Flood Depth Grids for England, 2004 Generalised Model

Environment Agency modelled fluvial flood depth data was created for the 1% annual chance of flooding situations as a by-product from the 2004 generalised modelling project. The data was produced using the JFlow two-dimensional hydrodynamic model on a 5x5m grid to fill gaps where no detailed local modelled data existed. This dataset covers the Ordnance Survey National Grid reference ST, with similar data available for the whole of England.

Use Cases

• Assessing broad catchment-scale flood risk based on modelled flood depth grids.
• Supporting spatial planning at a Shoreline Management Plan scale based on generalised flood extents.
• Providing a historical baseline for flood zone definition where detailed local models are unavailable.

Strengths

• Data was produced using a two-dimensional hydrodynamic model (JFlow) on a 5x5m grid.
• Created to define extents of Flood Zones for spatial planning across England.
• Modelled for a specific flood probability scenario (1% annual chance).

Limitations

• The dataset has not been updated since its creation in 2004.
• Description metadata is limited; actual data quality requires manual inspection after download.
• The data is explicitly not suitable for identifying whether an individual property will flood or for detailed decision making.

Provenance

Source

Environment Agency, with digital spatial data licensed from Centre for Ecology & Hydrology (CEH) and other organizations.

Collection Method

Modelled using the JFlow two-dimensional hydrodynamic model.

Time Range

Model created in 2004.

Geography

Coverage for Ordnance Survey National Grid reference ST, with data available for the whole of England.