: Import or input the exact Intensity-Duration-Frequency (IDF) curves or NOAA Atlas 14 data required by your local jurisdiction.
: Generation of single hydrographs for site analysis. Design Tools :
Once installed, launching the extension is straightforward. Remember: before you can start any Hydraflow extension. After the extension launches, you can close Civil 3D if you wish. Remember: before you can start any Hydraflow extension
The Hydraflow Express Extension is typically with AutoCAD Civil 3D. If it is missing, you can acquire it through these methods: Useres Guide - Autodesk
A: Yes. The extension has been included as an installation option since at least Civil 3D 2008 and is carried forward through current versions. For more modern versions, especially if you use Civil 3D 2025 or 2026, the option remains, though the method to launch it may vary slightly. If it is missing, you can acquire it
However, “extra quality” downloads come from verified legacy sources. Here are the three tiers of legitimacy:
Solves normal depth operations and creates rating curves for trapezoidal, rectangular, triangular, and user-defined channel segments. and Modified Rational methods.
If you upgraded from an older Windows version, you may need to reinstall the legacy Hydraflow dependencies. Autodesk no longer supports very old versions (e.g., 19‑year‑old releases), so ensure you are using a recent, supported Civil 3D release.
Go to the "All Products and Services" section.
Users can compute runoff hydrographs using SCS, Rational, and Modified Rational methods. It also helps estimate required detention storage for pond sizing.
: Dedicated sizing tools for these hydraulic structures. Hydrology Modeling :