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85 posts found
Perched Groundwater: How to Tell It From the Water Table
Perched groundwater is a body of shallow groundwater held above the main water table by a layer of low-permeability ground, with unsaturated material beneath it. That unsaturated gap is the definition. Water standing in a trial pit on a clay…
Posted on 21st September, 2026
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Drainage
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Geology
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Technical Insights
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Understanding Flood Risk
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Kasumi-tei: how Japan built levees with gaps in them on purpose, and why it stopped
An open levee is a flood embankment built in overlapping segments with deliberate gaps left between them, so floodwater can spread sideways onto farmland as the river rises and drain back out through the same gaps as it falls. Japan…
Posted on 18th September, 2026
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Drainage
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Flood Defence
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Flood History
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Natural Flood Management
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News & Updates
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Understanding Flood Risk
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Groundwater Source Protection Zones: What They Are and What They Change
A groundwater source protection zone is an area the Environment Agency draws around a groundwater drinking water abstraction to show how quickly a pollutant released at that point would reach the supply. There are over 2,600 of them in England.…
Posted on 16th September, 2026
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Drainage
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Environment Agency
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Flood Risk Assessment
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Land drains on a development site: what to do when you find them
Land drains on a development site are not an obstruction to be cleared. They are somebody's drainage, they may carry water from well beyond the red line, and cutting one without a plan is the shortest route to a neighbour's…
Posted on 15th September, 2026
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Drainage
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Natural Flood Management
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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The oldest drainage system in the world: who actually has the claim
A stone drainage system roughly 5,000 years old was reported at Liman Tepe on the Turkish Aegean coast on 14 September 2026, and the coverage reached, as it usually does, for the superlative. It should not have. There is no…
Posted on 14th September, 2026
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Drainage
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Flood History
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Flood Risk Assessment
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Natural Flood Management
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News & Updates
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Understanding Flood Risk
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129 drains and half a metre of loam: how Machu Picchu handles two metres of rain a year
Machu Picchu takes close to two metres of rain a year on a granite ridge that falls away at roughly 50% either side, and it has stood there for around six centuries. The photograph everybody knows is the part above…
Posted on 11th September, 2026
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Drainage
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Flood History
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Flood Risk Assessment
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News & Updates
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Understanding Flood Risk
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Whatever happened to Sewers for Adoption?
Sewers for Adoption was the design guide that told developers how to build a sewer a water company would take over. It stopped doing that job in England on 1 April 2020, when Ofwat's Code for Adoption Agreements came into…
Posted on 10th September, 2026
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Drainage
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Planning
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Sewer
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SuDS
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Policy & Legislation
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Technical Insights
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Medieval drainage: the moats, monks and great drains you can still go and see
Medieval drainage has a public-relations problem. The popular picture is a filthy street, a chamber pot tipped out of a window and a moat brimming with sewage. A thousand years of squalor, sitting neatly between the Romans and the Victorians.…
Posted on 8th September, 2026
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Drainage
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Flood Defence
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Flood History
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Flood Risk Assessment
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Natural Flood Management
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News & Updates
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Understanding Flood Risk
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Do You Need Planning Permission for a Swimming Pool?
