Frequently Asked Questions


Why should I care about floods?

Myths and Facts about Flood Insurance

Myth: Federal Disaster Assistance Will Rebuild my House after a Flood

Fact: disaster funds are only available when there’s a presidential disaster declaration and it is usually a loan you have to repay with interest. With flood insurance on the other hand, your claims are covered (up to a limit) regardless of whether there’s been a presidential disaster declaration (and you don’t have to repay them).

Myth: My house is on high ground so I’m not at risk of a flood

Fact: floods can be caused by several conditions, for example heavy rains, clogged drains, melting snow, failed levees, etc.

Myth: I live outside of a FEMA flood zone

Fact: Flood risk exists everywhere. FEMA maps aim to delineate high risk areas but they are often outdated and inaccurate. Approximately 30% of flood claims come from moderate and low risk areas.

Myth: 100 year flood = 1 flood every 100 years

Fact: there’s a 26% chance you will experience a “100 year flood” during the life of your mortgage. Also, 100-year floods can happen 2 years in a row.

Myth: I live outside of a FEMA flood zone

Fact: Flood risk exists everywhere. FEMA maps aim to delineate high risk areas but they are often outdated and inaccurate. Approximately 30% of flood claims come from moderate and low risk areas.

The “100 year Floodplain”

What is the 100-year flood a.k.a. floodplain, 1% annual chance flood?

The term 100-year flood is used to describe high-risk flood zones. A high-risk flood zone is an area of land that has a 1 percent chance of flooding in any year. This does not mean a flood that happens once every 100 years.

The Flood Insurance Rate Maps (FIRMs) use the 100-year flood event as a measure.

For example, in some areas in Florida, this measurement is equivalent to 10 inches of rainfall in a 24-hour period.

According to national statistics, you have a 25 percent chance of flooding and a 4 percent chance of a fire in a 30-year time period.

What is the 100 year floodplain used for?

The 100 year floodplain is used by many stakeholders. Here are a couple of examples:

  • Communities use maps called the Flood Insurance Rate Maps (FIRM), depicting the 100 year floodplains, to regulate development in areas that are subject to high flood risk.
  • Banks and Insurance providers use 100 year floodplains in the FIRMs to determine whether a homeowner is required to purchase flood insurance.

Is the 100 year floodplain accurate?

There is no 100% certainty associated to the 100 year floodplain because it is the result of data and computations that carry uncertainty (error). This means floodplain boundary or a Base Flood Elevation (BFE) can be off by several feet at a time.

Here are some sources of uncertainty (error):

  • 100 year floodplains are based on past data, without recent or future considerations. The computations tend to look at events that occurred in the past and may not even include recent events. Very recent events or future considerations (e.g., climate change, sea level rise, flood control structures that are in construction, etc.) tend to not be included in the FIRMs. For example, the 100 year floodplains depicted in the new maps issued for the East Coast of the US donot include Superstorm Sandy as part of the computations.
  • The past records are limited. The river/coastal flow estimations depend on gages that record how high and how much water flows at certain points in time. However we only have up to 150 years of record, and in some areas much less. This span of time is insufficient to produce “100 year flood” estimates closer to 100% certainty.
  • The computations carry an uncertainty. The methodologies/models that are used to estimate water flows and elevations carry their own uncertainty, so much that two competent engineers/scientists could arrive at different yet valid results, using the same data.

I’ve never been flooded so I’m not at risk, right?

Wrong! even if your home has never been flooded, you still have a high probability of being flooded during a “100 year flood.” Consider these two facts:

During the span of a 30-year mortgage, a home in the 100-year floodplain has a 26-percent chance of being flooded at least once during those 30 years!


That is a 1 in 4 chance of being flooded during the life of your mortgage!

100-year floods can happen 2 years in a row


Yes, 100 year floods can happen more than once in 100 years! Therefore, we shouldn’t even call it the “100 year flood.” The USGS advocates for calling it “1 percent annual exceedance probability flood”

I’m more worried about other risks affecting my property, so why focusing on this?

Because flooding is the top natural risk for a property! Just see how flood risk is compared to other risks:



% chance of happening during the next year

25-year flood

4 chances in 100

Involved in a

car accident

3 chances in 100

Some form of cancer

3 chances in 100

Victim of larceny

2 chances in 100

50-year flood

2 chances in 100

Victim of burglary

1 chance in 100

Injured in a car accident

1 chance in 100

100-year flood

1 chance in 100

Victim of auto theft

1 chance in 300

Victim of

aggravated assault

1 chance in 500

Victim of robbery

1 chance in 1,000

Residential fire

4 chances in 10,000

Killed in car accident

3 chances in 10,000

Source: Floods and Your Family brochure, U.S. Army Corps of Engineers

Think about it: your property is much more likely to be subject to a flood than to have a residential fire.

