SuDS Drainage Strategies & Sustainable Drainage Design
Surface water drainage strategies, detailed SuDS design and LLFA proforma completion for planning applications across England and Wales.
SuDS Drainage Strategies Written to Pass First Time
Flood Risk Environmental is an independent SuDS and drainage consultancy with over 17 years' experience preparing surface water drainage strategies, sustainable drainage designs and detailed SuDS packages for planning applications across England and Wales.
We work directly with developers, architects and planning consultants to produce technically robust, LLFA-compliant drainage reports — written to satisfy the Environment Agency, Lead Local Flood Authority and Local Planning Authority requirements at first submission.
Whether you need a simple outline drainage strategy for a minor application or a full detailed SuDS design package with hydraulic modelling and condition discharge documentation, we provide a complete, end-to-end drainage service.
Get a Free QuoteWhen Do You Need a SuDS Drainage Strategy?
Most planning applications in England and Wales that involve new or altered impermeable surfaces require a surface water drainage strategy demonstrating SuDS compliance. Common triggers include:
New Residential Development
Any new dwellings or extensions creating additional impermeable area require a SuDS drainage strategy to satisfy LPA and LLFA planning conditions.
Commercial & Industrial Sites
Large roof areas, car parks and hardstanding require SuDS drainage design to restrict runoff rates and protect receiving watercourses from flood risk.
LLFA Pre-App or Drainage Condition
Where a Lead Local Flood Authority has raised surface water drainage as a pre-application concern or imposed a pre-commencement drainage condition.
Major Applications (10+ dwellings)
Major planning applications require a full SuDS drainage strategy demonstrating compliance with the NPPF, CIRIA C753 and local SuDS design standards.
Change of Use
Converting land or buildings that significantly increases impermeable coverage typically requires drainage assessment and surface water mitigation.
Discharge of Drainage Conditions
Pre-commencement or pre-occupation drainage conditions requiring detailed SuDS design, calculations and drawings to be approved before works commence.
SuDS Drainage Strategy & Design Services
From outline surface water drainage strategies for planning submission through to full detailed SuDS design packages for condition discharge — we deliver the complete drainage scope.
Surface Water Drainage Strategy
Outline and detailed SuDS drainage strategies for planning applications, demonstrating compliance with NPPF, CIRIA C753 and local SuDS standards. Covers greenfield and brownfield sites across all LLFA areas.
- Greenfield and brownfield runoff rates (FEH22/IH124)
- SuDS hierarchy and infiltration assessment (BRE 365)
- Surface water attenuation sizing and outfall design
- LLFA and LPA-ready drainage strategy reports
- Sequential and Exception Test drainage input
Detailed SuDS Design
Full detailed sustainable drainage design for planning condition discharge, including hydraulic calculations, drainage layout drawings and construction specifications for all SuDS features.
- Attenuation storage sizing (Flow+ v16 / MicroDrainage)
- Design of rain gardens, swales, permeable paving & filter drains
- Geocellular storage and attenuation tank design
- AutoCAD drainage layout and long-section drawings
- SuDS construction details and specifications
Drainage Condition Discharge
Complete drainage condition discharge packages to satisfy pre-commencement or pre-occupation planning conditions and secure written LLFA approval.
- Technical response to LLFA drainage objections
- Revised SuDS calculations, drawings and specifications
- SuDS Maintenance & Management Plans (MMP)
- Adoption and Section 106 drainage obligations
- Liaison with LLFAs and highway drainage authorities
LLFA SuDS Proforma Completion
Many Lead Local Flood Authorities across England and Wales require applicants to submit a standardised SuDS proforma alongside their planning application. These technical documents must demonstrate compliance with local SuDS drainage standards — and incorrectly completed proformas are one of the most common causes of LLFA drainage objections and planning delays.
We complete LLFA SuDS proformas on your behalf, either as part of a full surface water drainage strategy or as a standalone service. Our proforma submissions are prepared to LLFA specification and cross-referenced to supporting drainage calculations.
- All LLFA SuDS proforma formats covered across England and Wales
- Greenfield runoff rates and attenuation volumes calculated to LLFA spec
- SuDS hierarchy assessment and infiltration testing interpretation
- Attenuation sizing, restricted outfall design and exceedance routing
- Water quality treatment train and SuDS feature selection
- Long-term maintenance and adoption responsibilities addressed
How It Works
From your initial enquiry to a planning-ready SuDS drainage strategy in as little as five working days.
Free Quote
Send us your site address and planning reference. We confirm the drainage scope and provide a fixed fee within 24 hours.
Site & Data Review
We review site plans, topographic data, EA and LLFA requirements. We confirm whether a site visit or infiltration testing is needed.
Drainage Design & Report
We prepare your SuDS drainage strategy, hydraulic calculations and AutoCAD drawings — formatted for direct planning submission.
Revisions & LLFA Support
One round of revisions included as standard. We respond to LLFA technical drainage queries and objections where scope permits.
Trusted by Developers, Architects & Planning Consultants
We work with clients ranging from individual homeowners to national developers, delivering drainage strategies that pass first time.
“Antony was great to work with when we needed a Flood Risk Assessment and Emergency Flood Plan. As an architect I would definitely use FRE Consultants again — professional and produced reports within a good time frame.”
“The service received was great and at a competitive cost. We were granted planning after first submission.”
“Fast, technically thorough and understood exactly what the LLFA needed. The drainage strategy was approved without any queries. Would highly recommend for any drainage or flood risk work.”
Frequently Asked Questions
Need a SuDS Drainage Strategy or Detailed Design?
Free, no-obligation fixed-fee quote within 24 hours. All LLFAs and drainage conditions covered across England and Wales.
Get a Free QuoteOr contact us directly: 07826 705389 •