Hydrant numbers are stamped on the top of each fire hydrant nut. Using this number is the best way to communicate. Fire flow tests are conducted by flowing one hydrant and reading the residual pressure at another, non-flowing hydrant. The non-flowing hydrant will be at the location specified. In some cases a fire flow is not feasible or useful. Such cases may include:

• Areas that do not contain 2 hydrants closely connected hydraulically
• Areas where property damage from a flowing hydrant is likely
• Hydrants under the influence of pressure reducing valves
• Hydrants on large transmission mains

Waterworks will, at their discretion, substitute results from a calibrated hydraulic model when a flow test is not feasible. If model results are used, it will be noted on the report sent to the customer. Flows are scheduled through the Distribution Operations Branch and are usually completed within 10 business days from date of receipt, unless unforeseen events adversely affect scheduling.