Most people asking whether you need planning permission for a swimming pool get the same answer everywhere they look: probably not. That answer is usually right, and it is also the less useful half of the question. Permission settles whether…
Posted on 7th September, 2026
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NPPF
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Dry Weather Flow: What a Dry Day Spill Tells You About Sewer Capacity
Dry weather flow is the average daily volume reaching a wastewater treatment works when it has not been raining, and it is the number every foul drainage decision in a constrained catchment eventually rests on. When a storm overflow discharges…
Posted on 2nd September, 2026
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Drainage
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Planning
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Sewer
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Policy & Legislation
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Understanding Flood Risk
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BS EN 12056 explained: the standard for drainage inside buildings
BS EN 12056 is the British and European standard for gravity drainage inside buildings. It covers everything from the trap under a washbasin to the gutter on the roof, and it stops at the point where wastewater leaves the building.…
Posted on 1st September, 2026
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Drainage
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Planning
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Technical Insights
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Understanding Flood Risk
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Flood Risk and Drainage for Data Centre Planning Applications
A data centre flood risk assessment has to clear a higher bar than the industrial-shed template most schemes were still using a year ago. Since 17 August 2026 the National Planning Policy Framework has listed data centres as essential infrastructure.…
Posted on 28th August, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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Policy & Legislation
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Understanding Flood Risk
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Equestrian flood risk and drainage: the planning rules for stables, field shelters and ménages
Planning permission for stables is needed far more often than owners expect, and the flood risk and drainage requirements that come with it are the part almost nobody writes about. Horses are kept on low-lying grazing land: the cheap, wet,…
Posted on 27th August, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Flood Risk Assessments for Electrical Substations
A substation flood risk assessment establishes whether a proposed electrical substation will be reached by flooding during its working life, and sets the levels and the protection the equipment needs to survive it. It can be required for planning. It…
Posted on 27th August, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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Policy & Legislation
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Understanding Flood Risk
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Basement and Cellar Conversions in a Flood Zone: The 2026 Planning Rules
A basement conversion flood risk assessment has to answer a question no other householder application faces: what happens to the people in the lowest room when the water arrives. Below-ground space is the only part of a home where the…
Posted on 26th August, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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Policy & Legislation
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Understanding Flood Risk
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First flush explained: why the first few millimetres of rain matter most in SuDS
Every storm carries its dirtiest water at the start. In the first minutes of rain, run-off sluices weeks of built-up grime (oil, tyre and brake dust, sediment, metals and nutrients) off roofs, roads and car parks and into the nearest…
Posted on 21st August, 2026
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Drainage
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NPPF
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Flood Risk and Drainage for Gypsy and Traveller Sites: The Planning Requirements
A Gypsy and Traveller site flood risk assessment is needed for almost every pitch scheme on land that carries any flood risk, and these applications are judged against a tougher standard than ordinary housing. The reason is the caravan. Under…
Posted on 19th August, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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Policy & Legislation
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Understanding Flood Risk
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Section 104 and Section 102 Agreements: A Developer’s Guide to Sewer Adoption
A Section 104 agreement is the contract that gets a development's new sewers taken over and maintained by the water company; a Section 102 agreement does the same job for sewers that are already in the ground. Both sit in…
Posted on 18th August, 2026
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Drainage
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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What is a Section 106 sewer connection? The right to connect, explained
A section 106 sewer connection is the statutory right, under section 106 of the Water Industry Act 1991, for the owner or occupier of a property to connect its drains to the public sewer. It is a right, not a…
Posted on 18th August, 2026
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Drainage
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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NPPF August 2026 Changes: Flood Risk and Drainage Implications for Planning
The NPPF 2026 changes are now live. Government published the new National Planning Policy Framework on 17 August 2026, and it applies to planning decisions in England from the day of publication. For flood risk and drainage this is no…
Posted on 17th August, 2026
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Flood Risk Assessment
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Planning
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News & Updates
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Policy & Legislation
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Campsite and glamping flood risk and drainage: the planning requirements in England
A campsite flood risk assessment is required for any camping, glamping or holiday caravan proposal in Flood Zone 2 or 3, and for sites in Flood Zone 1 that are a hectare or more, sit in a critical drainage area,…
Posted on 17th August, 2026
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Environment Agency
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Flood Risk Assessment
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News & Updates
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Policy & Legislation
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Why do water mains burst in hot weather? The hidden burst season explained
Ask most people when a water main bursts and they picture winter: a hard frost, a deep freeze, the metal splitting as the water inside turns to ice. That is half the story. The other half is playing out right…
Posted on 13th August, 2026
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Drainage
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Planning
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News & Updates
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Understanding Flood Risk
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BS EN 752 explained: the standard for drains and sewers outside buildings
BS EN 752 is the British and European standard for drain and sewer systems outside buildings. It sets out what those systems have to achieve, and how they should be managed through planning, design, construction, operation and rehabilitation. The objectives…
Posted on 12th August, 2026
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Drainage
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Planning
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Technical Insights
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Understanding Flood Risk
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What have the Romans ever done for us? Aside from the drainage, obviously
Ask a Roman what they ever did for us and you would probably get a shrug and a wave at, well, everything. Put the same question to a flood-risk engineer, though, and the answer turns oddly specific: a startling amount…
Posted on 11th August, 2026
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Drainage
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Flood Defence
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History
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News & Updates
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Understanding Flood Risk
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Flood risk and drainage in the planning process: where they fit at every stage
If you are applying for planning permission for the first time, the part most likely to catch you out is not the design or the neighbours. It is flood risk and drainage in the planning process. Flooding and surface water…
Posted on 6th August, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Flood Risk Assessment and Drainage Strategy: Do You Need Both?
