Stormwater drainage design, done right.
HydroPrep is the modern drainage network calculator for civil engineers. Draw your catchment network, enter your data, and get accurate peak flow results in seconds — no spreadsheets, no manual lookups.
Analysis Results
Peak Flow
0.87 m³/s
Total Area
4.2 ha
Runoff Coeff.
0.68
Time of Conc.
18 min
ARI
1-in-100yr
✓ All checks passed
Compliant with AS/NZS
Features
Everything you need for drainage design
Visual network builder
Drag and drop subcatchments, junctions, detention ponds, and outfalls onto a connected canvas. See your entire drainage system at a glance.
Rational method calculations
Accurate peak flow calculations using the Rational Method, with ARI-based IFD intensity lookup and automatic time of concentration derivation.
Detention pond routing
Model detention basins with level-storage-discharge curves. Automatically verify that outflow meets downstream constraints for your design ARI.
One-click report export
Generate a professional, print-ready PDF summary of your entire network — inputs, calculations, results, and compliance checks — in seconds.
How it works
From blank canvas to certified report
Draw your network
Place subcatchments, junctions, ponds, and outfalls on the canvas. Connect them with edges to define flow paths.
Enter catchment data
Set areas, runoff coefficients, pipe lengths, and design storm parameters. HydroPrep handles the rest.
Get certified results
Run the analysis in one click. Review peak flows, compliance checks, and export a professional report.
Ready to design smarter?
Join engineers who have traded spreadsheets for HydroPrep. Free to start, no credit card required.
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