Flood Risks and Zones

​Flood maps refer to areas of high, medium or low risk as “flood hazard zones” and the zones of  highest risk as “Special Flood Hazard Areas” (SFHA) where insurance is mandatory.

High flood risk

AE, A, AH or AO Zone. These properties have a 1 percent chance of flooding in any  year – and a 26 percent chance of flooding over the life of a 30-year mortgage.

VE or V Zone. These properties have a 1 percent chance of flooding in any year and also face hazards associated with coastal storm waves.

Insurance note: High-risk areas are called Special Flood Hazard Areas, and flood insurance is required for loans provided by federally regulated lenders as well as Government Sponsored Enterprises such as Freddie Mac and Fannie Mae.

Low or moderate flood risk

Flood insurance is optional, but recommended. The risk is reduced, not removed. Flood insurance can still be obtained, and at lower rates. ~30 percent of all flood insurance claims come from low to moderate risk areas.

Conversion offers savings. An existing policy can be converted to a lower-cost Preferred Risk Policy for those properties that qualify.

Hurricane Evacuation Zones

Hurricane evacuation zones (e.g., A, B, C) are not the same as FEMA Flood Hazard Zones. They are determined very differently and have different meaning. Flooding can occur anywhere because of low areas, bodies of water and the way water runs off land. But all of these areas might not be in a hurricane evacuation zone because of their distance from the coast and other factors.

Property Elevations

It is important to understand the elevations that your property has in relation to the adjacent ground and the FEMA Base Flood Elevation. This matters because your property’s insurance premium will be rated according to these elevations. They are often measured by Registered Land Surveyors.


Base Flood Elevation (BFE)

The BFE is the elevation that the water will reach during the 100 year flood. It is shown on the Flood Insurance Rate Map (FIRM) for Zones AE, AH, A1-30, or VE.

Lowest Adjacent Grade (LAG)

The LAG is the elevation of the lowest ground touching the structure. This elevation is used for several purposes. For example, if the LAG of your property is above the BFE, this means that your property is “above” the 100 year flood. If this is the case, you can ask FEMA through a Letter of Map Amendment (LOMA) to remove the mandatory insurance requirement.

Lowest Floor Elevation (LFE)

The LFE is the lowest floor of the lowest enclosed area (including basements), except for unfinished or flood-resistant enclosures used solely for parking of vehicles, building access, or storage. It is used to determine flood insurance rates.

For properties located in A Zones, FEMA requires to elevate the top of lowest floor to or above BFE; and in V Zones to elevate the bottom of lowest horizontal structural member to or above BFE.


The freeboard is the distance between the BFE and the LFE. Communities often require an specific freeboard as a factor of safety. For example Florida building code requires the LFE to be at least 1 ft. above the BFE while New York City code requires a freeboard of 2 ft. single and two- family residences and 1 ft. for most other buildings.

Beyond Floods Algorithm and Sources

What is the Flood Outlook Score?

The Flood Outlook Score is an abstraction of more than 25 factors that affect, and are the result of, real estate, social perception, flood insurance, flood mitigation and losses, infrastructure, and geomorphology. This score considers past, present, and future scenarios, including impact due to sea level rise. The higher the score, the more resilient the property is to the effects of flood hazards.

What are the sources used to create the Flood Outlook Score and to populate the detailed reports?

We have gone beyond the traditional FEMA flood hazard data (e.g., National Flood Hazard Layer [NFHL]) to assess flood hazard impact  both inside and outside the FEMA Special Flood Hazard Area (SFHA) using best available data. Here is a non-exhaustive list of data sources used by our algorithm:

  • NYC DoITT. We leverage building footprints and the NYC PLUTO database
  • NYC high resolution  topographic data (LiDAR)
  • US Census Bureau – 113th Congress Census Release
  • Coastal Flood Loss Atlas Storm Surge by Hurricane Category
  • FEMA Digital Flood Insurance Rate Maps (FIRMs) (current and upcoming)
  • FEMA Coordinated Needs Management Strategy (CNMS) Dataset
  • FEMA Community Rating System (CRS) Listing
  • FEMA Disaster Declarations Summary
  • FEMA Individual Assistance (IA) Data
  • FEMA Geoplatform for National Flood Insurance Program (NFIP) Data
  • FEMA Community Data on NFIP Participation, policy penetration and claims history
  • Home Mortgage Disclosure Act (HMDA) Data
  • USACE’s National Levee Database
  • US Fish and Wildlife Service’s National Wetland Inventory
  • NYC Selected Facilities Sites
  • USGS Watershed Boundary Dataset
  • NOAA Sea Level Rise Estimates for Future Conditions
  • Florida Department of Revenue Tax Rolls
  • Local Property Appraiser data

How do you estimate the Insurance Premium for a property?

