Southwest Environmental Limited

London Flood Risk Assessments (FRA)

Are you planning a development in London or across the Greater London boroughs? At Southwest Environmental Limited, our London office provides highly technical Flood Risk Assessments (FRA). We help you navigate stringent Environment Agency regulations, local borough planning policies, the London Plan, and complex hydrological constraints unique to the Thames catchment.

Hyper-Local London Flood Data & Modelling

London's flood risk is often characterised by the complex interaction between the Thames Estuary tides, tidal defenses (such as the Thames Barrier), inland river tributaries (such as the Lea, Wandle, and Brent), and surface water run-off in highly paved urban environments. Local borough planning authorities demand highly specific data alignment with local Strategic Flood Risk Assessments (SFRA). We utilize site-specific data including:

• Climate Change Adjustments: We incorporate peak rainfall and climate change allowances in line with Environment Agency guidance to future-proof urban developments against heavy rainfall and tidal rise.
• Tidal and Fluvial Interactions: Assessing residual flood risk behind Thames tidal defences, breach modelling, and discharge considerations across central and outer London boroughs.
• Sequential & Exception Tests: Providing robust evidence required by local planning authorities to pass vital planning tests, especially for complex urban brownfield redevelopments located within Flood Zones 2 and 3.

Flood Warning and Evacuation Plans (FWEP)

While an FRA identifies the level of risk, local planning officers frequently require a Flood Warning and Evacuation Plan (FWEP) to outline practical procedures for occupant safety. In tidal risk areas along the River Thames or near major tributaries, we establish safe refuge strategies and dry escape routes to satisfy local emergency planners.

Why Choose Our London Team?

Operating from our London office, we combine local GIS datasets with site-specific analysis to interpret complex flood data for Greater London planning applications. Whether your project requires a Surface Water Management Strategy (SuDS) for a high-density urban infill scheme or a full FRA for a commercial development, our accredited consultants transform raw flood data into actionable planning intelligence.

Contact our London Office today on 02076 920 670 or email london@southwest-environmental.co.uk to discuss your Flood Risk Assessment requirements.

Example Projects & Case Studies

Our environmental consultants frequently address varied flooding challenges across the country. Here are some examples of our work and technical insights from our weblog:

• Flood Depth & Flow Data Analysis: An overview of how we utilize climate change adjusted flood depths and site-specific hydraulic modeling for urban planning submissions.
• Flood Risk Assessment Data (Blog): Discussing the importance of collecting a wide selection of third-party data to accurately characterize flood risk on urban brownfield sites.
• 60 Day Rule for Leisure & Flood Risk: Guidance on submitting site-specific flood risk assessments and mitigation measures for leisure and temporary land uses.
• Recent FRA Projects & Climate Change Allowances: Case studies detailing how we establish finished floor levels (FFL) with vertical offsets to ensure long-term development resilience.

What Our London Clients Say