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FEMA Flood Map API (3.0.0)

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API Support: info@nationalflooddata.com URL: http://nationalflooddata.com/

The FEMA Flood Map API offers up-to-date FEMA flood zone maps and data that can be easily embedded into partners' products or workflow. Our data service is used by insurance companies, appraisers, real estate investors and software companies that offer services to these industries.

We offer the data in the various formats described below to meet a variety of partner use cases. If you have a particular need that you don't see met by the services below, please contact us and we'll likely be able to add what you need.

Authentication

Queries to the v3 API require a key provided by National Flood Data, and the key must be provided in a request header using the key "X-API-KEY". The key cannot be supplied as a parameter, and therefore the API cannot be accessed through a simple web browser. To obtain a key, log-in or register

x-api-key

Required API Key

Security Scheme Type API Key
Header parameter name: x-api-key

Rate Limiting

The v3 API implements a rate limit of four requests per second with a burst limit of three, i.e. at most three requests will be processed simultaneously.

Flood Zones

The core of the FEMA flood maps API is the "flood zone" that is assigned to each region. This value is returned as the fld_zone field from the s_fld_haz_ar layer. Definitions for the zones are below.

Flood Zone Description
A An area with a 1% annual chance of flood; does not have base flood elevations (BFEs) available.
AE An area with a 1% annual chance of flood; base flood elevations BFEs are available.
AH An area with a 1% annual chance of flood with flood depths ranging from 1 to 3 feet, generally near pond or pooling areas. BFEs are available.
AO An area with a 1% annual chance of flood with flood depths ranging from 1 to 3 feet, generally sheet flow on sloping terrain. BFEs are available.
AR An area inundated by flooding, for which BFEs or average depths have been determined. This is an area that was previously, and will again, be protected from the 1% annual chance flood by a Federal flood protection system whose restoration is Federally funded and underway
A1-A30 An area with a 1% annual chance flooding, for which BFEs have been determined.
B, X500 An area with at least a 0.2% chance of annual flood or with a 1% annual chance of flood with average depths less that one foot or with drainage area less than one square mile. (C is the older designation and X500 is the current designation.)
C, X An area outside the 0.2% and 1% annual chance of flood regions. (C is the older designation and X500 is the current designation.)
D An area where flooding is possible but has not been studied.
V An area with a 1% annual chance flooding with velocity hazard due to waves; BFEs have are not available.
VE, V1-V30 An area with a 1% annual chance flooding with velocity hazard due to waves; BFEs have are available.

Base Flood Elevations

bfe_type

The API field bfe_type describes how the base flood elevation for a region was determined.

bfe_type description
provided The base flood elevation is provided by FEMA within the flood zone layer.
matched The base flood elevation is provided by FEMA in an additional later, and that layer only has one base flood elevation transect that intersects the flood zone polygon.
interpolated The base flood elevation is provided by FEMA in an additional later. More than one base flood elevation transect intersects the flood zone polygon, and the closest value of these is used.
extrapolated No base flood elevation is provided by FEMA for the flood zone polygon. A value is extrapolated from neighboring values.

Bodies of Water

The API returns the distance to nearest ten bodies of water. The bodies of water considered are those provided in the USGS National Hydrological Data (NHD) Set with an area greater than 0.25 square kilometers. Streams and not included. The USGS also generally does not include reservoirs, and therefore distance to these are not included.

Key Description
areasqkm area of the polygon in square meters (a body of water may be made of multiple polygons)
distkm distance to the body of water in kilometers
filename name of the file from USGS containing the body of water
gnis_id unique identifier provided by USGS
name name of body of water, generally only available for larger bodies of water
state US state that the body of water is in

Elevation

Elevation in feet. Data provided by USGS. Defaults to -1000000 when not available.

Flood API

Description of our standard data APIs

FEMA Flood Data query

Authorizations:
x-api-key
query Parameters
searchtype
required
string
Enum: "addresscoord" "addressparcel" "coord" "coordparcel" "polygon"

Specification of location type

address
string
Example: address=12 Maple Pl Mapleville KS 12345

address with street number, street type, city, state, zip and without punctuation. Required for searchtypes addresscoord and addressparcel. Do not include 4 digit zipcode extension.

lat
number
Example: lat=34.071783

Location's latitude. Required for searchtype coord

lng
number
Example: lng=-118.2596

Location's longitude. Required for searchtype coord

polygon
string

Polygon in well known text format

loma
boolean
Default: false

Include LOMA updates

elevation
boolean
Default: false

Include Elevation Data (Elevation, BFE, Stormsurge) (Special key required)

property
boolean
Default: false

Include property data (Only for seachtype addressparcel) (Special key required)

parcel
boolean
Default: false

Include parcel data (Special key required)

header Parameters
x-api-key
required
string

API Key needed for authentication

Responses

Request samples 

headers = {'x-api-key':'YOUR KEY'}

# Get data without BFE
payload = {
  'lat': 34.071783,
  'lng': -118.2596,
  'searchtype':'addresscoord',
  'loma': False
}
r = requests.get('https://api.nationalflooddata.com/v3/data', headers=headers, params=payload)