Most applications that need one of these documents need the other too. A flood risk assessment and a drainage strategy answer different questions: the first asks whether the site floods and whether your development makes flooding worse somewhere else, the…
Posted on 4th August, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Can a Planning Condition Make You Fix a Flood Problem You Didn’t Cause?
Almost every developer who has taken a drainage condition through to discharge has met some version of this. The site floods. The gardens next door flood. The culvert downstream has been surcharging since long before anyone applied for anything. And…
Posted on 29th July, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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PPG
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Policy & Legislation
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Understanding Flood Risk
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The British Geological Survey explained: what BGS data tells you about a site
The British Geological Survey is the UK's national geological survey and the public custodian of its geoscience records: a research centre of the Natural Environment Research Council, founded in 1835, holding the national geological map and more than a million…
Posted on 16th July, 2026
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Drainage
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Geology
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GIS
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Planning
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SuDS
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Technical Insights
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Understanding Flood Risk
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Building Regulations Part H: Foul Water Explained
Building Regulations Part H is the part of the building rules that governs foul water drainage: how the used water from a building's toilets, sinks, baths and appliances is carried away safely. If you are building, extending or converting anything…
Posted on 15th July, 2026
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Drainage
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Discharge of Planning Conditions: Process, Timescales and Costs (2026)
Discharge of planning conditions is the formal step of asking your local planning authority to confirm, in writing, that a condition attached to your planning permission has been satisfied. In planning terms it is an “application for approval of details…
Posted on 14th July, 2026
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Drainage
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NPPF
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Planning
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Policy & Legislation
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Understanding Flood Risk
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What Is a CON29DW Report? The Drainage and Water Search Explained
A CON29DW report is the official drainage and water search a conveyancer orders during a property purchase. Compiled from the water company's own records, it answers 26 standardised enquiries about how a property connects to the public water and sewer…
Posted on 10th July, 2026
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Drainage
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Policy & Legislation
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Understanding Flood Risk
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Why Does Rain Stop Play at Wimbledon? The Science of Grass Court Drainage
Every Wimbledon has the same ritual. A few spots of rain, the umpire calls a halt, and within seconds the ground staff are sprinting the covers across the grass. It looks like an overreaction on a warm July afternoon. It…
Posted on 8th July, 2026
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Drainage
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Flood Risk Assessment
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Planning
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SuDS
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Technical Insights
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Understanding Flood Risk
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How Football Pitch Drainage Works: Lessons from the 2026 World Cup
Watch a World Cup match in a downpour and the ball still runs true. There are no puddles on the halfway line, no spray kicking up at every pass. That is not luck. Football pitch drainage is a piece of…
Posted on 7th July, 2026
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Drainage
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Flood Risk Assessment
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SuDS
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Technical Insights
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Understanding Flood Risk
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Do building control and planning talk to each other? Drainage, SuDS and the gap between them
A building control officer tells you the simplest thing to do is run the surface water into the sewer. Your planning condition says infiltration first, greenfield runoff rates, attenuation for a one-in-100-year storm. Both cannot be right, and only one…
Posted on 3rd July, 2026
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Drainage
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Flood Risk Assessment
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Planning
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Policy & Legislation
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Understanding Flood Risk
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Retrospective Planning Permission: The 2026 Guide
Retrospective planning permission is planning permission applied for after building work has already started or finished. It is made under Section 73A of the Town and Country Planning Act 1990. It is then judged in exactly the same way as…
Posted on 2nd July, 2026
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Drainage
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Flood Risk Assessment
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Planning
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Policy & Legislation
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Understanding Flood Risk
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What Is a SuDS Proforma and When Is It Required?
