Step-by-Step Tutorial
What is DEFRA Survey Data?
DEFRA Survey Data is the UK Environment Agency’s official portal for accessing elevation data collected for flood risk management. It provides free access to LiDAR point clouds, digital terrain models, and digital surface models covering approximately 99% of England.
Environment Agency Survey Information Hub showing LiDAR terrain visualization
01
Navigate to DEFRA Survey Data
Go to environment.data.gov.uk/survey to access the Environment Agency’s survey data portal.
The interface features:
- Interactive Map – Browse data coverage visually
- Search – Find locations by place name or postcode
- Filter Options – Filter by data type and resolution
- Product Selection – Choose between point cloud, DTM, or DSM
02
Search for Your Location
Use the Search function to find your area of interest.
You can search by:
- Place name – City, town, or village (e.g., “London”, “Manchester”)
- Postcode – UK postcode (e.g., “SW1A 1AA”)
- Coordinates – British National Grid or lat/long
Zoom in on the map to see available data tiles for your area. Coloured tiles indicate data availability at different resolutions.
Open Data Products page showing available LiDAR datasets and download options
Layers panel showing LIDAR Composite options including DTM and DSM layers
03
Select Product Type
Choose your desired data product from the available options:
Product Types:
- LIDAR Point Cloud – Raw point cloud data in LAZ format
- LIDAR Composite DTM – Digital Terrain Model (ground only)
- LIDAR Composite DSM – Digital Surface Model (including objects)
Available Resolutions:
- 1m – Higher resolution data for detailed analysis
- 2m – Standard resolution with broader coverage
Note: 25cm and 50cm resolution data has been withdrawn from the portal.
04
Select Data Tiles
Click on the map to select individual tiles or use area selection tools:
Selection Methods:
- Click tiles – Select individual 1km x 1km tiles
- Draw area – Draw a polygon to select multiple tiles
- Shift+click – Add or remove tiles from selection
The download list will show all selected tiles with file sizes. Data is organized using the British National Grid reference system.
Operational layers panel showing available data categories
Download panel with polygon drawing tools for area selection
05
Download Your Data
Once tiles are selected, proceed with the download:
- Review selection – Check the download list for selected tiles
- Click Download – Files are served directly from the portal
- No registration required – Data is freely available without an account
File Formats:
- Point clouds: LAZ (compressed LAS)
- DTM/DSM: ASCII Grid (.asc) or GeoTIFF (.tif)
Larger areas may require multiple downloads. Each tile covers 1km x 1km.
Available File Formats
DEFRA Survey Data offers multiple data formats optimized for different use cases:
| Format | Type | Best For |
|---|---|---|
| LAZ | Point Cloud | Compressed LiDAR – ideal for storage and processing in GIS software |
| ASCII Grid | Raster | DTM/DSM elevation grids – compatible with most GIS applications |
| GeoTIFF | Raster | DTM/DSM elevation grids – standard format for terrain analysis |
| OSGB36 | Coordinate System | British National Grid (EPSG:27700) – standard UK mapping projection |
Tips for Downloading UK Environment Agency LiDAR
🎯 Check Resolution Availability
1m and 2m resolution data is widely available. Note that 25cm and 50cm resolution data has been withdrawn from the portal.
📦 Use LAZ Format
LAZ files are 5-10x smaller than LAS with no data loss. Most modern software supports LAZ directly, including QGIS and CloudCompare.
🗺️ Understand the Grid System
Data uses British National Grid references (e.g., TQ3080). Each tile covers 1km x 1km. Familiarize yourself with OS Grid references for efficient navigation.
🔍 Check Survey Dates
Data is collected over time for flood risk management. Check metadata for survey dates to ensure data currency for your application.
Process Your UK LiDAR in Lidarvisor
Downloaded your Environment Agency files? Process them instantly in the cloud with Lidarvisor.
With Lidarvisor, you can:
✦ Upload LAZ/LAS files directly to the cloud
✦ Automatically classify ground, vegetation, buildings, and water
✦ Generate DTMs, DSMs, and contour lines
✦ Export to CAD-ready formats (DXF, SHP)
✦ Process large datasets without hardware limitations
Frequently Asked Questions
Yes! All data from the Environment Agency is available free of charge under the Open Government Licence (OGL). You can use the data for personal, commercial, and research purposes. Attribution to the Environment Agency is required.
No account is required for downloading data. You can access and download LiDAR point clouds, DTMs, and DSMs directly from the portal without registration.
The Environment Agency currently provides:
- 1m resolution – Most detailed available data
- 2m resolution – Broader coverage with slightly less detail
Note: 25cm and 50cm resolution data has been withdrawn from the portal. For most applications, 1m resolution provides excellent detail for terrain analysis, flood modelling, and planning purposes.
Environment Agency LiDAR data has a vertical accuracy of approximately ±15cm RMSE (Root Mean Square Error). This makes it suitable for:
- Flood risk assessment and modelling
- Terrain analysis and volumetric calculations
- Urban planning and development
- Archaeological surveys
Horizontal accuracy is typically ±40cm.
All Environment Agency data uses the British National Grid coordinate system:
- OSGB36 / British National Grid (EPSG:27700)
- Heights are in metres above Ordnance Datum Newlyn (ODN)
If you need data in a different coordinate system, you can reproject using GIS software like QGIS or with Lidarvisor’s processing tools.
Approximately 99% of England is covered by Environment Agency LiDAR data. Coverage has been built up over many years primarily for flood risk management purposes. Some remote or less flood-prone areas may have limited coverage. Use the map interface to check availability for your specific area of interest.