Where we work
We are drainage engineers and civil engineering designers working across Greater Manchester and Lancashire. We have delivered 14 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 the Greater Manchester authorities, Lancashire County Council and Liverpool City Region asks for, and what the ground in Greater Manchester and Lancashire will actually do.
Our projects in Greater Manchester and Lancashire, 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 Greater Manchester and Lancashire
- Drainage design in Greater Manchester and Lancashire — surface water and foul drainage strategies, attenuation, SuDS and outfall design, sized for your site and your discharge rate.
- 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.
- Highway design — access, visibility splays, turning heads and adoptable road design, including Section 38 and Section 278 agreements.
- Percolation testing — BRE 365 soakaway testing across Greater Manchester and Lancashire, arranged through PT (West Midlands) Ltd so the design and the testing come from one place.
Ground conditions in Greater Manchester and Lancashire
Greater Manchester, Lancashire and Merseyside sit on Sherwood Sandstone and Coal Measures, but during the last ice age the sandstone was buried under boulder clay and glacial till, which is exactly why the region has such poor natural drainage and its mosses and meres. Superficial deposits thicken to over 80 metres in buried channels cut into the bedrock, so what is mapped underneath may be nowhere near what a soakaway would reach.
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 ground model for Greater Manchester. 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.
Greater Manchester and Lancashire at a glance
- Lead local flood authority
- the Greater Manchester authorities, Lancashire County Council and Liverpool City Region
- Postcode areas
- BB, BL, L, LA, M, OL, PR, SK, WA, WN
- Projects delivered here
- 14
- Statutory consultee
- Yes, on surface water for major development
- Percolation testing
- BRE 365, via PT (West Midlands) Ltd
- Case studies
- 3
What your lead local flood authority expects
Lancashire runs a chargeable pre-application advice service that also covers ordinary watercourse consent, which is the consent most often missed. Works that obstruct or alter an ordinary watercourse need it in addition to planning permission, and finding that out late can stop a job on site.
Advice covers the surface water elements of a flood risk assessment and the drainage strategy itself, against the national SuDS standards. Greater Manchester’s ten boroughs and the Liverpool City Region authorities each act as their own lead local flood authority, so requirements shift from borough to borough here.
Source: your lead local flood authority. Requirements and ground conditions both change — we check them at the start of every job.
Flood risk assessments in Greater Manchester and Lancashire
Drainage is the bulk of what we do, but in Greater Manchester and Lancashire a large share of it comes with flood risk assessment attached — because the Mersey and Irwell catchments, and heavy rainfall on ground that does not drain, make flood risk an early question.
A site-specific flood risk assessment applies the sequential and exception tests, works out the flood levels your site will actually see over its lifetime including an allowance for climate change, and sets finished floor levels, safe access and egress against them. your lead local flood authority and the Environment Agency both look at it, and the commonest reason one comes back is that it assessed fluvial risk and ignored surface water.
We do this as part of the same job, so the flood risk assessment and the drainage strategy agree with each other rather than being written by two firms who never spoke. More on flood risk assessment.
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 your lead local flood authority.
- 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 your lead local flood authority 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 Greater Manchester and Lancashire
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 Greater Manchester and Lancashire
Past project locations here include Wigan, Heald Green, Bury, Rochdale, High Lane, A Macclessfield Road and Brigsteer.
Questions we get asked in Greater Manchester and Lancashire
Do you need to be local to do this work?
No. It is done from survey data, ground investigation and your lead local flood authority’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?
the Greater Manchester authorities, Lancashire County Council and Liverpool City Region. 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 definitely need a flood risk assessment?
If your site is in Flood Zone 2 or 3, or is over a hectare in Zone 1, yes. Smaller sites in Zone 1 can still need one where there is a record of surface water flooding — and in Greater Manchester and Lancashire there often is. Send us the address and we will check the maps before you pay for anything.
Can a flood risk assessment get a refusal overturned?
Sometimes. An FRA that applies the sequential and exception tests properly, and shows safe access, egress and finished floor levels, can answer the objection that caused the refusal. It depends entirely on why it was refused.
What holds a drainage scheme up?
Usually the ground testing, and where one is needed, the response time from your lead local flood authority 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 Greater Manchester and Lancashire 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.