LLFA SuDS Pro Forma • Drainage Strategy • Defra Standards

SuDS Pro Forma Completion with Supporting Drainage Strategy

Many LLFAs require their SuDS pro forma completed and submitted with a surface water drainage strategy to validate an application or discharge a condition. We complete the pro forma and provide the calculations behind it.

Any LLFA pro forma
Greenfield runoff rates
UKSuDS & Causeway calcs
Defra SuDS standards
Condition discharge

LLFA SuDS Pro Forma & Drainage Strategy

A growing number of Lead Local Flood Authorities now require their own surface water drainage pro forma (sometimes called a SuDS checklist or drainage assessment form) to be completed and submitted alongside a drainage strategy — either to validate a major application or to discharge a surface water drainage condition. A blank or unsupported pro forma is routinely rejected, holding up determination.

We complete the specific pro forma for your LLFA and provide the technical drainage strategy that evidences every answer on it — runoff rates, storage volumes, the drainage hierarchy and the SuDS components — so the submission stands up to LLFA scrutiny first time. The work is prepared to the non-statutory technical standards for SuDS (Defra, 2015), CIRIA C753 and your LLFA’s local standards.

What’s Included

  • LLFA pro forma completed in full — whichever form your authority uses, completed and cross-referenced to the strategy
  • Greenfield runoff rates — QBAR and the 1, 30 and 100-year rates derived using IH124 / FEH methods via UKSuDS
  • Attenuation storage design — volumes calculated for events up to the 1 in 100-year plus climate change allowance
  • Drainage hierarchy justified — infiltration, watercourse, then sewer, with discharge rates restricted to greenfield where required
  • SuDS component design — permeable paving, geocellular crates, basins, swales or proprietary devices appropriate to your site
  • Maintenance & management — SuDS management plan and adoption position where the LLFA requires it
Rain garden and sustainable drainage Surface water drainage pipework Watercourse for surface water discharge

When Do You Need a SuDS Pro Forma?

Send us your LLFA and planning reference and we’ll confirm exactly what they need. Get a free quote.

Major Applications

Most LLFAs require a completed surface water pro forma and drainage strategy as a validation requirement for major development (10+ dwellings or 0.5ha+).

Discharging a Drainage Condition

Where a surface water drainage condition has been imposed, the LLFA pro forma plus a detailed strategy is the standard route to discharge it.

Responding to an LLFA Objection

If the LLFA has objected on drainage grounds, a properly completed pro forma backed by calculations is the quickest way to resolve it. See our objection response service.

Householder & Minor Schemes

Some authorities now ask for a simplified drainage pro forma even on minor and householder applications, particularly in surface-water flood risk areas.

Brownfield Redevelopment

Redevelopment must usually demonstrate a betterment in runoff rate; the pro forma captures the existing versus proposed position, which we evidence with calculations.

Full SuDS Strategy

Where a complete strategy is required rather than just a pro forma, see our SuDS drainage strategy service.

Frequently Asked Questions

What actually is a SuDS pro forma?
It’s a standard form issued by your LLFA that captures the key surface water drainage parameters for your site — runoff rates, discharge destination, storage provision, SuDS components and maintenance. It is the LLFA’s checklist for confirming a scheme complies with national and local standards.
Do all LLFAs use the same form?
No — each authority has its own version, and the level of supporting detail expected varies. We work to whichever pro forma your LLFA uses and tailor the strategy to their local standards.
Is the pro forma enough on its own?
Almost never. The pro forma summarises the position, but the LLFA expects the calculations, drainage layout and SuDS design behind it. We provide both so the submission is complete.
Can you discharge the drainage condition for me?
Yes — completing the pro forma and strategy to discharge a surface water condition is one of the most common reasons clients come to us. We prepare the submission and respond to any LLFA queries.
How quickly can you turn it around?
A pro forma with supporting drainage strategy is typically delivered within 5–10 working days, depending on whether infiltration testing is required. We’ll confirm a timescale with your fixed-fee quote.

Get a Free Quote

Free, no-obligation fixed-fee quote within 24 hours. All flood zones and LLFAs covered across England and Wales.

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Flood Risk Environmental

Flood Risk & Environmental Consulting • Independent Flood Risk, Drainage & Utilities Consultants

07826 705389  • 

Leicestershire, England • Covering all of England & Wales

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