topic Can one web map hold two separate utility networks (water + sewer)? in Water Utilities Questions

Can one web map hold two separate utility networks (water + sewer)?

MatteoMagnani_WT — Thu, 30 Jul 2026 10:13:33 GMT

Hi everyone,
I have two Utility Networks, one for water, one for sewer. They're completely independent: each one lives in its own enterprise geodatabase and is published as its own web feature layer on the same federated server. What I'm trying to build is a single web map that shows both networks together, plus a few shared reference layers. Every time I share that web map it fails at the very end with Failed to add web item.

What convinced me that the issue it's the two-networks combo and not something else is this:

Water UN only (sewer removed): publishes fine.
Sewer UN only (water removed): publishes fine.
Both in the same map: always fails.

So, a few questions:

Is it a real limitation that a web map can only reference one utility network at a time?
If it is, is there anything official that states it, so I can point to it?
What's the recommended way to give users a single, unified view over both networks — two separate web maps combined at the app level?

Environment: ArcGIS Pro 3.7, ArcGIS Enterprise 11.5.0, Utility Network version 7.

Thanks in advance.

Re: Can one web map hold two separate utility networks (water + sewer)?

RobertKrisher — Thu, 30 Jul 2026 13:44:48 GMT

I was able to add two utility networks to a map in ArcGIS Po and share that as a web map to my portal without receiving an error.

Can you share your workflow? There may be something else going on. Also, if you haven't already, please consider logging a case with support.

Re: Can one web map hold two separate utility networks (water + sewer)?

MatteoMagnani_WT — Thu, 30 Jul 2026 13:58:46 GMT

Thanks Robert,

I published each Utility Network following the standard Esri publishing workflow for UN web feature layers, one for water, one for sewer, each from its own enterprise geodatabase, each as its own web feature layer on the same federated server. Both published cleanly on their own.
For the combined map, I took the water and sewer maps (with the color symbology) from the Esri Water/Sewer Utility Network solutions and brought them together into a single map in ArcGIS Pro.
After combining the maps, I repointed the layers to the already-published web feature layers, and I also added the layers of the two Utility Networks themselves to the map.
At that point sharing the combined web map fails at the very end with "Failed to add web item."

As noted, water-only and sewer-only both share fine; only the combined map fails.

Re: Can one web map hold two separate utility networks (water + sewer)?

MatteoMagnani_WT — Thu, 30 Jul 2026 14:36:20 GMT

It turned out the problem was NOT related to having two utility networks in a single map. The share was probably failing because the combined web map exceeded the maximum POST size accepted by our portal on upload. The CIM was created and converted to JSON correctly, but the final "Uploading the web item" step failed with the message "Failed to add web item."

I tried publishing the web map with both networks while removing, as a test, the water devices — and it worked.

Re: Can one web map hold two separate utility networks (water + sewer)?

RobertKrisher — Thu, 30 Jul 2026 17:51:53 GMT

@MatteoMagnani_WT good to hear you figured out what the problem was. One of the things I've seen some other customers do to help with this problem is to ensure they are removing layers/symbology/configuration that they don't need from the map.

This is especially relevant if you implemented the expanded versions of both of these models and didn't remove any of the unused asset groups/fields. Each subtype layer (asset group) contains a definition for each field (name, alias, visibility, etc) so the definition can become quite large when you include these definitions from one very large data model or two moderately complex data models.

This is currently a known issue with Portal. If you log a case with support you can get yourself added to the enhancement request: ENH-000175387: Add support for changing the maximum size in bytes for POST requests sent to Portal for ArcGIS through the addition of a maxHttpPostSizeInBytes property in the ArcGIS Portal Administrator API.

There is a workaround for the issue that the support analyst should be able to walk you through.