Design basins faster with clear, practical inputs today. Check geometry, slopes, and storage allowance quickly. Download summaries, share numbers, and keep crews aligned daily.
| Method | Key inputs | Provided volume | Drainage area | Storage rate | Freeboard | Recommended volume |
|---|---|---|---|---|---|---|
| Rectangular with side slopes | Lb=12 m, Wb=6 m, D=2 m, 2H:1V | ~329.324 m³ | 2.0 ha | 125 m³/ha | 10% | 275 m³ |
| Rectangular (vertical sides) | L=18 ft, W=10 ft, D=6 ft | 1,080 ft³ | — | — | — | — |
| Circular with side slopes | r1=14 ft, D=5 ft, 3H:1V | ~279.834 yd³ | 1.5 acre | 67 yd³/acre | 15% | 115.5 yd³ |
Sediment basins are controls that protect downstream infrastructure during earthworks. This calculator supports sizing checks by turning measured dimensions into storage volume, then comparing that capacity against a project storage target and freeboard allowance. Use it during planning, field verification, and inspection closeout to keep capacity traceable. Align basin IDs with drainage areas shown on your erosion control drawings.
Real basins rarely have perfectly vertical walls, so the sloped rectangular and circular options estimate volume using frustum relationships. Bottom dimensions, depth, and a side slope ratio (H:V) generate top dimensions automatically. If survey notes already provide top and bottom areas, the custom areas method applies the same prismoidal form without re-entering lengths. For irregular footprints, break the basin into simple sections and sum exports.
Required storage is calculated from drainage area multiplied by a selected storage rate. The calculator then adds a freeboard percentage to produce a recommended target. This helps teams document whether a basin is undersized, adequate, or conservatively sized, while keeping the criterion editable for different permits or owner standards. Record the source of your rate so reviewers can validate assumptions.
A “meets recommended storage” flag is useful, but also review top width and access. Wider tops can improve stability and maintenance clearance, while steeper slopes reduce footprint. Balance excavation volume, haul routes, and dewatering practicality. Re-check after major storm events because deposited sediment reduces effective capacity. Confirm side slopes match compaction and safety requirements for equipment.
Exported CSV supports log sheets and cost tracking, while the PDF report is suitable for submittals. Keep a consistent naming convention per basin ID, date, and revision. When dimensions change in the field, rerun the calculation and store the updated export with photos and survey notes to maintain an auditable record from installation through final stabilization. This practice reduces disputes and speeds up inspection signoffs.
It reports the geometric storage volume from the selected basin shape, converted to your chosen volume unit. If you enter storage criteria, it also shows required and recommended volumes for comparison.
Use rectangular with side slopes for most excavated basins with straight embankments. Use circular with side slopes for round cells or ring berms. Enter the horizontal-to-vertical slope ratio used in the field.
Enter the rate specified by your permit, erosion control plan, or owner standard. Rates vary by region and risk profile, so treat the default suggestion as a placeholder and confirm the correct requirement.
No. Freeboard increases the recommended target only. Provided volume comes from your geometry inputs. Freeboard is a planning allowance that helps prevent overtopping and keeps functional storage available.
Keep geometry dimensions in a single length unit for accuracy. You may choose a different output volume unit, because the tool converts volumes for reporting. Use consistent area units with the storage rate.
Record the new bottom dimensions and depth after sediment removal, then rerun the calculation. Save the CSV or PDF with the basin ID, date, and cleanout notes so inspection records show restored capacity.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.