Export Water Flow Rate from Flood Simulation

[Fabian_Schroeer]

Hi, is there a way to export the water flow rate (m^3/s) from a flood simulation? Currently, it seems that only “water depth,” “water absolute height,” “water velocity vector” as U-V, and “water speed” can be exported. Strangely, there is no option to export the water flow rate.

Or am I missing something?

(I know that I can calculate the flow rate myself based on the water depth and water velocity. But it would be much easier if you could export it directly)

[MiguelParedes · Accepted solution]

@Fabian_Schroeer 
Greetings Fabian,

No, you have not missed anything. According to the documentation, ArcGIS Pro currently does not allow exporting water flow rate (m³/s) from a flood simulation.

While ArcGIS Pro’s flood simulation can display water flow rate in the 3D scene, it still does not provide an export function for that property.

The official ArcGIS Pro documentation states that the simulation layer’s symbology can visualise:

• Water flow rate (m³/s)
• Water depth (m)
• Water speed (m/s)

but this is specifically for colorizing the display, not exporting rasters or data layers. 

As you mentioned, one can compute flow rate manually using the formula:
Flow Rate (m³/s) = Velocity (m/s) × Cross‑sectional area (m²)

ArcGIS Pro exports:

• Water depth raster
• Water velocity (U–V vectors) raster

These provide everything needed to compute flow rate afterward (in Raster Calculator, Python, or external GIS/hydrology tools).

ArcGIS Pro’s flood simulation engine is designed for rapid, GPU‑based shallow water modelling, intended mainly for visual exploration, not full hydraulic engineering outputs.

The technical paper and documentation emphasize that many advanced hydraulic outputs are not included by design—this tool is not intended to replace tools like HEC‑RAS or Arc Hydro for detailed flow modelling.

I hope the above is of assistance.

Muchos saludos,

[Fabian_Schroeer]

Hi Miguel,

thanks for your reply!

We had now written a Python script that we used to calculate the flow rate in m^3/s from various time steps. The results are actually very similar to those from HEC-RAS.

As you already mentioned, the simulations are GPU-based. We currently have an NVIDIA A16-16Q, but unfortunately the simulations are very slow and run at 100% capacity throughout the simulation. Do you have any recommendations as to which GPUs are best suited for this? Or which ones do you use for your tests?

Best regards,
Fabian