 # Get data with BFE
payload = {
  'address':'430 Australian Ave Palm Beach, FL 33480',
  'searchtype':'addressparcel',
  'loma': False
  'elevation': True
}
r = requests.get('https://api.nationalflooddata.com/v3/data', headers=headers, params=payload)

Response samples

Content type
application/json
{
  • "parceladdress": null,
  • "geocode": {
    },
  • "coords": {
    },
  • "result": {
    },
  • "match_type": null
}

FEMA Flood Data query - batch. Allows for posting a set of data requests, which are processed asynchronously. Poll the url given in the `result` field of response; this will return 200 and a set of results when the batch is completed. A batch may contain up to 20,000 requests.

Request Body schema: application/json
apiKey
string
Array of objects

Responses

Request samples

Content type
application/json
{
  • "apiKey": "string",
  • "requests": [
    ]
}

Response samples

Content type
application/json
{
  • "batch_id": "string",
  • "result": "string"
}

Flood Map Raw

Provides exhaustive flood map data within a determined by user

FEMA Flood Map Raw query

query Parameters
lat
required
number
lng
required
number
size
number
Default: 0.08
Enum: 0.04 0.06 0.08

degree value for size of square that polygons are returned for

geojson
boolean
Default: true

When set to false, geojson content will not be included. The geojson content can be large, so not including it is often faster.

excludex
boolean
Default: true

When set to true, polygons with flood zone (fld_zone) "X" will not be included in the query. This generally makes the response load much smaller and easier to process quickly.

elevation
boolean
Default: false

When set to true, base flood elevations (BFE) will be included in geojson format.

header Parameters
X-API-KEY
required
string

API Key needed for authentication

Responses

Request samples 

headers = {'x-api-key':'YOUR KEY'}
payload = {
  'lat': 34.071783,
  'lng': -118.2596,
  'size': '0.04'
}
s = requests.get('https://api.nationalflooddata.com/floodmapraw', headers=headers, params=payload)

Response samples

Content type
application/json
{
  • "result": {
    }
}

Dynamic Map

How to use the dynamic flood map, i.e. zoom in and out, etc.

The map provided is dynamic, i.e. the user may zoom and pan within a small range.

query Parameters
key
required
string

authentication key

lat
required
number
lng
required
number
zoom
required
integer [ 6 .. 17 ]
Default: 15

integer parameter between 6 (low zoom) and 17 (high zoom).

showLegend
boolean
Default: true

true to show the legend; any other value false.

Responses

Static Map

How to use the static flood map, i.e. to obtain map images in jpg format to embed, for example, in a user report.

The static map returns a png image with a marker at the latitude and longitude provided.

query Parameters
lat
required
number
lng
required
number
Default: 0.08
height
required
integer
width
required
integer
showMarker
required
boolean
Default: true

if marker is set to false, no marker will be shown

showLegend
required
boolean
Default: true

if legend is set to false, no legend will be shown

zoom
required
integer [ 14 .. 16 ]
Default: 15

integer parameter between 14 (low zoom) and 16 (high zoom)

header Parameters
X-API-KEY
required
string

API Key needed for authentication

Responses

Map Tiles

Map tiles as used in the dynamic and static maps.

Flood Vector Tiles

path Parameters
z
required
number
Example: 13

Zoom level of tile

x
required
number
Example: 2043

x coord of tile

y
required
number
Example: 3140

y coord of tile

header Parameters
x-api-key
required
string

API Key needed for authentication

Responses

Request samples 

curl https://api.nationalflooddata.com/v3/tiles/flood-vector/13/2043/3140.mvt -H "x-api-key: <YOUR API KEY>" --output tile.mvt

Response samples

Content type
application/json
{
  • "status": 401,
  • "message": "Unauthorized"
}

Storm Surge Tiles

path Parameters
category
required
string
Enum: "category1" "category2" "category3" "category4" "category5"

category of storm surge for which to retrieve tiles

z
required
number
Example: 13

Zoom level of tile

x
required
number
Example: 2043

x coord of tile

y
required
number
Example: 3140

y coord of tile

header Parameters
x-api-key
required
string

API Key needed for authentication

Responses

Request samples 

curl https://api.nationalflooddata.com/v3/tiles/stormsurge/category1/8/57/101.png -H "x-api-key: <YOUR API KEY>" --output tile.png

Response samples

Content type
application/json
{
  • "status": 401,
  • "message": "Unauthorized"
}