NFPA Standard Explorer

Recommended practice for hydrant flow testing and marking to indicate available fire service water supply. Commonly referenced for preplans, first-due water supply decisions, and coordination with water utilities (high level).

Hydrants are not all equal. Without current flow information, crews can over-commit to a weak water source, delay attack decisions, and lose time switching supply strategies during critical minutes.

• Hydrant flow testing procedure concepts (high level)
• Marking/identification concepts to indicate available supply
• Data collection and documentation concepts
• Coordination concepts with water authorities and system changes
• Seasonal/maintenance and impairment awareness concepts
• Using flow data in pre-incident planning and tactical decisioning (high level)

• Building a first-due hydrant plan with primary/secondary options
• Scheduling hydrant flow tests by district and keeping records current
• Improving map notes for weak mains or dead-end streets
• Training pump operators to interpret flow test results operationally

• A hydrant location equals a reliable supply (flow can vary widely).
• Old flow data is ‘good enough’ (system changes and seasons matter).
• Marking is cosmetic (it’s a fast decision aid under stress).

• Flow test high-risk occupancies and long dead-ends first
• Store results in a simple map layer (date + flow note + residual pressure note)
• Add ‘backup hydrant’ notes for every primary hydrant in the district
• Coordinate retests after water main work or repeated low-flow findings