Four real engines — SEDCAD, IDEAL, Hydraflow, and Conveyance — with every formula rendered on screen, live USDA soil data, and treatment-train modeling that propagates across BMPs.
HydroCAD, SEDCAD4, IDEAL, and the Woolpert engines all do real engineering work. But if you're a civil engineer in 2026, you've probably hit at least one of these walls.
License tied to one machine. Nothing runs on a Mac, a tablet, or a field laptop without a VM.
Four-figure upfront cost per seat, then you pay again for the next major version.
Output tables show numbers but rarely show the substituted equation that produced them. Review takes longer than it should.
Sediment in one tool, hydrographs in another, BMP sizing in a third. Treatment trains across engines mean re-keying data.
Project files live on a shared drive. Two engineers editing the same run is a merge hazard.
K-factor and HSG still come from a PDF or a separate Web Soil Survey session. Nothing pulls it in automatically.
Every feature below is live in version 1.0.0 today. No roadmap items, no coming-soon labels.
SEDCAD (RUSLE / MUSLE, sediment basins and traps), IDEAL (15 BMP types, WQV, buildup / washoff), Hydraflow (SCS Unit Hydrograph, Modified Puls routing), and Conveyance (14 cross-section types, Manning's, HGL). Each engine implements the published equations directly.
Results display the KaTeX-rendered equation, the substitution with your inputs, and the computed value. No black boxes. If a reviewer asks where a number came from, you can point at the screen.
Click a button, draw a polygon, get real SSURGO data for your site: hydrologic soil group, sand / silt / clay fractions, K-factor, organic matter. The values feed directly into RUSLE and SEDCAD trap efficiency calculations.
Chain BMPs on the diagram and watch pollutant reduction, peak flow, and sediment yield propagate through the system. Sequential removal uses Etotal = 1 − (1−E1)(1−E2)…(1−En).
Works on any modern browser, desktop or tablet. Projects sync to per-user Supabase storage so you can pick up a run from a different machine. Version 1.0.0 is live now.
Trial users get a watermarked PDF marked TRIAL · NOT FOR REGULATORY SUBMITTAL. Subscribers get clean reports stamped with engineer-of-record info, ready for sealing per your state's PE rules.
14-day free trial on every plan. No credit card required to start. Cancel anytime through the Stripe customer portal.
HydroComplete runs in a browser on any platform, renders every formula on screen, chains BMPs across engines in a single project, and stores projects in the cloud. It is not a drop-in HydroCAD replacement for detention routing workflows specifically — HydroCAD has decades of refinement there. HydroComplete does implement Modified Puls reservoir routing through its Hydraflow engine, which covers most detention-pond analyses.
The engines use published, peer-reviewed equations: RUSLE from USDA ARS, MUSLE from Williams (1975), SCS Unit Hydrograph from NRCS TR-55, Modified Puls routing from USACE / HEC-22, Manning's equation from Chow (1959).
Every result is shown with its formula, the substitution using your inputs, and the computed value — so you (or your reviewer) can verify each step by hand if you want to.
The SEDCAD engine implements the same RUSLE / MUSLE soil loss methods and the same trap efficiency calculations as SEDCAD4. The IDEAL engine implements 15 BMP types with water-quality-volume sizing and buildup / washoff pollutant loading.
Honest answer: the original desktop apps are still authoritative for some specialized workflows, and we don't pretend otherwise. HydroComplete is designed to cover the core day-to-day use cases with better transparency, better integration across engines, and a modern interface.
Trial reports are watermarked "TRIAL · NOT FOR REGULATORY SUBMITTAL" on every page. Subscriber reports are clean and include the engineer-of-record information you enter in project settings. Applying the PE seal is the user's responsibility under the rules of the state where the work is performed — HydroComplete generates the deliverable, you stamp it.
The editor loads in your browser, but calculations run on our server through an authenticated API so the engines stay consistent across users and versions. There is no offline mode right now. You need an internet connection to compute.
Through the Stripe customer portal, any time, in about three clicks. There is no contract, no cancellation fee, and no "call us to cancel" routine.