If you’re planning to build, extend, or alter a property in Milton Keynes, one of the most important, yet often overlooked – aspects of your project is drainage compliance.
The city has a robust framework of rules designed to manage flood risk, protect local watercourses, and ensure long-term sustainability. Here’s a clear breakdown of what’s required and how to stay compliant.
Why Drainage Rules Matter in Milton Keynes
Milton Keynes has a complex network of rivers, brooks, and artificial drainage channels, all of which help control flood risk across a fast-growing city. To prevent surface water flooding and protect the environment, the Milton Keynes City Council enforces national drainage standards alongside its own local policies.
Whether you’re a homeowner adding an extension, or a developer planning a new site, you must design your drainage system in line with both national regulations and local council guidance.
Key Local Drainage Policies and Authorities
Lead Local Flood Authority (LLFA)
Milton Keynes City Council is the LLFA responsible for:
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Assessing surface water drainage strategies for major developments.
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Ensuring that new drainage systems (including SuDS) are properly designed and maintained.
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Approving works that could affect ordinary watercourses.
💡 Tip: Always consult the council’s Flood Risk Guidance for Developers (2022) before starting your design.
Plan:MK Local Plan (Policies FR1–FR3)
Under the Plan:MK Local Plan, development is not permitted within floodplains unless flood risk is fully managed.
New sites must include:
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Surface water attenuation (storing rainwater during storms).
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Sustainable Drainage Systems (SuDS) integrated into landscaping.
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Long-term maintenance plans to ensure ongoing operation.
National Regulations That Also Apply
Even at the local level, all drainage systems must meet the standards set out in:
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Approved Document H (Building Regulations – Drainage and Waste Disposal)
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Flood and Water Management Act 2010
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National Standards for Sustainable Drainage Systems (SuDS)
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General Binding Rules for small sewage discharges (if using septic tanks or treatment plants)
These cover everything from pipe sizing and soakaway distances to pollution prevention and proper separation of foul and surface water systems.
Working Near Watercourses
If you have a ditch, drain, or stream running through or beside your land, you’re likely a riparian owner. That means:
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You must keep the watercourse clear of blockages and debris.
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You may need Land Drainage Consent before building or altering anything within 9 metres of the bank.
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Any culverting, piping, or diversion of a watercourse without consent can lead to enforcement action.
You can apply for consent directly through the Milton Keynes Council Watercourse Management page.
SuDS and Long-Term Maintenance
Modern drainage design in MK prioritises Sustainable Drainage Systems (SuDS) – features like swales, soakaways, green roofs, and attenuation basins that help manage rainfall naturally.
To gain approval:
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Show how your SuDS design limits discharge to greenfield runoff rates.
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Provide a clear maintenance schedule – who will inspect, clean, and fund upkeep over time.
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Demonstrate resilience to climate change and extreme rainfall events.
Without a defined maintenance plan, drainage applications are often refused.
Common Permissions and Consents
| Type of Work | Permission Needed |
|---|---|
| Connecting to a public sewer | Approval from Anglian Water (Section 104 agreement) |
| Altering a watercourse | Land Drainage Consent from MK Council |
| Discharging treated water or sewage to surface water | Environment Agency permit |
| Building or extension works | Building Regulations approval including drainage layout |
| Major new developments | Full Surface Water Drainage Strategy submission |
Checklist for Compliance
Before you start, make sure you have:
✅ A surface water drainage strategy following MK’s local guidance
✅ A flood risk assessment (if your site is in a risk zone)
✅ Details of drainage ownership and maintenance
✅ Consent if working within 9m of a watercourse
✅ Approved plans for soakaways, pipes, and discharge routes
✅ Confirmation of right of discharge to sewers or watercourses
Final Thoughts
Milton Keynes is one of the most forward-thinking authorities in England when it comes to sustainable drainage. Its approach protects both new developments and existing communities from flooding, while helping preserve the city’s unique balance of green and urban space.
If you’re unsure about your drainage obligations, always consult:
Contact Drain Solutions Milton Keynes
We operate 24/7, with no call-out charge, fast response, and fixed-fee pricing starting from £110 + VAT (for basic unblocking).
Whether you’re doing a minor plumbing job, full site development, or just want to check if your drainage plan is compliant — we’re here to help.
📞 0779 1970 381
🌐 drainagemiltonkeynes.co.uk
Let us take the complexity out of drainage compliance – so you can focus on building, extending, or improving your property with confidence.
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