The five-stage lifecycle

Design Journey

Five stages from a blank site to an adopted, maintained SuDS scheme. Quinnsite covers the full lifecycle of a UK drainage scheme. Use this page as your roadmap: each stage explains what to decide, which tool to open, and which standard you are discharging against before you move on.

New to Quinnsite? It runs in your browser and saves locally. Set up a project first, so every stage's calculations and reports collect in one place. The step-by-step guide shows you how. Getting Started →
1
Stage 1 · Baseline

Understand the site before you draw anything.

A drainage design is only as good as the baseline underneath it. Map the catchment, classify the soils, run your infiltration tests, pick the right climate-change uplift and set the greenfield runoff rates you will have to match at discharge.

What you'll leave this stage with

  • Site boundary, impermeable area, receiving waterbody and discharge point
  • Soil classification, infiltration rate and groundwater vulnerability
  • QBAR / Q1 / Q30 / Q100 greenfield runoff baseline (IH124 or FEH)
  • Climate-change uplift chosen against the management catchment
  • Initial feasibility screen: which SuDS components are realistic here
Discharging against CIRIA C753 Ch. 3 & 25 · BRE Digest 365 · IH124 / FEH · EA CC 2022 · NSTS S1–S3 baselines.
Next up
Stage 2: Plan the management train
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2
Stage 2 · Management train

Plan source control, interception and treatment before storage.

Under NSTS S1 every development must intercept the first 5 mm of rainfall. Under S4 and S5 the scheme must demonstrate a treatment train matched to the pollution hazard of the catchment. Plan the chain of source-, site- and regional-control components here, before you start sizing tanks.

What you'll leave this stage with

  • Interception strategy for the 5 mm event (S1)
  • Treatment-train mitigation index vs pollution hazard (S4)
  • Receiving waterbody sensitivity & WFD screening outcome
  • A ranked shortlist of source / site / regional control components
Discharging against NSTS S1, S4, S5 · CIRIA C753 Ch. 4 & 26 · WFD 2017 assessment · Water quality pollution hazard matrix.
Next up
Stage 3: Size the components
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3
Stage 3 · Component sizing

Size storage, attenuation and every component in the train.

Once the train is planned, each component gets sized against the greenfield discharge rates and the chosen design event. Attenuation, permeable paving, bioretention, swales, basins, ponds and wetlands all live here.

What you'll leave this stage with

  • Attenuation volume matched to Q1 / Q30 / Q100 + CC uplift
  • Storage geometry, freeboard and half-drain-time checks
  • Sizing for every SuDS component in the train
  • Retention vs detention split + reuse opportunities
Discharging against NSTS S2, S3 · CIRIA C753 Ch. 6–23 · BS EN 16941-1 (RWH) · BS 8582 (surface water design).
Next up
Stage 4: Design the network
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4
Stage 4 · Network & hydraulics

Connect the components with a network that doesn't surcharge.

Pipes, manholes, gutters, channels, outfalls, pumps and exceedance routes. Check hydraulic grade lines against finished levels, pick orifice sizes to control discharge and design the overflow path for events that exceed the design standard.

What you'll leave this stage with

  • Pipe sizes & gradients with self-cleansing velocity
  • Manhole sizing and drop chambers against depth class
  • Hydraulic grade line vs cover/finished levels
  • Orifice geometry to hit the target discharge rate
  • Exceedance route for the 1-in-100 + CC event (S6)
Discharging against NSTS S6 · CIRIA C753 §16-17 · BS EN 752 · BS EN 1433 · SSG sewer design.
Next up
Stage 5: Prove, deliver & maintain
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5
Stage 5 · Compliance, delivery & O&M

Prove the scheme, cost it, build it and hand it over.

Assemble the S1–S7 case, write the Flood Risk Assessment, cost the whole-life scheme, demonstrate biodiversity and amenity value, and produce the maintenance and adoption package the local authority or water company will accept.

What you'll leave this stage with

  • S1–S7 compliance report ready for the SAB / LPA
  • FRA evidence pack & exceedance diagrams
  • Capex + 30-year whole-life cost with maintenance profile
  • Embodied carbon, BNG uplift & amenity scoring
  • Construction management plan, maintenance plan, adoption register
Discharging against NSTS S7 · CIRIA C753 Ch. 27 & 32 · Defra BNG metric · Sewerage Sector Guidance (adoption).

Open the calculator that matches your stage.

Every tool opens with the same layout: inputs on the left, live results on the right, downloadable report at the bottom. Pick where you are today, and the workflow continues from there.