What is it?
Fixing vulnerable water mains or sewer pipes may require more than available resources (time or fund). In such cases, asset managers handle the situation in two ways:
- Look for more knowledge to better assess the network through computational or physical assessments
- Identify the consequence of failure on each segment
The computational assessments are useful to pinpoint problematic parts of the network, although prioritization among the selected pipes still requires further information.
The consequence of failure or the criticality score on each segment of the pipe is the accepted best practice to make this distinction.
How to Calculate it?
If a break happens on a pipe that delivers water to five premises, it has a much lower impact comparing with a pipe that distributes water to five hundred premises.
In the above example, the number of premises connected to pipes can be considered as a valid measure, although a better approach might be the total demand. i.e. one connection might be a connection to a high rise with 800 units.
Sometimes even the demand becomes a secondary concern when the water supply is for critical services such as hospitals or other key buildings. The proximity to major roads or environmental concerns as a consequence of failure might be other examples of such preferences. Selecting the weights can be a combination of multiple factors and each city's priorities might be different.
Pan & Zoom in the map below which demonstrates criticality score for the water network in the City of Kitchener, ON.
The Criticality is identified using the length of the connected segments(Property of Waterlix Inc.)