The table below categorizes the sources and assumptions made for the different supported areas:




FEMA Insurance Rating Guidance

NFIP Flood Insurance Manual – June 2014, Revised October 2014. NFIP Specific Rating Guidelines – October 2014.

NFIP Flood Insurance Manual – June 2014, Revised October 2014. NFIP Specific Rating Guidelines – October 2014.

NFIP Flood Zone

Preliminary County DFIRM – 1/30/2015

Effective County DFIRM – 2/4/2015

Base Flood Elevation

Preliminary County DFIRM – 1/30/2015, or approximated using related high resolution elevation data.

Effective County DFIRM – 2/4/2015, or approximated using best available elevation data.

Elevation Certificate

Assumes all homeowners have an EC.

Assumes all homeowners have an EC.

Information about your Home:

• Assessed Value

• Elevation

• Floors

• Foundation

• Location of Contents

• Area of Crawlspace or Enclosure on which the house is elevated

Derived from New York City Tax Assessor’s Database information when possible.

• Foundations assumed to be slab on grade, no basement.

• Contents assumed to be evenly distributed throughout floors.

• Assumes presence of utilities / appliances on lowest floor.

Derived from Miami-Dade County Tax Assessor’s Database information when possible.

• Foundations assumed to be slab on grade, no basement.

• Contents assumed to be evenly distributed throughout floors.

• Assumes presence of utilities / appliances on lowest floor.

Coverage Amounts

Set to cover structures fully, up to the available NFIP maximums.

Set to cover structures fully, up to the available NFIP maximums.


Set to minimum available – $1000/$1000.

Set to minimum available – $1000/$1000.

Beyond Floods App Help

The information below will give you an overview of the Beyond Floods App and how it can be of help to you. If you have unanswered questions, please e-mail us at

Location Search Bar

Type any property address, zip or neighborhood name here to retrieve Flood Outlook data.

Search Results

This app screen provides a flood outlook summary for the location searched at a property- and neighborhood- level.

Interactive Map

This app screen provides an interactive map with markers identifying search results and other useful map layers to provide perspective regarding the location searched. Zoom in closer to view satellite imagery.

Reload the Beyond Floods App from the Under the Hood  screen to unlock additional map features after you have made an In-App Purchase.

Full Flood Outlook Report

This app screen provides you detailed flood outlook reports at a property level (accessible after purchasing a one-time 3-month subscription for $4.99) and at a neighborhood level (accessible with the free app).

Under the Hood

This app screen provides you with some options to customize the Beyond Floods app (e.g. Default City for Search Results), to access status of In-App Purchases, and to view our Terms of Service and Privacy Policy.

I know and understand my risk. Now what?

TAKE ACTION! you have the power and responsibility to be prepared and mitigate your property risk! Here are some common questions that show you ways in which you can do it. Contact us if you are interested in accomplishing them:

I got a letter from my bank saying that I’m required to have insurance, but my Beyond Floods detailed report says it’s only Recommended/Optional. What can I do?

Obtain a Flood Determination Form. This is an official FEMA form that is used to communicate banks and insurance companies the basics of the flood hazards your property is subject to, according to official maps. It basically puts the information we provide you in the detailed report, in a form your bank or insurance agent can use to make decisions.

Bank and Beyond Floods detailed report tell me I have to purchase flood insurance,  however, I’ve never been flooded and I know I’m above the Base Flood Elevation. What can I do?

A. Obtain an Elevation Certificate. This is a FEMA form completed by licensed surveyor who performs detailed measurements at your property. Often required for purchasing flood insurance, appealing a determination, or required by building codes in certain locales. This form will tell you if your property is above the BFE or not.

B1. If your property at or above the BFE, apply for a LOMA. The Elevation Certificate forms the basis of a Letter of Map Amendment (LOMA) that can help correct it inaccuracies in FEMA maps and make flood insurance purchase optional. Furthermore, it allows you to access low risk premiums should you want to purchase flood insurance.

B2. If your property is below the BFE, purchase Flood Insurance. Having an Elevation Certificate ensures that you will have the best possible rate.

My case is not listed here. What can I do?

You can email us at We are passionate about flood risk and our team of experts would love to hear your case.