Surface Water Drainage Design
Engineered Surface Water Drainage for Development Projects
This specialist package forms part of RIDA’s wider drainage design service. It addresses runoff, storage, conveyance, discharge controls, SuDS integration and coordinated drainage information. The work can support a planning submission, discharge of a drainage condition or detailed development design. Projects needing wider technical advice can use RIDA’s drainage consultancy service.
Get A Free No Obligation QuoteWhat You Will Receive
Technical deliverables and practical use
| Technical deliverable | Practical use |
|---|---|
| Design statement recording the drainage basis, constraints and hierarchy | Supports review of the proposed solution at the agreed project stage. |
| Hydraulic calculations or model outputs for runoff, network capacity, storage and flow controls | Provides evidence against the agreed design criteria. |
| Attenuation, outfall and discharge-control design | Records storage volumes, flow rates and connection assumptions. |
| Drainage layouts, levels, schedules, exceedance routes and relevant details | Supports planning, design-team coordination and construction documentation. |
Design Scope and Approval Considerations
The design scope reflects impermeable areas, runoff and discharge limits, infiltration potential, outfall availability, site levels, attenuation, network capacity, exceedance routing, design storms and applicable climate-change allowances.
Planning-stage recommendations may call for a separate drainage strategy for planning. Projects centred on source control, treatment, amenity and biodiversity may require broader sustainable drainage systems design. A surface-water flood-risk assessment addresses flood-risk evidence rather than the engineered drainage package.
Official design references
Project criteria are checked against the National standards for sustainable drainage systems, Approved Document H: drainage and waste disposal where applicable, and current flood risk climate change allowances. Local validation criteria and consultee requirements are reviewed for your site.
Information Needed to Quote and Start
- Site address or red-line boundary — to check the site-specific planning and drainage context.
- Proposed layout, levels and impermeable areas — to define runoff and design scope.
- Topographical survey — to establish levels, flow routes and outfall feasibility.
- Ground, infiltration, utility and drainage records — to assess constraints and connection options.
- Planning reference, consultee comments and target date — to confirm submission requirements and programme.
Surface Water Drainage Design FAQs
Can RIDA prepare surface water drainage calculations and drawings for planning?
Yes. The agreed package can include calculations, storage and flow-control design, layouts and a supporting statement for planning or condition discharge. Submission requirements remain authority-dependent.
What information do you need to quote for a surface water drainage design?
Send the site boundary, proposed plans and levels, topographical data and any drainage, ground, infiltration or outfall information. These records define the scope and fee.
What is the difference between a drainage strategy and detailed surface water drainage design?
A strategy sets out the proposed planning-stage approach. Detailed design develops the hydraulic calculations, storage, controls, levels, network and drawings for the agreed project stage.
What happens if infiltration testing or additional hydraulic modelling is required?
RIDA will identify the missing evidence, explain why it is needed and confirm any change to scope before further work starts.
Discuss Your Surface Water Drainage Design
Send your site address, plans, levels and available drainage information. RIDA will review the material and provide a proposed scope, programme and fee for planning, condition discharge or detailed design.
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