Service
Sewerage & Drainage System Design
We design sanitary, combined and stormwater sewer networks that are sized against real flow and rainfall data, not assumptions, and detailed to a level your contractor can build from without back-and-forth.
Photo: Dmitry Makeev, CC BY-SA 4.0, via Wikimedia Commons
Undersized sewers surface as flooding and surcharging years after installation; oversized ones waste budget. We size gravity and pressurised sewer networks using flow modeling that reflects catchment area, population equivalents and local rainfall intensity data, then verify capacity under design storm events.
Work covers new sanitary sewer networks, stormwater drainage systems, combined sewer overflows, pumping stations and rehabilitation of existing networks, delivered as coordinated 2D/3D documentation.
What this includes
- •Sanitary sewer network design and capacity verification
- •Stormwater drainage and attenuation system design
- •Combined sewer system design and overflow structure sizing
- •Sewage pumping station and rising main design
- •Sustainable drainage (SuDS) and infiltration system integration
- •Existing network capacity assessment and rehabilitation design
How we work
- 01
Catchment analysis
Population equivalents, impervious area mapping and rainfall data for the relevant return period.
- 02
Flow & capacity modeling
Gravity and pressurised network sizing, verified under design storm and peak flow conditions.
- 03
2D/3D design
Layout, profiles and manhole/structure detailing in AutoCAD, Revit or ArchiCAD.
- 04
Documentation & handover
Calculation reports and drawing sets ready for permitting, tender and construction.
Frequently Asked Questions
Do you design both sanitary and stormwater systems, or only one?
Both. We design sanitary sewer networks, stormwater drainage and combined systems, and can integrate all three where a site requires a coordinated solution.
How do you determine pipe sizing for stormwater networks?
Sizing is based on catchment area, surface type and local rainfall intensity-duration-frequency data for the specified design storm return period, verified with hydraulic capacity checks rather than fixed tables alone.
Can you assess whether an existing sewer network has enough capacity for a new development?
Yes, capacity assessment of existing networks against added flow from a proposed development is a common starting point before we design any extension or upgrade.
Do you provide 3D models for clash detection with other services?
Yes, we deliver coordinated 3D models in Revit or ArchiCAD so drainage routing can be checked against water, gas, electrical and other buried services before construction.
Ready to talk through your project?
Send us the basics of what you need designed or calculated, and we will come back with scope and timeline.