Our Flood Risk and Drainage Assessment Projects

These flood risk and drainage project case studies show how Unda gets real schemes through planning and past the obstacles that hold them up. The work spans large residential and commercial developments, single dwellings, extensions and change-of-use applications, and it reaches back to 2014 — more than 5,000 assessments across England and Wales, each one signed off by a chartered, CIWEM-qualified consultant.

The examples are deliberately mixed, because the problems behind them are. Some are planning submissions that needed a robust flood risk assessment for a site in Flood Zone 2 or 3, or a Flood Consequence Assessment for land in Wales. Several turned on a Sequential Test, and several more began with an Environment Agency objection that was withdrawn once the evidence was laid out properly. A number are not planning cases at all — homebuyers and property owners who needed the real flood risk to a specific building clarified before they signed.

What decides most of these cases is rarely the flood risk on its own — it is how clearly that risk, and the way it has been managed, is set out in the evidence.

What these projects show

• Difficult sites, approved. Schemes in Flood Zone 2 and 3 carried through with a proportionate assessment rather than an over-scoped one, and taken to appeal where the case demanded it.
• Drainage that satisfies the LLFA. Surface water drainage strategies and SuDS design that control run-off to policy and discharge the drainage conditions attached to a permission.
• The flood source the maps miss. Groundwater assessments and bespoke flood modelling for sites where the national mapping was too blunt to rely on.
• Purchase and insurance decisions clarified. The real risk to a particular building, judged against its own levels and history rather than a postcode-level label.
• Local knowledge, applied. Every case is grounded in the area, river and local authority that governs the site — and you can start your own check with our free flood risk map and live river levels map.

The case studies below each set out the site, the obstacle and how it was resolved. If your project faces something similar, you can see the full range of our flood risk assessment services or go straight to a quote.