Flood Service

The Location Hub® Flood Service processes geographic coordinates and quickly evaluates whether an address (or coordinate location) is inside a flood hazard return period, including River Flood (Fluvial), Surface Water (Pluvial), Storm Surge, and/or Defended Areas.

The Flood Service supports the following return periods only: OneIn20Years, OneIn50Years, OneIn75Years, OneIn100Years, OneIn200Years, OneIn500Years, OneIn1500Years, SurfaceWaterOneIn20Years, SurfaceWaterOneIn50Years, SurfaceWaterOneIn75Years, SurfaceWaterOneIn100Years, SurfaceWaterOneIn200Years, SurfaceWaterOneIn500Years, SurfaceWaterOneIn1500Years, StormSurgeOneIn20Years, StormSurgeOneIn50Years, StormSurgeOneIn75Years, StormSurgeOneIn100Years, StormSurgeOneIn200Years, StormSurgeOneIn500Years, StormSurgeOneIn1500Years

What does it do?

The Flood Service allows users to determine whether or not a property is within a flood risk area or defended area based on a defined return period by passing a geographic coordinate of the location to the service. Input coordinates must be in Latitude and Longitude WGS84 projection.

The Flood Indication service quickly returns True or False if the coordinate falls within the maximum flood extent of the 1 in 1,500 year return period for either River Flood, Surface Water and/or Storm Surge. The Flood Evaluation service allows the user to specify the flood return period to be queried and the service returns the flood depth at the location, if the coordinate is within the extent. The Defended Area service returns the Standard of Protection (SoP) and the accuracy Level of the defended area polygon.

Flood Service – SOAP Interface

The SOAP Interface provides access to the following web service requests:

Flood Service – REST Interface

The REST API Interface provides access to the following web service requests:

Flood Service – Return Periods

The following Flood Return Periods are available in the Flood Evaluation Service for River Flood, Surface Water and Storm Surge:

  • 1 in 20 year
  • 1 in 50 year
  • 1 in 75 year
  • 1 in 100 year
  • 1 in 200 year
  • 1 in 500 year
  • 1 in 1,500 year

Flood Service – Depth Levels

The following depth levels are returned by the Flood Evaluation Service for River Flood, Surface Water and Storm Surge:

1 x <= 0.3m
2 0.3 < x <= 1m
3 1 < x <= 3m
4 3 < x <= 6m
5 6 < x <= 9m
6 x > 9m
127 No Data Found

Flood Service – Defended Area Information
The following attributes will be returned for Defended Area: (SoP, Level):

Attribute Data Type Description 
Level Integer Indicates if the Standard of Protection (SoP) and polygon areas are based on sourced data and/or assumptions.
SoP Integer Standard of Protection assigned to individual polygon areas representing a Defended Area.
This is expressed as a return period of 1 in 20 years or more.
A value of 50 indicates a Standard of Protection up to a river flood hazard return period of 1 in 50 years.

The following table explains the levels assigned to the Defended Area polygon according to the number of assumptions included:

Level Source of SoP Source of Area Polygon
0 No Data No Data
1 Assumed Assumed
2 Assumed Sourced
Sourced Assumed
3 Sourced Sourced

Accessing the Service

To access the Location Hub Flood service you must first be authorized for use with Location Hub Web Services in order to have a valid user name and password. Please contact info@dmtispatial.com for more information on how to register for the Location Hub Flood Web Service.
Once you have a valid user name and password, please refer to the Authentication section for information on how to access the service.