HEC-RAS 7.0.2: What Changed Since 6.7 Beta??
Tthe last time I updated yall RAS was on 6.7 BETA and we have seen a major version jump inot the 7's with some serious new features.
HEC-RAS 7.0.2 arrived in October 2026, following the official 7.0 release earlier this year. If you read my previous post on 6.7 Beta 5, version 7.0 is the official release of that development effort. Version 7.0.2 brings another round of fixes.
The full release notes are here, and you can download HEC-RAS here. Let’s start with the bridge modeling.
2D Bridges—Pressure Flow and Overtopping
One of the most interesting developments carried forward from the 6.7 betas is the 2D Bridge with Pressure/Overtopping method.
This allows separate 2D calculations for:
Flow beneath the bridge during open-channel conditions.
Pressurized flow when water reaches the underside of the deck.
Flow over the deck when the bridge overtops.
RAS creates a second layer of computational cells above the bridge deck to handle overtopping while retaining the cells below for flow through the opening. The Corps explains the method and setup here.
A quick clarification: pressure flow itself is not new to RAS. The 1D Family of Rating Curves approach already brings 1D bridge hydraulics into a 2D model, including the familiar energy or pressure/weir high-flow calculations. The newer method resolves the bridge flow using the detailed two-layer 2D approach. The Corps has a comparison of the bridge modeling options here.
The setup takes some attention:
Piers and abutments need to be represented in the terrain.
The mesh should align with the bridge deck edges.
Deck geometry and minor-loss parameters still matter.
There is also a walkthrough with screenshots on RASHMS.com if you want another look at the workflow.
My Experience—and a Relevant 7.0.2 Fix
I tried using the Pressure/Overtopping method on a bridge in 7.0.1, but kept encountering errors that I could not get resolved. I ultimately moved away from that method, even though I felt the bridge was experiencing pressure flow. That was frustrating, because this is exactly the type of situation where I wanted to use it.
There is some encouraging news: 7.0.2 lists a fix for models combining Pressure/Overtopping bridges with infiltration. That combination could fail with an HDF error referencing READ_UN_HYDROLOGY. See the resolved issues here.
I have not confirmed whether that was the error affecting my project, but it gives me a specific item to check when revisiting the model. Hopefully, this makes the next attempt smoother.
Bridge Scour Export Fixes
The scour tools I highlighted previously also received attention. Version 7.0.2 lists corrections for:
Exporting the contraction-section water-surface elevation instead of the approach-section elevation.
SI-unit exports being interpreted as US Customary in Hydraulic Toolbox.
The default contraction reference line for abutment Scour Condition A.
These are worth reviewing if you use the RAS-to-Hydraulic Toolbox workflow. An automated export saves time, but I still want to know exactly which section and hydraulic values it is sending over. Scour export corrections.
Pipe Networks and Other Fixes
Version 7.0 removed the Beta tag from pipe networks and introduced additional loss calculations and inlet stability improvements. Details are here.
The 7.0.2 fixes include metric inlet calculations, a crash involving pipe-network and hydraulic-structure gates, large-model memory problems, and merged-terrain priority. Each version the piped networks input, results, and general workflow seem to improve, so this is becoming more and more promising and I am now fully utilizing this feature on smaller scale project that I need to account for subsurface stormwater networks.
Coordinated Results Plots
Version 7.0 also added a Coordinated Plot, bringing profiles, time series, rating curves, and hydraulic property tables into one results view.
The useful part is the connection to the map: selecting a computational location highlights it on the map, and you can select locations from the map to inspect their results. Pan, zoom, and animation work across the views.
When you are tracking down something strange near a bridge or connection, being able to see both the location and its hydraulic results together should save some clicking. Check out the Results Output Plots section here.
Full 7.0.2 fix list is linked here. Those are the items that caught my attention. The detailed bridge pressure-flow method remains high on my list to revisit. Back up your project, compare results when changing versions, and get out there and model some flood risk!
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