Adding your flood assets (Grant Memorandum - Annex IV)

Local authority flood schemes 

Local authorities (Flood Risk Management Authorities) need to send us a set of data when they:

  • build a new flood scheme
  • change or update an existing scheme

We need this data to update the National Flood Asset Database and accompanying map. This will help give the public a transparent, accessible, and consistent view of flood assets and investment across Wales.

The data they need to send us is laid out in the Grant Memorandum - Annex IV and Measure 7 of National Strategy for Flood and Coastal Erosion Risk Management in Wales

How will we use your flood asset data?

We will use data about your flood schemes to update our map layers for: 

  • flood defences
  • culvert openings
  • screens

Where there are new or updated flood defences, we will: 

  • draw a new defence line on our map
  • create a new polygon to show the areas that benefit from the flood defences
  • draw a new TAN15 defended zone if the the new standard of protection is high enough

Any changes to our mapping would have to be supported by detailed hydraulic modelling.

The benefits of adding your flood assets to our maps

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

  • having a lower flood risk
  • lower flood insurance costs
  • fewer problems getting mortgages 
  • better safety and well-being

We might also be able to assess some types of developments if your flood assets are accurately recorded in the National Asset Database and in our maps. 

Submitting your flood asset data

This page is under development. Contact us to discuss what you need to include in your flood asset data 

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