Where we work
We are drainage engineers and civil engineering designers working across Oxfordshire. We have delivered 19 projects here — drainage strategies, SuDS reports, flood risk assessments and highway design, prepared for planning and taken through to approval.
You do not need a consultant down the road from your site. This is desk work built on survey data, ground testing and the local authority’s own standards. What matters is that whoever does it knows what Oxfordshire County Council asks for, and what the ground in Oxfordshire will actually do.
Our projects in Oxfordshire, in red, against the rest of England. One dot per project, placed within its postcode area rather than at the exact site. Zoom out for the full picture, or ctrl and scroll to zoom.
Civil engineering design in Oxfordshire
- Drainage design in Oxfordshire — surface water and foul drainage strategies, attenuation, SuDS and outfall design, sized for your site and your discharge rate.
- Highway design — access, visibility splays, turning heads and adoptable road design, including Section 38 and Section 278 agreements.
- Flood risk assessments — site-specific flood risk assessments for sites in Flood Zones 2 and 3, and for sites over a hectare in Zone 1.
- SuDS design — sustainable drainage design and the SuDS statement your planning authority expects, with the drainage hierarchy worked through in order.
- Percolation testing — BRE 365 soakaway testing across Oxfordshire, arranged through PT (West Midlands) Ltd so the design and the testing come from one place.
Ground conditions in Oxfordshire
Oxfordshire stacks up as Oxford Clay, a belt of Corallian limestone running across the south of the county from Shrivenham to Oxford, and Chalk further south, with Thames terrace gravels along the valley. The gravels can take infiltration; springs frequently mark the line where they meet the Oxford Clay beneath, and that contact is worth knowing about before a soakaway is designed over it.
None of that tells us what is under your plot, and no report should pretend otherwise. It tells us what to expect, what to test for, and whether to plan for infiltration or for attenuation and a restricted discharge. A percolation test to BRE 365 settles it, and it is cheaper to do that before the design than to redesign afterwards.
Source: BGS Earthwise, London and the Thames Valley. Requirements and ground conditions both change — we check them at the start of every job.
The drainage hierarchy
- 1InfiltrationSoakaway or infiltration basin, if the ground takes it
- 2WatercourseDischarge to a surface water body, usually rate-restricted
- 3Surface water sewerWhere a public surface water sewer exists and has capacity
- 4Combined sewerLast resort, and increasingly refused outright
Every scheme has to work down this list in order, and show why each option above the chosen one was ruled out. The ground is what decides whether you get to stop at step one.
Oxfordshire at a glance
- Lead local flood authority
- Oxfordshire County Council
- Postcode areas
- OX
- Projects delivered here
- 19
- Statutory consultee
- Yes, on surface water for major development
- Percolation testing
- BRE 365, via PT (West Midlands) Ltd
- Case studies
- 6
What Oxfordshire County Council expects
Oxfordshire publishes its own Local Standards for surface water drainage and updates them — the current revision dates from 2026. Designing to the national standards alone is not enough here; the county’s local standards are what the scheme is assessed against.
The county council secures maintenance arrangements for the lifetime of the development through planning conditions or obligations, so a maintenance plan is expected alongside the design rather than after it.
Source: Oxfordshire County Council. Requirements and ground conditions both change — we check them at the start of every job.
Highway design in Oxfordshire
Drainage is the bulk of what we do, but in Oxfordshire a large share of it comes with highway design attached — because growth around Oxford and the science corridor brings access, adoption and Section 278 work with it.
Access and visibility are usually settled before drainage, because they constrain the layout itself. We design accesses, visibility splays, turning heads and adoptable carriageways, and take them through Section 278 works to the existing highway and Section 38 adoption of new roads with the highway authority for Oxfordshire. Leaving this late is expensive: it can mean redrawing the site plan and the drainage with it.
We do this as part of the same job, so the highway design and the drainage strategy agree with each other rather than being written by two firms who never spoke. More on highway design.
What you need, and when
The work is not one document handed in once. It arrives in stages, and sending the wrong level of detail at the wrong stage is one of the commonest reasons an application stalls with Oxfordshire County Council.
- Outline application. A strategy showing the principle: where the water goes, roughly what it will take, and that the site can be drained at all. Detailed calculations are not expected yet, but a strategy that ignores the discharge hierarchy will be questioned.
- Full application. The full surface water and foul scheme with calculations, layout, attenuation volumes and the discharge rate you are asking for, evidenced.
- Reserved matters. The detail that was reserved at outline, now built out against the approved strategy — and it has to match it.
- Discharge of conditions. The final submission against the wording of the condition itself, with the maintenance and management arrangements Oxfordshire County Council asks for. This is the stage most people reach us at, often with a condition already imposed.
Where the work lands
- OutlineDrainage strategy: the principle, not the detail
- FullFull scheme, with calculations and discharge rate
- Reserved mattersThe detail, matching the approved strategy
- DischargeSubmission against the condition wording itself
Most people reach us at the last step, with a condition already imposed. That is fine — it is just cheaper to have got the strategy right at the first.
Typical conditions we discharge in Oxfordshire
Exact wording varies between officers and between applications, but conditions on sites here almost always fall into three shapes:
- Surface water drainage. “No development shall commence until a detailed surface water drainage scheme, based on sustainable drainage principles and an assessment of the hydrological and hydrogeological context of the development, has been submitted to and approved in writing by the Local Planning Authority.” This is the one that needs the percolation results and the attenuation calculations.
- Foul drainage. A scheme for foul water disposal, agreed before occupation — straightforward on a mains connection, considerably less so on a package treatment plant or where the sewer is at capacity.
- Management and maintenance. A plan setting out who maintains the drainage for the lifetime of the development, and how. Often overlooked, and a common reason a discharge application comes back.
If you have a condition in front of you, send us the wording. We will tell you what it actually requires, before you commit to anything. There is a fuller guide to drainage planning conditions if you want to read up first.
Our work in Oxfordshire
Past project locations here include Oxford, Oxfordshire, Maplewood Barn, Stanton St John, Churchill, Bampton and – Phase.
- A single dwelling in Oxfordshire
- A barn replacement in Stoke Talmage
- A visitor attraction in Chipping Norton, Oxfordshire
- A single dwelling in Oxfordshire
- A barn in Oxfordshire
- An extension in Oxford
Questions we get asked in Oxfordshire
Do you need to be local to do this work?
No. It is done from survey data, ground investigation and Oxfordshire County Council’s own standards, none of which require us to be nearby. Being the right distance from your site has never discharged a condition; knowing what the authority wants has.
Who is the lead local flood authority for my site?
Oxfordshire County Council. They are a statutory consultee on surface water drainage for major development, and they set the local standards and the discharge rate your scheme is judged against.
Do I need a Section 38 or a Section 278 agreement?
Section 38 covers a new road you want adopted; Section 278 covers works to an existing highway, such as a new access. Many schemes in Oxfordshire need both, and they run to different timescales.
How early does highway design need to start?
Earlier than most people expect. Access and visibility often constrain the layout itself, so settling them late can mean redrawing the site plan and the drainage with it.
What holds a drainage scheme up?
Usually the ground testing, and where one is needed, the response time from Oxfordshire County Council or the water company — not the design itself. Getting the testing booked early is the single biggest thing you can do to keep a scheme moving.
I already have a planning condition. Can you deal with it?
Yes, and it is most of what we do. Send us the condition wording and the site address and we will tell you what is needed to discharge it.
Get a quote for your Oxfordshire site
Send us the site address and the condition wording, or the planning reference, and we will tell you exactly what is needed. If you do not need us, we will say so.