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Highway Drainage Solutions & SuDS Installation
We design and install highway drainage systems that prevent flooding, protect road surfaces, and meet planning requirements. Traditional systems or SuDS – one partner handling everything from design through adoption.
Highway drainage for councils, developers, and infrastructure projects requiring compliance
Every highway depends on effective drainage you never see. Until it fails.
When surface water isn’t managed right, you get flooded carriageways, water ingress accelerating pothole formation, planning refusals, and adoption nightmares dragging on for months whilst your capital sits locked up.
Get drainage designed and installed to adoptable standards
You need systems that handle 1-in-100-year rainfall events, meet environmental regulations, and get signed off by highway authorities or water companies without endless remediation rounds.
We deliver this across the South West, South Wales, and Thames Valley. Highway drainage expertise backed by NHSS accreditation, with full understanding of both English planning requirements and Welsh SAB approval processes.
What we can deliver for your site...
Why highway drainage fails - and why it destroys programmes and budgets
The design and installation failures causing problems
There's a better way...
Drainage designed right, installed to adoptable standards. One partner managing the full lifecycle
Proper investigation before design:
Infiltration testing, groundwater assessment, soil analysis, outfall surveys. We design systems based on what's actually underground, not guesses or desktop assumptions.
Compliant design meeting adoption standards:
Section 104 specifications, highway authority requirements, SuDS standards. Systems designed for approval first time, not endless revision rounds.
Environmental compliance built in:
Water quality treatment, pollution prevention, biodiversity enhancement where SuDS are used. Planning conditions satisfied, environmental consents secured.
Installation by NHSS-accredited teams:
Highway works delivered to National Highway Sector Schemes standards. Quality assured, properly supervised, inspected at every stage.
Traffic management included:
Chapter 8-compliant controls, safe working zones, minimal disruption. Highways kept operational, public safety maintained throughout.
Full adoption documentation provided:
As-builts, infiltration test results, maintenance schedules, consent certificates. Everything needed for Section 38, Section 104, or SAB approval. Ready at handover.
Why councils and developers choose Highways Plus
You’re managing infrastructure that must work for decades. And it must satisfy regulators who’ll reject systems that don’t meet standards.
What sets us apart
We understand both regulatory regimes:
English planning and Lead Local Flood Authority consultation processes, Welsh SAB approval requirements. Whether you’re in Somerset, South Wales, or Thames Valley, we know what’s needed for approval.
Highway adoption integrated from day one:
Section 38 highway schemes with drainage designed as part of the adoptable infrastructure. Section 278 junction improvements with upgraded drainage. One contractor, one adoption process.
SuDS and traditional systems both available:
Not all sites suit infiltration. We design whichever approach works – permeable paving and swales where ground conditions allow, piped systems where they don’t.
Proper investigation eliminates surprises:
Infiltration testing, percolation tests, groundwater monitoring during winter. We design based on actual site conditions, not desktop assumptions.
Full lifecycle service:
Design, approvals, installation, testing, documentation, handover. You’re not coordinating drainage designers, contractors, adoption consultants separately.
Fixed-fee options available:
Backlog defect resolution for existing non-compliant drainage. Lump-sum pricing bringing systems up to adoptable standards, clearing the path to sign-off.
A clear, structured process that delivers adoptable systems
Highway drainage needs thorough investigation, compliant design, quality installation, comprehensive testing. Full documentation at every stage.
What you get...
Projects typically run through design, approval, and installation phases with testing and handover documentation provided throughout.
Typical timelines: 6-10 weeks for standalone drainage installations, 12-16 weeks where approvals from water companies or Lead Local Flood Authorities are needed, integrated with highway construction programmes for Section 38 schemes.
Site investigation and feasibility:
Desktop studies, infiltration testing, groundwater monitoring, outfall surveys. You get a drainage strategy showing what's viable before detailed design starts.
Design and regulatory approval:
Hydraulic calculations, SuDS component sizing, Section 104 or SAB submissions. Designs approved by water companies, highway authorities, or SABs before installation.
Installation with quality assurance:
NHSS-accredited teams, traffic management, material testing, compaction checks. Drainage installed to specification with independent inspection throughout.
Testing and commissioning:
Half-drain time testing for infiltration systems, CCTV surveys of pipes, flow testing of gullies. Systems proven to perform before handover.
Adoption documentation and handover:
As-built drawings, test certificates, maintenance schedules, consent documentation. Everything required for Section 38, Section 104, or SAB adoption provided in approved formats.
Highway drainage solutions CASE STUDY
Residential development, North Somerset
The Challenge:
- Developer's 47-unit scheme had planning permission. Granted subject to SuDS condition requiring surface water management meeting Lead Local Flood Authority requirements.
- Initial drainage design by architect specified soakaways across the site. Main contractor pricing based on this approach, total drainage package estimated at £85,000.
- Then ground investigation during enabling works revealed clay subsoils. Infiltration rates below minimum viable thresholds. Soakaway design wouldn't work. Development programme stalled whilst consultants redesigned the entire drainage strategy from scratch.
Our Solution:
- Hybrid approach combining limited infiltration where ground conditions allowed with attenuated discharge to nearby watercourse where they didn't.
- Permeable paving on parking areas and private driveways (Type C with attenuation storage, not infiltration). Road surfaces traditionally surfaced with combined kerb drainage collecting runoff.
