404.5 Adequate Water Supply
Adequate water supply shall be determined for purposes of initial attack and flame front control as follows:
One- and two-family dwellings. The required water supply for one- and two-family dwellings having a fire flow calculation area that does not exceed 3,600 square feet (334 m2) shall be 1,000 gallons per minute (63.1 L/s) for a minimum duration of 30 minutes. The required water supply for one- and two-family dwellings having a fire flow calculation area in excess of 3,600 square feet (334 m2) shall be 1,500 gallons per minute (95 L/s) for a minimum duration of 30 minutes.
Exception: A reduction in required flow rate of 50 percent, as approved by the code official, is allowed where the building is provided with an approved automatic sprinkler system.
Buildings other than one- and two-family dwellings. The water supply required for buildings other than one- and two-family dwellings shall be as approved by the code official but shall be not less than 1,500 gallons per minute (95 L/s) for a duration of 2 hours.
Exception: A reduction in required flow rate of up to 75 percent, as approved by the code official, is allowed where the building is provided with an approved automatic sprinkler system. The resulting water supply shall not be less than 1,500 gallons per minute (94.6 L/s).