I'm seeing zero or N/A for water quality results (trace, age or constituent)

  Product(s): Bentley WaterGEMS, WaterCAD
  Version(s): 08.11.XX.XX
  Environment: N\A
  Area: Calculations

Problem

After setting up a trace, age or constituent analysis, I'm not seeing any calculated trace, age or constituent results. 

Solution

1) Confirm that the Calculation Type in the calculation options is set appropriately. If it's set to "hydraulic only", water quality results will not be computed.

2) Make sure the model is successfully computing. If you see red messages in the User Notification window after computing the model, there may be issues preventing the model from computing, which will need to be addressed first.

3) When viewing the water quality results, ensure that you're either looking at the maximum or minimum, or a graph. If you're only looking at the "Trace (Calculated)", "Age (Calculated)" or "Concentration (Calculated)" field for an element directly after computing a model, that will be showing you the result at time zero.

Either use the Time Browser and step through time to see the calculated result change, or right click the element(s), choose Graph and select the water quality result in question.

4) Ensure that the respective alternative has been set up correctly, or for Age, make sure there is a source of fresh water.

For an age analysis, the calculated age represents how long the water at that element has been in the system. In a model where there is no source of "fresh" water (a reservoir), the age of the water on all nodes will be the same. However, by adding a reservoir to the system, age will start to vary on different nodes.

  • For a Constituent analysis, make sure the constituent alternative is set up correctly with the right constituent, make sure that alternative is assigned to the right scenario, and make sure the constituent itself is set up correctly. Confirm the correct units and values entered.
  • For a Trace analysis, make sure the trace alternative is set up with the correct 
  • For an Age analysis, ensure that there is a source of fresh water. With Age, the calculated age represents how long the water at that element has been in the system. In a model where there is no source of "fresh" water (a reservoir), the age of the water on all nodes will be the same. However, by adding a reservoir to the system, age will start to vary on different nodes.

Note: if you need to analyze multiple trace sources or multiple constituents, use the Water Quality Batch Run feature.

See Also

How can I troubleshoot my model when my water age results don't appear correct?

Water age results in a pipe are different than the age in a downstream junction

Age (Calculated) vs. Age (Minimum) vs. Age (Maximum)

Is WaterGEMS capable of modeling the formation of constituents in networks?

The concentration at the stop node directly after a constituent source in a tank is decreasing rapidly

How to find volume of water coming from a trace element?

Analyzing concentration of multiple constituents, or a multi-point trace

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