Written by: Michele Pugh, Director of the Wichita State University Environmental Finance Center

Image Courtesy of Sira Anamwong at FreeDigitalPhotos.net

They say a picture is worth a thousand words, but, did you know a picture could save you 1,000 hours, or even $1,000? Knowing what your critical assets are, and where they are located, can save you time and money when responding to problems.



First, a little about determining which assets should be considered critical to your water system. Critical assets are defined as assets that sustain your water or wastewater systems performance. Determining the criticality of assets is based on an asset having a high risk of failure, and, major consequences if it does fail. Here are five questions that will help you determine the criticality of a unique asset:

5 Questions to Help Determine Asset Criticality

  1. How old is the asset?
  2. What is the asset’s condition?
  3. What is the asset’s failure history or how is it likely to fail?
  4. What are the consequences of the failure (environmental, social, etc.)?
  5. How much would it cost to repair or replace the asset (including cost related to collateral damage such as street repairs)?

Answers to these five questions will help you determine which assets are critical. For more specific information, the Southwest Environmental Finance Center’s Reference Guide for Asset Management Inventory and Risk Analysis lists different types of assets (such as pipe, pumps, and valves) and the data that can be considered when making a criticality determination.

For example, the probability of a valve failure may be influenced by age, condition, maintenance history, clogging, and/or being subject to water hammer. The consequence of that valve failing may be backflow, pressure, maintenance, level of service or health concerns.


The above exercise will tell you what the critical assets are, but do you know where they are? Map information may help with criticality determinations and help visually convey critical locations. Some examples of this type of information include:


These are generally considered some of the most important institutions within any community. Proper operation and maintenance of hydrants, valves, and regular sewer inspections will give timely information on assets near these locations.

Federal/State/County buildings

Not all of these buildings run the same amount of risk.  Thought should be given to facilities which may impact imprisoned persons, hospitals, nursing home populations, and other persons who require significant manpower to evacuate a building if it is rendered unusable by utility failure.

Flood plains and floodways

These mapped hazard areas indicate which may be prone to flood damage, outages, and be inaccessible for longer periods of time.

Grease trap locations

This may help identify sewer lines which should be cleaned on a more frequent basis.


All water and sewer interconnections should be considered critical assets.

Force mains

Failure of force mains often have very high consequences and these assets are often not assessed in periodic sewer inspections.

Valve turn-off impact areas

We discuss this topic in our asset management workshops. While the amount of work to set up proper functionality with impact areas may be substantial, this can significantly reduce response time to main breaks by quickly identifying valves to shut off.

You can use your maps to quickly convey location information on critical assets. Marking critical assets can be done by designating them a different color on a map or adding a criticality layer to a GIS system.



Once a system has determined the criticality of their assets, an asset inventory list prioritized by criticality can inform the funding of operations and maintenance, repairs, rehabilitation, or replacement. Once the critical assets are identified and prioritized, there may be additional things to consider:

  • Does your O&M plan need to be updated to focus on critical equipment?
  • Does additional information need to be obtained for the critical equipment (things like replacement cost or other data that may be missing)?
  • Should redundancy be added?
  • Should the critical asset be relocated?
  • Should the critical asset include backup power?

Don’t forget that criticality can change over time, so critical assets should be reviewed periodically and documents updated as necessary. Taking time now to take a “criticality snapshot” of important assets can not only save you time later, but also money, and headaches.