A SuDS proforma — also called a drainage proforma or sustainable drainage proforma — is a standardised summary form that goes in with a sustainable drainage strategy on a planning application. It sets out the key drainage information in a…
Posted on 26th June, 2026
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Drainage
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Planning Application Invalidated? The Flood Risk and Drainage Documents You’re Missing
A planning application invalidated for flood risk or drainage almost always comes down to one thing: a document the local planning authority treats as mandatory is missing from the submission. Most often that is a flood risk assessment (FRA), a…
Posted on 22nd June, 2026
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Environment Agency
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Planning
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News & Updates
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Policy & Legislation
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The Four Pillars of SuDS Explained: Quantity, Quality, Amenity & Biodiversity
The four pillars of SuDS are water quantity, water quality, amenity and biodiversity — the four objectives a well-designed sustainable drainage system is meant to deliver at the same time. They come from the CIRIA SuDS Manual (C753) and now…
Posted on 16th June, 2026
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Drainage
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Planning
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SuDS
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Technical Insights
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Understanding Flood Risk
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Permeable Paving for Planning Applications: When It Works and When It Doesn’t
Permeable paving is one of the most common SuDS features used in drainage strategies for planning applications, and on the right site it is one of the most useful. It lets rainfall pass through the surface into a stone sub-base…
Posted on 15th June, 2026
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LLFA
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Planning
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SuDS
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Technical Insights
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Understanding Flood Risk
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Residual Flood Risk Explained: How It’s Assessed and Managed
Residual flood risk is the risk left over after defences, drainage and mitigation have done what they can. No scheme removes risk entirely. A defended site still floods if a barrier is overtopped, if a defence breaches, or if a…
Posted on 9th June, 2026
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Flood Defence
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Flood Risk Assessment
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NPPF
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Planning
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Technical Insights
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Understanding Flood Risk
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Surface Water Flooding and Planning: A Complete Guide for Developers
Surface water is the most widespread source of flood risk in England, and the August 2026 National Planning Policy Framework has made how you handle it decisive at the planning stage. Getting surface water flooding and planning right now turns…
Posted on 1st June, 2026
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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BREEAM Flood Risk Assessments Explained
BREEAM is the leading sustainability standard for UK buildings, and how a scheme handles flood risk is one of the things it scores. A BREEAM flood risk assessment is a site-specific study of a development's flood risk, written so the…
Posted on 25th May, 2026
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BREEAM
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Drainage
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Flood Risk Assessment
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Pol 03
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Groundwater Flood Risk and Planning Applications: What Developers Need to Submit
Key takeaways If your site needs a Flood Risk Assessment, that FRA must assess groundwater — it is not optional under the NPPF and Planning Practice Guidance. The national flood maps do not show groundwater. Screen with the BGS Susceptibility…
Posted on 22nd May, 2026
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Drainage
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Flood Risk Assessment
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Planning
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News & Updates
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Understanding Flood Risk
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EA SWIM Explained: Building a Business Case for Small-Scale SuDS Investment
The Surface Water Investment Model (SWIM) is an Environment Agency approach, published on 18 May 2026, for building a business case to invest in many small sustainable drainage features across a wide area, rather than one large scheme, so their…
Posted on 19th May, 2026
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Drainage
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SuDS
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SWIM
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Policy & Legislation
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Understanding Flood Risk
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Padel Court Drainage and Flood Risk: What the Planning System Actually Asks For
Padel court drainage is the part of a padel planning application that almost nobody scopes, because the court is built to drain and everyone assumes that settles the question. It does not. The LTA's own construction guidance specifies a porous…
Posted on 12th May, 2026
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Drainage
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Flood Risk Assessment
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NPPF
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Planning
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SuDS
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Policy & Legislation
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Understanding Flood Risk
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Do you need a flood risk assessment to convert a house into flats?
