Form RP-6371-APP: Lake Ontario and Connected Waterways Assessment Relief Application Explained

Form RP-6371-APP, issued by the New York State Department of Taxation and Finance, gives property owners along Lake Ontario and its connected waterways a way to ask their local assessor for a reduction in assessed value when flooding, erosion, or high water levels have damaged their land or structures. The form is tied to the Lake Ontario and Connected Waterways Assessment Relief Act, a state law created after repeated flooding events left waterfront property owners paying taxes on assessments that no longer reflected the real condition or value of their property.

The idea behind the form is fairly straightforward. If your property sits along Lake Ontario, the St. Lawrence River, or another connected waterway, and it suffered physical damage or lost value because of high water levels, you can use RP-6371-APP to formally request that the assessor lower the assessment for the affected tax year. This isn’t an automatic adjustment — the property owner has to apply, document the damage, and make the case to the assessor directly.

Who Needs to File This Form

This application is meant for owners of residential, seasonal, or commercial property located on or near Lake Ontario and the waterways legally connected to it under the relief act. If your property experienced flooding, shoreline erosion, structural damage, or a documented loss in usability tied to lake levels, you’re a likely candidate. Landlords, seasonal cottage owners, and year-round residents along the affected shoreline have all used this form when their property’s condition changed significantly due to water damage but the assessed value on record didn’t reflect that change.

It’s worth noting this form applies specifically to the assessment relief process — it’s separate from disaster-related exemptions covered elsewhere, such as the relief available under Form RP-5850 for Superstorm Sandy exemptions, which addresses a different storm event and a different legal basis for relief.

When to Use RP-6371-APP

The application needs to be submitted to the local assessor within the time frame set by the relief act, generally tied to the assessment year in which the damage occurred. Because flooding events along Lake Ontario have happened in multiple years, the exact filing window can shift depending on when the qualifying high-water event took place. Property owners should check with their town or city assessor’s office to confirm the current filing deadline before submitting, since missing the window can mean waiting for the next assessment cycle.

What the Form Requires

RP-6371-APP asks for basic identifying information about the property — the parcel address, tax map number, and owner details — along with a description of the damage and how it affects the property’s value. Owners typically need to attach supporting documentation, such as photos of flood or erosion damage, repair estimates, insurance claims, or any official reports from local emergency management agencies confirming the water event. The more concrete evidence you provide, the easier it is for the assessor to evaluate the claim.

Since this is a fillable PDF (AcroForm), you can complete it directly on a computer using a PDF reader that supports form fields, then print it for signature and mailing, or submit it according to your local assessor’s preferred method. Some assessors accept digital submission by email; others require a physical copy with an original signature, so it’s a good idea to call ahead and confirm.

What Happens After You File

Once submitted, the assessor reviews the application and supporting evidence, then decides whether to adjust the assessment. If the assessor denies the request or you disagree with the adjusted amount, there’s a separate process for disputing that decision — this is where Form RP-6371-BAR comes in, allowing property owners to file a formal complaint with the Board of Assessment Review specifically under the Lake Ontario relief act.

Property owners dealing with other assessment roll corrections unrelated to flooding, such as errors on a village tax roll, would instead look at a form like RP-554-V, which handles a different kind of correction process entirely.

Because assessment relief tied to natural disasters often comes with strict local deadlines and varying documentation standards, it’s worth reaching out to your assessor’s office directly before filing RP-6371-APP to confirm exactly what they need and by when.