Flood risk assessments for planning in Bristol, tidal Avon, tide-locking, Temple Quarter, Western Harbour, St Philips Marsh and surface water flooding.
Bristol City Council published a Level 2 SFRA in 2023, covering the major regeneration areas at Western Harbour, Bristol Temple Quarter and St Philips Marsh in detail. Applications for these sites that do not engage with the Level 2 model data are likely to receive an EA objection, the standard Level 1 data is not sufficient for these locations. The Avon Riversides 2100 strategy received Outline Business Case approval in January 2024, but its defences have not been constructed and cannot yet be relied upon in planning FRAs. Development proposals cannot assume the strategy will be delivered.
Bristol’s tide-locking mechanism is a specific technical feature that does not apply in the same way across most of England. It is one of the most commonly misunderstood aspects of Bristol flood risk, and getting it wrong in a drainage strategy will draw an EA or Bristol City Council objection.
“A Flood Risk Assessment should be an engineering exercise, not a template report. At FPS Environmental every assessment is bespoke, focused on assessing flood risk thoroughly and supporting viable development.”
Simon Crowther BEng (Hons) FCIWEM C.WEM MIET
Director, FPS Environmental
Bristol’s five flood sources interact across the city: tidal flooding from the tidal River Avon and Avon Gorge, fluvial flooding from the Avon and its tributaries, surface water flooding across the urban area, sewer flooding from Wessex Water’s drainage network, and tide-locked watercourse flooding where tributary outfalls are prevented from discharging during high tide. Understanding which sources apply to a specific site, and how they interact, is the starting point for any Bristol FRA.
Tide-locking is the most distinctive and frequently misunderstood feature of Bristol flood risk. Lower sections of the Frome, the Trym, the Malago, the Brislington Brook and other tributaries flow into the tidal Avon. At high tide, the tidal water level in the Avon is often higher than the water level in the tributary, preventing drainage from discharging. During these periods, surface water drainage outfalls from development sites that connect to these watercourses effectively cannot function. A drainage strategy that does not model outfall performance under tide-locked conditions, assessing surface water storage requirements when the receiving watercourse is at high tide level, is incomplete. This is a specific Bristol requirement and a common cause of FRA or drainage strategy objections.
Bristol’s Surface Water Management Plan identifies 13 specific hotspot areas across the city where surface water flooding risk is documented. The areas include Barton Hill, Hartcliffe, Hengrove, Knowle West, Lawrence Weston, Lockleaze and others. Development in or near these hotspot areas must demonstrate effective on-site surface water management. Wessex Water’s drainage capacity constraints are material for development across the city.
• Development in Flood Zone 2 or 3, covering much of central, eastern and riverside Bristol
• Major development at Western Harbour, Temple Quarter or St Philips Marsh requiring Level 2 SFRA engagement
• Development near tide-locked tributaries where drainage strategy must account for outfall restriction at high tide
• Development in one of Bristol’s 13 SWMP surface water hotspot areas
• Development of 1 hectare or more in Flood Zone 1
• Development requiring a surface water drainage strategy under Bristol City Council and Wessex Water requirements
We understand Bristol’s specific FRA requirements, tide-locking mechanics, the Level 2 SFRA 2023 for the major regeneration sites, the Avon Riversides 2100 strategy limitations and the SWMP surface water hotspot areas. We do not apply a generic river flooding assessment to a Bristol application.
Our FRAs engage with EA tidal and fluvial model data directly. We address tide-locked outfall performance in drainage strategies as a standard requirement for Bristol sites near affected watercourses, not as an afterthought.
We cover Bristol City, South Gloucestershire, North Somerset and Bath and North East Somerset.
Years combined civil & environmental engineering experience
Years delivering drainage, design and risk advisory
Projects including individual assets valued at £1 billion+
Drainage design and flood risk commissions delivered
Here are some of our latest testimonials from satisfied clients. If you’d like to discuss your requirements further, please don’t hesitate to get in touch.
We are a charity owning a large parcel of land where gathering water is then affecting neighbouring properties. Received expert flood risk and drainage advice from FPS Environmental Ltd. All dealings with them were timely and professional. Site visit arranged where we were able to fully discuss causes and solutions. Great peace of mind obtained from engaging their expertise.
Michael Rowell
Landowner
The report I received was for a Flood Survey which was very thorough and clearly a lot of work had gone into it. The team were always available and conscious of deadlines. I would definitely recommend them if you are looking to get a flood survey completed.
Mike Gray
We spent thousands of pounds on poor quality investigations before reaching out to FPS Environmental. Most surveyors over promised and underdelivered creating tremendous stress for me and my family. FPSE has been absolutely amazing from the very beginning. They treated us with respect and restored our faith in this industry. We are incredibly grateful to them and highly recommend the company to anybody who wants to get a top product and piece of mind.
George Albota
I have used FPS, Simon and his team on several occasions over the last few years to advise on the flood risk and mitigating factors on both houses and prospective businesses. They have deep expertise and contacts across the spectrum of flood management. In particular, I have found their assessment reports invaluable. Whilst they are understandably busy, they are good to deal with and I would have no hesitation recommending them to anyone who is looking for advice in the sector.
Richard Warburton
Business Owner
FPS was really helpful in providing consulting advice in connection with a residential property acquisition. Sebastian from FPS undertook the survey and followed up with a full report and a consultation call to run through everything. The basic desktop data suggested a high flood risk, but this property-specific survey allowed us to take a well-informed position following Sebastian’s advice. Great work – and he and the FPS team were really helpful throughout the process. I’d certainly recommend them.
Richard Brandon
Very impressed with FPS Environmental Ltd and the guidance we have received to date. We had an hour long online consultation with the principal surveyor, and it was extremely helpful and productive. Thank you FPS. Will use the company again and highly recommend.
Helen Sutherland
FPS were able to work to our schedule and fit in an appointment at short notice. There was great communication from the office staff keeping us informed of any changes or requirements before the site visit.
The site survey was very thorough and Simon very knowledgeable, and quite happy to answer all questions. The provided report was extensive with usable information and recommendations. I will use FPS in the future and happily recommend them to all of my clients.
Drew Kirkland-Crawford
Deadwood Services Ltd
Send us your project brief and we will come back with a scope and indicative fee. Where additional input is required, this is provided on a formal instruction basis.
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