Usually, yes. A flood risk assessment when converting a house into flats is required wherever the site sits in Flood Zone 2 or 3, and in a growing number of Flood Zone 1 cases too. Flats are still homes, so…
Posted on 7th May, 2026
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Flood Risk Assessment
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NPPF
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Planning
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Understanding Flood Risk
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Fens 2100+ explained: what the Environment Agency’s evidence actually says
Fens 2100+ is the Environment Agency's long-term flood risk and water management programme for the Lincolnshire and Cambridgeshire Fens, run in partnership with Internal Drainage Boards, local authorities and water companies. In April 2026 it published a summary baseline report,…
Posted on 28th April, 2026
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Flood Defence
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Natural Flood Management
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News & Updates
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Understanding Flood Risk
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Sponge cities in the UK: what the idea now means for planning and drainage
Sponge cities are urban areas built to absorb, store and slowly release rainfall instead of piping it away as fast as possible. The phrase came out of China a decade ago. In Britain it has mostly been discussed as something…
Posted on 24th April, 2026
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CIWEM
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Natural Flood Management
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News & Updates
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Understanding Flood Risk
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From 6-Hour Warning to Spade in Ground: What SWFFIP Means for Planning
On 16th April the Flood Forecasting Centre published the results of SWFFIP, the Surface Water Flood Forecasting Improvement Project. The programme brings two models into fuller operational use: the Surface Water Flooding Hazard Impact Model (SWFHIM), which has been running…
Posted on 21st April, 2026
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NaFRA2
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SuDS
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News & Updates
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Understanding Flood Risk
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Groundwater Monitoring for Planning: Requirements, Timing and Delays
Groundwater monitoring for planning is the process of measuring how the water table beneath a site rises and falls over the seasons, usually to prove that an infiltration-based drainage scheme will actually work. It is most often needed where Sustainable…
Posted on 14th April, 2026
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Understanding Flood Risk
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Source Control in UK Drainage: SuDS at Plot Level
Source control means managing rainfall as close as possible to where it lands, before it has a chance to run off into the wider drainage network. It sits at the very top of the SuDS hierarchy, and in principle it…
Posted on 9th April, 2026
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SuDS
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The barn or the field? Flood risk for holiday lets, cabins and farm diversification
A holiday let flood risk assessment is required for any permanent holiday unit in Flood Zone 2 or 3, and for units in Flood Zone 1 on a site of a hectare or more, in a critical drainage area, or…
Posted on 6th April, 2026
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Flood Risk Assessment
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NPPF
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Planning
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Understanding Flood Risk
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What Drainage Information Is Needed for Planning Permission?
For years it was standard practice to secure surface water drainage by planning condition and work up the detailed design after permission was granted. That route still exists. What has changed is how much a planning application has to demonstrate…
Posted on 2nd April, 2026
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The Land Use Framework and flood risk: what it actually changes
The Land Use Framework is the government's first national statement of how England's land should be shared between housing, farming, energy and nature. Defra published it on 18 March 2026, and it is built on flood figures that ought to…
Posted on 20th March, 2026
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Sewage Capacity and Planning: Why Water Infrastructure Now Decides What Gets Built
Channel 4's Dirty Business was reviewed as a "blast of controlled fury" aimed at Britain's water industry. The drama was about sewage. The consequence for anyone trying to build is narrower and far more practical: in parts of England, sewage…
Posted on 25th February, 2026
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What Is Pluvial (Surface Water) Flooding? Causes, Risks and Planning Implications
Surface water flooding, also called pluvial flooding, happens when rainfall lands faster than the ground can absorb it and faster than drains and watercourses can carry it away, so water runs across the surface and collects in low points. That…
