Fire Flow

Fire flow is water available for the Fire Department to use to extinguish a fire. Fire flow can come from fire hydrants connected to a municipal water supply, water district, or water association or it may come from a stand alone system on your property. 
Residences
For residences, fire flow is required if the building is larger than 4,000 square feet, including all spaces, garages, basements, bonus rooms, etc.
Residential & Personal Storage
For residential and personal storage buildings fire flow is only required once you reach a certain square footage. That square footage calculation includes all usable spaces in the building, even if they are unfinished or just for storage. 
Detached Storage
For detached personal storage buildings, fire flow is required if the building is larger than 2,500 square feet.

Residential Building Fire-Flow Requirements Checklist

 
If the calculated fire-flow area* is greater than 4,000 square feet for a residence or greater than 2,500 square feet for a detached accessory building, one of the following options is required:

• A fire hydrant connected to a municipal or water association system is within 600 feet (driving route) of the proposed building. It must produce a minimum 500 gallons per minute at 20 psi for a minimum duration of one hour.

• An approved NFPA 13-D residential fire sprinkler system will be installed prior to occupancy.
Note: A separate Fire Marshal’s Permit is required.

• A fire flow system consisting of: a tank or pond, approved fire pump, and a fire hydrant within 600 feet (driving route) of the proposed building. The system must produce 500 gallons per minute at 20 psi for minimum duration of one hour.  Note: A separate Fire Marshal’s Permit is required.

*Note: Fire-flow calculation area shall be the total square footage of all areas within exterior walls, including only areas that are fully enclosed on all sides and which have a full ceiling height (6’-8” or greater). Area measured to the outside edge of enclosure walls. Breezeways connecting buildings will be included in the area measurement.