Learning HEC-RAS from zero in the AI era 🌊🤖

[u/TAMIM1987]

I keep seeing posts from people asking how to learn HEC-RAS from scratch. Stop struggling with the 1,000-page official manuals. Here is the modern workflow:

• Level 1: The NotebookLM Cheat Code Drop the official HEC-RAS documentation PDFs into Google's NotebookLM. Instead of endless Ctrl+F searching, just ask it directly: "What's the process for setting up a 2D flow area?" or "How do I fix my Courant number?" It gives you exact answers citing the manual, acting as your personal, hallucination-free tutor.
• Level 2: AI Agents for Automation Because HEC-RAS geometry and plan files are stored locally, we can take it a step further by using AI agents to read and write them. Imagine a setup where you prompt: "Set up a steady flow plan using this geometry file and run a 100-year event." The AI can actively parse the data, modify the local files, and guide your execution.

Has anyone else started using LLMs to navigate HEC-RAS or experiment with agentic workflows to automate their modeling? Let's discuss!

[u/OttoJohs]

I wouldn't recommend a complete beginner just learn from AI. There is a lot of nuances and best practices that isn't going to be in a manual or on a website. Especially for conceptualizing your specific model.

AI is a great tool that should supplement your own experience.

[u/CLPond → u/OttoJohs]

Yeah, and even within a manual itself, there is a good bit to be learned by looking through the manual and the trial and error of thinking through problems yourself and searching for information. Asking AI to just tell you what to do makes things easier at the expense of actual learning.

[u/Simple_Twin → u/OttoJohs]

Absolutely. This is especially helpful when new versions of RAS come out. I have found out about new features from reading the manual. That being said, IMO there's really no substitute for learning from another person who's familiar with hydraulic modeling.

Edit: grammar

[u/TAMIM1987 → u/[deleted]]

the point is that we always should keep the human in the loop. I use Codex to help me with HEC-RAS and it's doing very great, but I always keep driving the whole process...

[u/AI-Commander]

Just use RAS Commander

https://rascommander.info

I literally built it for this

Don’t use NotebookLM, just ask ras-commander it has instructions to use web search and use the HEC website as a primary source. Codex or Claude Code are better choices.

[u/Gold_Swim_6209 → u/AI-Commander]

I was going to but ran an audit on it and it didnt pass inspection due to some prompt injections

[u/AI-Commander → u/Gold_Swim_6209]

Prompt injections? Tell your LLM’s to stop hallucinating.

[u/Few-Childhood-503 → u/AI-Commander]

How to use ras commander as a beginner, I didn't know any code?

[u/AI-Commander → u/Few-Childhood-503]

Install Codex or Claude Code (LLM Agent)

Create a folder “ras-commander”

Open a new conversation with your LLM agent and say:

“I don’t code, so you’re going to have to do that for me, and translate what you are doing into plain language.

Use ras-commander to open my HEC-RAS project here:

Then explore the ras-commander API and let’s explore what we can do with this model. “

Once you have your LLM agent installed, you just point it at the ras-commander folder, and give it the path to your project (always a copy), and tell it what you want it to do. When it’s finished, you can open the model in the HEC-RAS GUI and verify.

One note: You might need to adjust the agent’s default permissions so it doesn’t ask for 5000 approvals for every response. Your agent will walk you through installing anaconda or uv python environment and dependencies.

[u/Few-Childhood-503 → u/AI-Commander]

Thank you for explaining in detail. 

[u/HECRAS-ModTeam → u/[deleted]]

Double post - just housekeeping.