up the address on FEMA’s Flood Map Service Center and save a copy of the map panel.
  2. Read the flood questions on the seller’s Property Condition Disclosure Statement and ask for any elevation certificate.
  3. During your inspection, look for basement water signs: efflorescence, staining, a sump pump (and how often it runs), and stored items raised off the floor.
  4. Get a flood insurance quote whatever the zone, and ask about sewer backup coverage.
  5. Check gutters, downspouts, and grading. Many basement problems are drainage problems.
  6. If you’re planning renovations, talk to the City about floodplain permits first.
  7. Sign up for local emergency alerts and know where the National Weather Service issues flood warnings for the Canisteo River.

Frequently asked questions

If the house is protected by the levee, do I need flood insurance?

It depends on how the property is mapped and what your lender requires. Being behind a levee lowers risk but doesn’t eliminate it. The levee protects against river flooding up to its design level, but not against interior ponding, seepage, or flash flooding on small streams. Get a quote and decide with your agent.

Is the 2002 plan still current?

The 2002 plan is useful for history and for how the system works, but it’s not the latest planning document. The City’s website links to the current Steuben County Multi-Jurisdictional Hazard Mitigation Plan. Always use the current FEMA map for the address.

Official sources

Related: Buying an older home in Hornell · Hornell property taxes and assessments

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