Hydrant Flow Testing
What Is a Hydrant Flow Test?
A hydrant flow test (also called fire flow testing) involves flowing water from one or more hydrants while recording:
Static pressure (pressure in the water system before opening the hydrant)
Residual pressure (pressure remaining while flow is occurring)
Flow rate / discharge from one or more flowing hydrants using a pitot gauge
Pressure drop analysis, hydraulic calculations, and available fire flow at target residual pressure
From these measurements, we can determine whether the water distribution system around the hydrant is adequate for firefighting demands or fire protection system design. The test often follows NFPA 291 – Recommended Practice for Fire Flow Testing and Marking of Hydrants. Fire Underwriters+3LHS Inc.+3WSRB+3
Hydrant testing often requires permits and coordination with municipal water departments (since the hydrant valves are typically operated by city staff). For example, in Toronto, flow tests are only permitted (weather-dependent) between April 1 and November 15, with the city controlling hydrant turn-on/turn-off. City of Toronto
When & How Often Are These Tests Required?
While local municipalities may set specific schedules, standard practices and guidance suggest:
| Type | Recommended Interval / Trigger | Notes |
|---|---|---|
Public hydrants (municipal system) | Every 5 years (for full flow tests) | NFPA 291 recommends public hydrants be flow tested every 5 years Fire Underwriters+3H T O+3LHS Inc.+3 |
| Annual inspection / flushing | At least once per year | Hydrants should be flushed annually to clear debris and verify operability H T O+2Ontario Fire Protection+2 |
| Private hydrants | May require more frequent testing (e.g. annually) per local code or insurance | Private systems often have stricter requirements in fire-suppression contexts H T O |
| After major changes / construction | Immediately following alterations to water mains, additions, system upgrades | To verify system capacity under new conditions |
| On permit or design requirements | During new building design, sprinkler design, or fire protection system submission | Hydrant data is often required for hydraulic calculations in sprinkler or standpipe system design |
In many Ontario jurisdictions, hydrant flow tests are offered (or permitted) only in warmer, non-freezing months (e.g. April to November). For example, in the Region of Durham, flow tests are scheduled between April 15 and November 15 (weather permitting). Durham
Why Hydrant Flow Testing Is Important
Fire Protection System Design
Hydrant test data is central to determining whether your site’s water supply can support sprinkler, standpipe, or suppression system demands. Inaccurate or missing flow data leads to over-design, underperformance, or permit refusal.
Municipal & Community Safety Assurance
Municipal water and fire departments use hydrant flow results to assess water main adequacy, detect bottlenecks, plan upgrades, and ensure fire coverage across districts. Fire Underwriters+2Velocity Water Services+2
Insurance & Liability Considerations
Insurance underwriters often require documented flow test results to validate that hydrants can deliver sufficient fire water. Without them, claims may be denied or premiums raised.
Identifying System Deficiencies
Tests can reveal low residual pressure, water main constrictions, closed or obstructed valves, internal corrosion, or undersized piping — issues that must be addressed before a fire event.
Regulatory & Code Compliance
While not every Ontario jurisdiction mandates hydrant flow testing in the Fire Code explicitly, regulatory frameworks often use flow data in fire protection reviews, and many municipal bylaws govern hydrant operation. In Ontario’s Fire Code (O. Reg. 213/07), hydrants are required to be colour-coded per NFPA 291 marking standards. Ontario
Operational Readiness & Maintenance
Regular testing and inspection maintain hydrants in reliable condition, preventing surprises during emergencies. Ontario Fire Protection+1National Life Safety Group Canada+2Ontario+2
Our Hydrant Flow Testing Service
01
Permit & Coordination
We identify the required municipal permits and liaise with the water or public works department to schedule hydrant operation. In many cities, the hydrants must be turned on/off by municipal staff.
02
Pre-test Inspection & Site Preparation
We inspect hydrants visually for damage, obstructions, leaks, paint buildup, or corrosion. We verify the condition of the isolation valve (if present). We also plan safe water discharge paths and public safety barriers.
03
Conducting the Flow Test (per NFPA 291)
We measure static and residual pressures, open the hydrants to record flow rates, and calculate the available fire flow. All readings follow NFPA 291 standards to ensure accuracy and compliance.
04
Data Analysis & Reporting
We prepare a detailed report, including static/residual pressures, calculated flow curves, deficiency analysis, and recommendations (e.g. required improvements, alternate hydrants, main upgrades).
05
Follow-up Consultation
We review findings with you: if deficiencies exist, propose mitigation strategies, coordinate with water departments or civil engineers, or advise on alternate fire protection design approaches.
06
Recordkeeping & Documentation
All test data, permit records, and reports are archived for your reference, engineering submissions, or municipal inspections.