Delta Hydro Studio
FreemiumVerified
Browser-based hydrology and hydraulics calculators for practising engineers — no install, report-ready output.
FHWA Hydraulic Toolbox
StableA free bundle of FHWA drainage calculators: channels, weirs, curb & gutter, riprap, detention and more.
by US FHWA
- Pricing
- Gov-Public
- License
- US Government (public domain)
- Commercial use
- Permitted
- Ecosystem
- Standalone
- Platform
- Windows
About FHWA Hydraulic Toolbox
The Hydraulic Toolbox collects the everyday calculators of highway drainage design into one free FHWA program: open-channel normal/critical depth, weir and orifice flow, curb-and-gutter and inlet spread, riprap sizing, rational-method peaks and simple detention routing — each following the relevant FHWA circular (HEC-22, HEC-15 and friends).
It will not replace a network model, but for the dozens of small calculations in any roadway or site drainage package it provides agency-recognised methods with printable output. Pairs naturally with HY-8 for crossings.
Where it fits in the workflow
TerrainCatchmentRainfallRunoffRoutingHydraulicsMappingReporting
Appears in collections
- The Free Drainage Engineer's Toolkit
Zero-budget, reviewer-accepted tools for everyday stormwater and drainage design.
Alternatives to FHWA Hydraulic Toolbox
Ranked by the topics, categories and workflow stages they share with FHWA Hydraulic Toolbox.
Causeway Flow
Commercial
Storm and foul water drainage design and 1D hydraulic modelling software for UK and Irish civil engineers.
HEC-RAS
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The world's most used hydraulic model: free 1D/2D river analysis, sediment, water quality and flood mapping.
HydroCAD
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The US land-development standard for TR-55/TR-20 hydrographs and detention pond design.
HY-8
Gov-PublicVerified
FHWA's free culvert analysis program — the reference implementation of HDS-5 culvert hydraulics.
LocalSWMM
Open Source
Browser-based urban stormwater and drainage modeling powered by OpenSWMM 6 compiled to WebAssembly.