topic Re: Looking for Simple GIS-Based Tools for Unidirectional Flushing (UDF) Planning in ArcGIS Online Questions

Looking for Simple GIS-Based Tools for Unidirectional Flushing (UDF) Planning

KhemAryal — Fri, 09 Jan 2026 19:48:32 GMT

Does anyone know of any GIS tools or methods for planning unidirectional flushing (UDF) for an entire water distribution system?

For those unfamiliar, UDF is a proactive maintenance technique used to improve water quality and system performance. It involves flushing water mains in a controlled, sequential manner to remove sediment, biofilm, and stagnant water, which helps maintain chlorine residuals and reduce customer complaints about taste, odor, or discoloration.

I’m particularly interested in simple solutions that integrate with GIS, rather than complex hydraulic modeling software. Ideally, the tool should:

Identify which hydrants to flush
Determine which valves to close
Organize the flushing process in chronological order so no water main is left unflushed
Use GIS mapping for visualization and planning

Are there any tools, workflows, or best practices that combine GIS with UDF planning in a straightforward way? Any recommendations or experiences would be greatly appreciated!

Re: Looking for Simple GIS-Based Tools for Unidirectional Flushing (UDF) Planning

VenkataKondepati — Fri, 09 Jan 2026 22:09:13 GMT

Hi @KhemAryal,

Based on what I understand, there isn't a direct GIS tool that can completely plan UDF without using hydraulics. However, lots of utilities use GIS network tracing with simple sequencing to deal with this problem. You can plan and visualize in GIS through valve isolation traces, to specifically define flushing zones. Then, you can order hydrants from dead ends towards supply, which will help you avoid having to completely model. If you want something more automated, I'm sure most solutions eventually have to use lightweight hydraulic
logic.

Please refer below documents but not a full solution.
https://www.pnws-awwa.org/wp-content/uploads/2023/06/Distribution-System-Flushing.pdf

https://www.epa.gov/system/files/documents/2022-04/ds-toolbox-fact-sheets_flushing_final-508.pdf

Re: Looking for Simple GIS-Based Tools for Unidirectional Flushing (UDF) Planning

KhemAryal — Mon, 12 Jan 2026 16:03:42 GMT

Thank you @VenkataKondepati

We are moving to Utilities Network soon and hopefully that would provide some possibilities.