Adding your flood assets (Grant Memorandum - Annex IV)

Flood schemes 

Lead Local Flood Authorities need to send us a set of data when they:

  • build a new flood scheme
  • change, maintain or update an existing flood scheme, asset, or group of assets

We need this data to update: 

This will help give the public a transparent, accessible, and consistent view of flood assets, investment and risk reduction across Wales.

The data we need forms Annex IV of the Grant Memorandum and Measure 7 of National Strategy for Flood and Coastal Erosion Risk Management in Wales.

Updating our maps

If you have created or updated flood defences, we will draw a new location or update the asset location on our map for: 

  • flood defences
  • culvert openings
  • screens
  • any other asset types in the future 

We will also work with you to:

  • create a new polygon in the FRAW map to show the areas that benefit from the flood defences with a standard of protection
  • draw a new TAN15 defended zone with a standard of protection in the FMfP. The new standard of protection will need to meet the FMfP thresholds

The benefits of adding your assets

Adding your new or updated flood assets to our maps may mean that your communities benefit from: 

  • a better representation of their flood risk
  • a better understanding of their standard of protection 
  • increased awareness and better understanding of how flood risk is managed 
  • up-to-date representation of their community in the Community at Risk Register

Submitting your flood asset data

Contact to discuss submitting your flood asset data. We will send you a proforma spreadsheet which includes the fields below. You will also need to include supporting files.  

* are mandatory fields. Complete all fields, where you have data available. 

Local authority*

Waterbody type*

Asset type*

Asset unique reference*

Asset sub type*

Asset name*

Asset condition*

Last inspection date*

Asset maintainer*

Asset owner*

Primary purpose* (Flood risk management only, erosion protection in the future)

Protection type*

Asset description*

Location description*

Replacement costs*

Standard of Protection*

Assessed residual life* if calculated

Grid reference*

Build date*


Upstream crest level

Downstream crest level

Height (m) (if available)

Length* (m)

Depth (m)

Diameter* (m) (mandatory for culverts only)

GIS object ID

Photograph filename

Photograph file path



By submitting your asset data, you agree that we can use it under open government licence. It's your responsibility to check the quality of the data before you submit it. We do not check the data before we publish it. 

Submitting your flood modelling

Submit any hydraulic models you've created for your new or updated flood scheme as a Flood Map Challenge. We will update FRAW and FMfP to give a more up-to-date picture of flood risk. 

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