A water distribution system does not always supply the required or normal demand to customers under all conditions. It is important for water companies to be informed to what degree or level that a water system is able to supply its customers when an emergency or calamity scenario occurs. A calamity event can be one or more than one element out of service. When such an event occurs, it is expected that the service can only be maintained to a certain level before the outage is fully recovered.

In order to deal with a recoverable calamity, the concept of water supply is introduced to quantify the supply capacity of a water distribution system. It is defined as a percentage of the supplied demand over the normal demand. Water companies are required to comply the minimum water supply level under a calamity of one element outage, which is expected to be fully repaired within 24 hours. The modeling approach for evaluating water supply level for the use cases as follows.

Use Cases