Estimate Flows
Phase 10 §10.3 — Wizard for sizing wastewater / water / stormwater design flows from project parameters. ← Headloss Calculator
- 1 Project type
- 2 Method
- 3 Inputs
- 4 Results
Step 1 — Project type
Pick the project category. The next step's available methods change depending on this choice.
Step 2 — Estimation method
Pick the estimation methodology. The next step's input form changes based on this choice.
Step 3 — Inputs
Fill in the project-specific inputs. Defaults match the seeded engineering reference values; override any field that doesn't fit your situation.
Optional — commercial conversions
Convert commercial uses to equivalent dwelling units + add to the count above. Example conversions:
- Small restaurant ≈ 5 EDUs
- Hotel room ≈ 0.4 EDU (100–200 gpd/room ÷ 250)
- Hospital bed ≈ 0.8 EDU (200 gpd/bed ÷ 250)
- Office (per 1000 sf) ≈ 0.5 EDU
Add one row per land-use category. Default rates from Metcalf & Eddy 5th ed. — override any value.
| Use type | Acres / units | Rate (gpd/unit) |
|---|
Enter total drainage fixture units (DFU) per the IPC/UPC code count. Hunter's probability curve converts DFU → peak GPM.
Q = C × i × A. Defaults reference ASCE Manual 37 runoff coefficients (seeded in flow_reference_data).
You already have a flow estimate. Continue to send it to the headloss calculator.
Step 4 — Results
Computed flows + a recommended pipe-size table at ~5 ft/s target velocity.
Suggested force-main / pipe size (target ~5 ft/s at peak flow)
Velocity at the peak flow shown above. The recommended size highlights the smallest standard NPS that keeps velocity in the 2–8 ft/s optimal band.
| Nominal size | Inside dia (in) | Velocity @ peak | Verdict |
|---|