Posted on 18th February, 2026
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The CIRIA SuDS Manual (C753): What It Is and How to Use It in 2026
The CIRIA SuDS Manual (C753) is the UK's principal design guide for sustainable drainage systems: 968 pages covering how SuDS should be planned, designed, built, operated and maintained. CIRIA published it in November 2015 to replace the original 2007 manual,…
Posted on 26th January, 2026
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Why Lincolnshire Is Trialling a New Approach to Flood Warnings
In parts of Lincolnshire, flooding is a familiar experience that does not always come with a warning. Streets flood, gardens fill, groundwater emerges, and yet many locations sit outside the areas where the national warning service is designed to operate.…
Posted on 23rd January, 2026
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Soils, Flooding and Resilience | World Soil Day
World Soil Day, observed each year on 5th December, highlights the critical importance of soils to environmental systems that are often taken for granted. Led by the UN Food and Agriculture Organization through the Global Soil Partnership, it focuses global…
Posted on 5th December, 2025
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Runways Underwater: The 2000 Crawley and Gatwick Floods
The Crawley and Gatwick floods of November 2000 saw the Gatwick Stream and the wider Upper Mole catchment overwhelm homes, roads and even the runways at one of the country's busiest airports. They were one local chapter of the wettest…
Posted on 4th November, 2025
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Sediment ponds: what the Loughborough study shows
Sediment ponds are small excavated basins, often no bigger than five metres square, that hold back muddy runoff at the edge of a field so the soil it carries settles out before it reaches a ditch or a river. Research…
Posted on 31st October, 2025
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Paving Over Gardens: Flood Risk and the Rules You Need to Know
Paving over gardens is one of the quiet drivers of urban flooding in the UK. When grass and planting are replaced with concrete, tarmac or block paving, rainwater can no longer soak into the ground. It runs off into drains…
Posted on 30th October, 2025
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Flood Resilience in England: A Wake-Up Call
Flooding in England is no longer a localised hazard — it is a national systems challenge. The House of Commons Environmental Audit Committee’s latest report, Flood Resilience in England (HC 550, October 2025), delivers a blunt assessment: the country remains…
Posted on 29th October, 2025
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Arun’s SuDS Design Checklists: From Outline Application to Occupation
The Arun SuDS design checklists are five separate documents, published by Arun District Council in October 2025, and between them they govern a scheme from its first outline drawing to the day someone moves in. They align the district with…
Posted on 27th October, 2025
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Integrating Rainwater Harvesting into SuDS Design
Rainwater harvesting in SuDS design sits in an odd position. Collection for non-potable use is Priority 1 in the national discharge hierarchy, ahead of infiltration, a watercourse and any surface water or combined sewer. Yet on most planning applications the…
Posted on 24th October, 2025
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Green SuDS: Nature-Based Drainage in Modern Planning
Green SuDS are nature-based drainage features — swales, rain gardens, basins, green roofs and wetlands — that manage rainwater using vegetation and soil rather than buried pipes and tanks. Across England's planning system they have become the preferred form of…
Posted on 22nd October, 2025
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Planning for Flood Risk: The NPPF Explained
The NPPF is the National Planning Policy Framework: the government's planning policy for England, which councils apply when they decide planning applications and prepare local plans. The current Framework was published on 17 August 2026 and replaces every edition issued…
Posted on 16th October, 2025
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Early SuDS Planning: CIRIA C823F and What the 2026 NPPF Now Requires
Early SuDS planning means settling the surface water question at land acquisition and site appraisal, before roads, levels and plot positions are fixed. Since 17 August 2026 that is no longer only good practice. CIRIA's guide Enabling development: Getting SuDS…
Posted on 6th October, 2025
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Ofwat Abolished: What the Cunliffe Review Means for Planning
The Cunliffe review made 88 recommendations for the water sector in England and Wales, and the one everybody remembers is the abolition of Ofwat. Fourteen months on, the picture is more mixed than the headlines suggested. Government has accepted the…
Posted on 21st July, 2025
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Met Office Flood Warnings: Who Actually Issues Them
The Met Office does not issue flood warnings. That one fact clears up most of the confusion behind the phrase, because a search for Met Office flood warnings almost always ends up somewhere else. The Environment Agency issues flood alerts…
Posted on 7th July, 2025
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What is BS 6297 infiltration testing for foul drainage fields?
