Stormwater analysis, driven straight from your Civil 3D drawing.

Stop re-typing catchment areas, pipe runs and invert elevations into a separate model. The HydroComplete connector reads your Civil 3D pipe networks, catchments and surfaces, runs the analysis, and writes results back into the drawing — with every formula shown and a sealable PDF at the end.

Join the early-access list Try the web app first

Built by a practicing PE. Standard public-domain methods — Rational, SCS/NRCS, Manning, HEC-22. No black boxes.

The re-entry tax

Your model already lives in Civil 3D. Your analysis shouldn't start from scratch.

Today

Export, re-key, or hand-trace pipe networks into a separate hydraulics tool
Areas and Tc transcribed by hand — a transposition error away from a wrong design
Results stranded in another app; back-annotating the drawing is manual
Black-box numbers you can't defend line-by-line to a reviewer

With the connector

Catchments, pipes and surfaces read directly from the open drawing
Areas, slopes and lengths come from the model geometry — no transcription
Design-capacity overload flags, HGL labels, and a 3D profile polyline written back on the drawing
Every step shows its equation and inputs; export a sealable PDF report (Pro)

How it works

Three steps, inside the software you already use.

Select in the drawing

From the HydroComplete ribbon, pick the pipe network and catchment objects you want to analyze. Geometry and connectivity come straight from Civil 3D.

Run the engines

Rational peak flows routed per catchment through the pipe network, live NOAA Atlas 14 IDF from your drawing location, Manning capacity and overload checks, and a normal-depth HGL pass with optional HEC-22 losses — computed on HydroComplete's audited engines.

Annotate & report

Label overloaded pipes and HGL elevations, draw a 3D HGL profile polyline on HC-HGL-PROFILE, and export a formula-transparent PDF you can put your seal on — activate Pro with HC_ACTIVATE; HTML reports stay free.

What it covers

The everyday hydrology & hydraulics, done in place.

Rational method SCS / NRCS curve number Time of concentration Live NOAA Atlas 14 IDF Normal-depth HGL (HEC-22) HGL profile polyline Per-catchment Q routing HC_CAPACITY overload check Manning capacity & partial flow HC_ACTIVATE Pro licensing PDF Pro export Detention / routing USDA soils lookup

New in v0.5

See the HGL on the drawing, route real catchment flows, unlock Pro.

v0.5 closes the loop between analysis and the plan — profile geometry in the drawing, design Q that follows your catchments through the network, and a clear path to sealable PDF export.

HGL profile polyline

After HC_HGL writes midpoint labels on HC-HGL, draw a Polyline3d per pipe network on layer HC-HGL-PROFILE — vertices at each pipe's upstream and downstream plan XY with Z set to the computed HGL. Yes/No prompt, default Yes.

Per-catchment Q routing

When catchments exist, HC_CAPACITY and HC_HGL prompt Route catchment flows (default Yes). Each catchment's Rational peak routes through pipe-network topology so design Q varies by reach — outlet structure, nearest structure, or name match.

HC_ACTIVATE Pro licensing

Run HC_ACTIVATE with your work email and beta token (hc_live_*). Online validation against hydrocomplete.com, with offline stub fallback. HC_LICENSE shows Free/Pro status; HC_REPORT_PDF unlocks after activation — HTML reports stay free.

Why this, not the bundled tool

Built for the part SSA makes painful.

Civil 3D ships Storm and Sanitary Analysis, and it's capable. The connector isn't trying to replace a full hydraulic-modeling suite — it's for the routine sizing and reporting you do constantly, where the friction is transcription and defensibility.

	Bundled SSA workflow	HydroComplete connector
Reads geometry from the drawing	Import / re-map	Direct from objects
Shows the equation behind every number	No	Yes — line by line
Sealable PDF report with inputs & sources	Limited	Built in
State-specific IDF / soils baked in	Manual	Live NOAA PFDS + USDA lookups
Design-capacity overload flags in the drawing	Separate review	HC_CAPACITY + labels
HGL profile polyline written to the drawing	Manual trace	HC-HGL-PROFILE
Per-catchment design Q through the network	Uniform or hand-built	Routed Rational peaks
Pro PDF activation in-product	Separate account	HC_ACTIVATE
Learning curve for a quick sizing	Steep	Ribbon → result

Civil 3D, AutoCAD, and Storm and Sanitary Analysis are trademarks of Autodesk, Inc. HydroComplete is an independent product and is not affiliated with or endorsed by Autodesk.