- Underground attenuation crates providing storage, releasing water gradually to watercourse under Environment Agency consent secured at 5 litres/second.
- Swales along site boundaries providing water quality treatment before discharge, satisfying Lead Local Flood Authority biodiversity enhancement requirements.
- Fixed-fee package at £78,000 including design, approvals, installation, adoption documentation - below original estimate despite redesign.
The Outcome:
- Drainage system approved by Lead Local Flood Authority within four weeks of redesign submission
- Construction programme recovered with drainage installation phased across 10 weeks
- Section 104 adoption secured six months post-completion with zero defects
- Developer avoided £25,000+ consultant redesign fees and 14-week programme delay through our integrated approach
Proven delivery of highway drainage solutions across diverse sectors
Whether you’re maintaining public highways, developing residential estates, or delivering commercial infrastructure, you need drainage systems that work reliably and get adopted without problems.
Sectors that rely on us:
Local authorities and highway authorities:
Planned drainage upgrades, emergency repairs, flooding hotspot remediation. Systems maintaining highway networks safely whilst satisfying environmental requirements.
Residential and mixed-use developers:
Section 104 sewer adoption systems, SuDS meeting planning conditions, Section 38 estate road drainage. Developments signed off without backlog defects delaying sales.
Commercial and industrial developments:
Car park drainage, logistics yard surface water management, attenuation systems for large roof areas. Cost-effective solutions meeting water company requirements.
Main contractors and groundworks specialists:
Drainage subcontract packages for highway schemes, Section 278 junction drainage, infrastructure projects. Reliable delivery keeping main programmes on track.
Infrastructure and civil engineering projects:
Road widening schemes, junction improvements, new highway construction. Drainage designed and installed to adoptable standards as part of Section 38 or Section 278 agreements.
Retail, leisure, and hospitality sites:
Car park drainage, access road surface water management, landscaping drainage. Attractive SuDS features combining functionality with aesthetics.
Your Highway drainage solutions questions, answered...
What's the difference between traditional drainage and SuDS?
Traditional systems collect surface water through gullies and pipes, discharging to sewers or watercourses. SuDS manage water where it falls using infiltration, storage, and controlled release. Mimics natural drainage whilst providing environmental benefits like water quality treatment and biodiversity. We design whichever approach suits your site conditions and regulatory requirements.
How long does drainage installation typically take?
Standalone installations: 6-10 weeks depending on complexity. Projects requiring water company or Lead Local Flood Authority approval: 12-16 weeks including design and consent periods. Emergency repairs or upgrades: mobilisation within 48 hours, completion typically within one week.
What approvals are needed for highway drainage?
In England: Lead Local Flood Authority consultation through planning system, Environment Agency consent for discharges to main rivers, water company approval for Section 104 adoptable sewers. In Wales: SAB (SuDS Approving Body) approval mandatory for developments over 100m2. We manage all approval processes as part of our service.
Can you fix existing drainage that's causing flooding?
Yes. We investigate failure causes through CCTV surveys, flow testing, infiltration assessment. Solutions range from gully cleaning and pipe repairs through to complete system redesign and installation. Emergency response available for flooding incidents affecting highway safety.
Do SuDS systems need more maintenance than traditional drainage?
Depends on design. Permeable paving needs regular sweeping and occasional pressure washing. Swales need seasonal vegetation cutting. Underground attenuation crates? Minimal maintenance if designed with access chambers. We provide maintenance schedules with every installation showing exactly what’s required and how often. No surprises.
What if ground conditions won't allow infiltration?
We design attenuation systems storing water temporarily and releasing gradually to approved outfalls. Permeable paving can be Type C (attenuation, no infiltration). Underground crates with controlled discharge. Traditional piped systems where environmental benefits aren’t achievable. Proper investigation before design prevents expensive retrofits.
How do you integrate drainage with Section 38 highway adoption?
Drainage is designed as part of the adoptable highway infrastructure. Highway authority reviews drainage alongside road construction. Single adoption agreement covering roads, footways, drainage. As-built drawings capture both surface and drainage infrastructure. One contractor managing both elements eliminates interface risks.
What documentation do you provide for adoption?
As-built drawings in CAD and GIS formats, infiltration test certificates, CCTV surveys of pipework, maintenance schedules, water company consent certificates, Environment Agency discharge consents, material test certificates, compaction records. Everything required for Section 38, Section 104, or SAB adoption provided in approved formats.
Can you handle emergency drainage repairs?
Yes. Mobilisation within 48 hours for flooding incidents or drainage failures affecting highway safety. Chapter 8 traffic management, emergency excavation permits, out-of-hours working available. Temporary repairs for immediate safety, permanent solutions programmed to suit your budget cycles.
Need drainage designed to meet adoption standards?
Book a Free, No-Obligation Highway drainage solutions Assessment
We’ll assess your site, test ground conditions if needed, identify the drainage approach that satisfies regulatory requirements whilst controlling costs, provide a written report with fixed-fee quotation.
No obligation, no sales pressure – just expert advice from NHSS-accredited specialists who’ve delivered highway drainage across hundreds of projects in the South West, South Wales, and Thames Valley.
Call or fill out our form and we'll be in touch within 24 hours.
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