BS 6297 infiltration testing measures whether the ground on a site can absorb and treat effluent safely, and it is what decides whether a drainage field is a workable way to deal with foul drainage where there is no mains…
Posted on 26th June, 2025
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National Standards for Sustainable Drainage Systems (SuDS): What They Require in 2026
The National Standards for Sustainable Drainage Systems are Defra's design rules for how surface water is managed on new development in England. Defra published them on 19 June 2025 and updated them on 30 July 2025, replacing the thin 2015…
Posted on 20th June, 2025
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Thames Water Crisis 2026: Sewage, Capacity and Flood Risk by Area
The Thames Water crisis has moved a long way since the record fine of May 2025, and the part that matters most to anyone building in the Thames Valley is no longer the debt. It is capacity. Ofwat's investigation found…
Posted on 28th May, 2025
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What the 2025–30 London Surface Water Strategy Means for Planning
As climate change accelerates and urban environments become denser, cities around the world face mounting challenges in managing water. Nowhere is this truer than in London, where the convergence of ageing infrastructure, rising population pressures, and increasingly erratic weather patterns…
Posted on 22nd May, 2025
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Why Hosepipe Bans Happen, and What Planning Can Do
Hosepipe bans happen when a water company decides it is facing a serious shortage of water for distribution and uses a statutory power to prohibit a list of outdoor uses. The trigger is rarely one dry month. It is the…
Posted on 19th May, 2025
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Ordinary Watercourse Consent (OWC): The Complete Guide
Ordinary watercourse consent (OWC) is the written permission you need under Section 23 of the Land Drainage Act 1991 before carrying out any work that would obstruct or alter the flow of an ordinary watercourse: a stream, ditch, culvert or…
Posted on 28th February, 2025
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Septic tank regulations in England: the General Binding Rules in 2026
The General Binding Rules are the statutory conditions that let a septic tank or a small sewage treatment plant discharge legally in England without an environmental permit. There are 23 of them. Meet every rule that applies to your discharge…
Posted on 28th February, 2025
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What Is a Surface Water Drain? Where Yours Goes and Who Owns It
A surface water drain carries rainwater away from your roof, driveway and garden. It is a separate system from the foul drain that takes waste from your sinks and toilet, and it usually ends in one of three places: a…
Posted on 26th February, 2025
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Foul, Surface Water and Combined Sewers: How to Tell Them Apart
A foul sewer carries wastewater to treatment. A surface water sewer carries rainwater to a watercourse or an outfall. A combined sewer carries both in one pipe, and spills to a watercourse through a storm overflow when it fills. Those…
Posted on 25th February, 2025
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LiDAR Data in the UK: A Complete Guide for Flood Risk and Drainage
LiDAR data in the UK is free, national in coverage, and more widely misunderstood than any other dataset in flood risk assessment and drainage strategy practice. The Environment Agency publishes elevation models covering roughly 99% of England under the Open…
Posted on 15th November, 2024
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What is GIS? A UK Guide for Flood Risk and Drainage
GIS stands for geographic information system. It is software that holds map features and the data attached to them together, so that questions about a place can be answered by analysis instead of by eye. Anything with a location can…
Posted on 8th November, 2024
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Water Companies and the Planning Process: A Developer’s Guide
Water companies and the planning process are closely tied, even though the water company rarely appears on a decision notice. When you develop a site, your regional water and sewerage company is the body that confirms whether the network can…
Posted on 2nd September, 2024
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Lead Local Flood Authority (LLFA): What It Is and Which Is Yours
A Lead Local Flood Authority (LLFA) is the county council or unitary authority responsible for managing local flood risk across its area: surface water, groundwater and ordinary watercourses. There are 153 of them in England. On major planning applications the…
Posted on 26th August, 2024
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Does Glastonbury flood? Why Worthy Farm turns to mud
Does Glastonbury flood? Yes, though almost never because a river burst its banks. Worthy Farm sits in a shallow valley on clay with a watercourse through the middle, and what turns the site to mud is rain arriving faster than…
Posted on 22nd June, 2017
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Communities Affected by Groundwater Flooding in the UK
Groundwater flooding is not spread evenly across the country. The areas affected by groundwater flooding cluster in a narrow band of communities sitting on or just downstream of the Chalk, and the same villages tend to flood again and again:…
Posted on 29th September, 2015
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