Fire Hydrant Testing

Hydrant flow testing tests water main capabilities. Hydrant flow tests are required prior to new construction. Flow testing is also conducted prior to the installation of fire suppression systems. Static, flow, and residual pressure data are used to calculate test results which are provided both numerically and graphically.

Performed by city officials or professional contractors, fire hydrant testing verifies the performance of a city’s water distribution system, determining the pressure and rate of flow available at various locations. It measures static (non-flowing) and residual (flowing) pressure, as well as the rate of discharge in gallons per minute (GPM) of each fire hydrant.

●    Uncovering closed valves, heavy pipe-wall deposits, or other problems in a water distribution system. Reduced rates of flow often stem from blockages or other infrastructure problems.

●    Properly designing fire sprinkler systems for commercial and residential structures. If water supply pressure and flow readings are off, it can lead to an underdeveloped system that requires additional fire pumps or an expensive overhaul of pipe fitting.

Besides delivering peace of mind that hydrants will work in an emergency, hydrant flow tests enable municipalities to color-code their fire hydrants according to their strength of output.

The colors categorize hydrants by the GPM of their flow; for instance, blue hydrants have a “very good flow” of 1,500 GPM or more and red hydrants are “inadequate” with flow below 500 GPM.

This system allows fire departments to assess their water resource capabilities quickly when arriving on the scene of an emergency.

We provide the most quality Fire Hydrant flow tests in the country with the most experience and use the most up-to-date technology to ensure that pressure readings are finite. Fire Hydrants protect lives and property.

From the 2019 edition of NFPA 291

4.13.1 Public fire hydrants should be flow tested every 5 years to verify the capacity and marking of the hydrant.

The 2019 edition of NFPA 291: Recommended Practice for Fire Flow Testing and Marking of Hydrants (4.1.3) recommends that fire hydrants should maintain a residual pressure of 20 psi (pounds per square inch), or 1.4 bar, for effective firefighting, as well as to prevent backflow that could contaminate the public water supply.

Frequently Asked Questions

Annual testing and exercising of your private fire hydrant ensures it’s fully operational in an emergency, helps identify hidden damage or valve issues, and keeps you compliant with NFPA 25 and local fire codes — ultimately protecting property, lives, and liability.

There are many types of fire hydrant test including Public Fire Flow Testing, Private Annual State Fire Marshal Testing & 5-Year State Fire Marshal Testing and the cost will depend of if it involves City Scheduling or Fees. All Cities in Southern California have different rates for the encroachment permit required or Witness Fee. The City of Orange, CA offers their Fire Flow witness free of charge and cities like Rialto charge as high as $650.00 just for encroachment for fire flow testing. Please keep in mind city fees aren’t typically included in our testing cost. Fire Flow Testing cost’s between $550.00 – $975.00 depending on requirements. Annual State Fire Marshal Testing will cost between $375-$650 depending on the number of risers/hydrants at the property address. 

The cost to repair a private fire hydrant in Orange County, CA typically ranges from $1,200 to $4,500+, depending on the type of repair needed and site conditions.

Common Repair Cost Estimates:

  • Gasket or nozzle replacement: $1,200 – $2,000

  • Valve rebuild or stem replacement: $1,800 – $3,200

  • Underground leak (with excavation): $3,000 – $4,500+

  • Full barrel or hydrant body replacement: $4,000 – $6,500+

Factors That Affect the Cost:

  • Depth and type of underground piping

  • Surface access (asphalt, concrete, or landscape removal)

  • Emergency vs. scheduled repair

  • Required permits or traffic control

For an accurate quote, it’s best to schedule an on-site inspection. Hydrant Flow Inc. offers professional hydrant repair services throughout Orange County and all of Southern California.

A fire hydrant flow test is a procedure used to measure the water pressure and flow rate available from a fire hydrant. This test ensures that the hydrant can deliver enough water for firefighting operations and that the underground fire protection system is functioning properly.

A standard fire hydrant flow test includes:

  • Static Pressure – The water pressure in the system when no water is flowing.

  • Residual Pressure – The pressure remaining in the system while water is flowing.

  • Flow Rate (GPM) – The amount of water discharged, measured in gallons per minute.

  • Pitot Pressure – A pressure reading used to calculate flow rate accurately.

The process involves opening one hydrant fully while using another hydrant nearby to record pressure and flow readings. These results are used for fire system design, code compliance, and insurance documentation.

Required by:

  • NFPA 25 for annual and 5-year hydrant testing

  • California State Fire Marshal and local fire departments

  • Property managers, developers, and commercial building owners

Fire hydrant flow testing is essential for verifying the readiness of your fire protection system and ensuring public and property safety.

Annual Test:
The annual fire hydrant test is required to ensure each private fire hydrant is operational, accessible, and capable of delivering water during a fire emergency. It includes:

  • Visual inspection for damage, leaks, and obstructions

  • Flow testing with static and residual pressure readings

  • Exercising valves and lubricating operating nuts

  • Ensuring compliance with NFPA 25 and the California Fire Code

This test must be completed every year by a certified fire protection contractor.

 

5-Year Test:
The 5-year fire hydrant test is a more detailed inspection required by the California State Fire Marshal every five years. It includes all the components of the annual test, plus:

  • Internal inspection of hydrant parts and components

  • Verification of underground fire line operation

  • Additional flushing and obstruction checks

  • Documentation of long-term system condition and performance


Both the annual and 5-year tests are required under NFPA 25 and California Fire Code for all privately owned fire hydrants. These tests help ensure the reliability and safety of your fire protection system.