Southwest Environmental Limited

Flood Depth & Flow Data Map Bristol

The below map shows flood flow and depth data used in a Flood Risk Assessment in Bristol.

This data is taken from the Bristol Strategic Flood Risk Assessment Modelling Report.

Flood Risk Depth Map Bristol

This map contains lots of data. For a Flood Risk Assessment we typically use a 1:100 flood depth. This means a flood event that occurs only once every 100 or 200 years, so a really bad flood. In more recent years we are also required to add a climate change adjustment for the flood, typically allowing for 40% greater flow in rivers, and therefore deeper water.

BRISTOLSFRA_2120_0100_T0001_F0100CC70_Stage_T0001_F0100CC70Yrs

Look for the above descriptor when choosing the flood depth. We have guessed what it means but fairly sure, this is 2120 Flood Outline Level for Climate Change Adjusted 1:100 Year Event. And this is the Flood Level we would use for a design flood level.

Please use below map as you see fit, if you would like a Flood Risk Assessment for your project please contact us.

The below section was written by a machine.

Hyper-Local Technical Resources: Bristol Flood Risk Data

Effective planning in Bristol requires a granular understanding of the city's complex hydrological profile. As a tidal city with significant fluvial influences from the River Avon and its tributaries, generic national data often lacks the precision required for high-stakes Flood Risk Assessments (FRA). This dataset provides technical insight into local flood mechanisms, helping developers navigate the specific requirements of Bristol City Council's planning policies.

Bristol Hydrological Constraints

Bristol's flood risk is characterized by the interaction between the Severn Estuary tides and inland river systems. Understanding these hyper-local variables is essential for accurate flood zone modelling. Key data points for the Bristol area include:

• River Avon Tidal Influence: Analysis of how tidal surges impact discharge rates in the city center and downstream areas like Avonmouth.
• Strategic Flood Risk Assessment (SFRA) Alignment: Ensuring site-specific data aligns with the latest Bristol City Council SFRA findings and climate change allowances.
• Surface Water Hotspots: Identifying areas of the city prone to pluvial flooding where a robust SuDS Strategy is mandatory.
• Local Infrastructure Impact: Data regarding the floating harbour levels and the operation of the Cumberland Basin locks during high-flow events.

Data for Planning and Development

For projects within the Bristol area, referencing hyper-local data is critical for passing the Sequential Test. Our datasets support developers in creating resilient designs that account for the unique topography of the Somerset Levels and the Avon Gorge. By integrating this evidence into Environmental Impact Assessments (EIA) and residential planning statements, we ensure that project risks are mitigated early in the design cycle.

Technical Authority and Local Expertise

With a track record of delivering over 900 projects across the UK, Southwest Environmental Limited provides the technical authority required to interpret complex data for the Bristol planning landscape. We combine local GIS datasets with site-specific soakaway testing (BRE 365) to provide a holistic view of water management. Our consultants, accredited by the IES and CIWEM, transform raw flood data into actionable planning intelligence.