Section CC105 Distribution of Fire Hydrants
The average spacing between fire hydrants shall not exceed that listed in Table CC105.1.
Exception: A deficiency of up to 10 percent shall not be allowed when existing fire hydrants provide all, or a portion, of the required fire hydrant service.
NUMBER AND DISTRIBUTION OF FIRE HYDRANTS
|FIRE-FLOW REQUIREMENT |
|MINIMUM NUMBER OF |
|AVERAGE SPACING BETWEEN |
HYDRANTSa, b, c (feet)
|MAXIMUM DISTANCE FROM ANY POINT ON STREET |
OR ROAD FRONTAGE TO A HYDRANTd
|1,750 or less||1||500||250|
|7,500 or more||8 or moree||200||120|
For SI: 1 foot = 304.8 mm, 1 gallon per minute = 3.785 L/m.
- Reduce by 100 feet for dead-end streets or roads.
- Where streets are provided with median dividers which can be crossed by fire fighters pulling hose lines, or where arterial streets are provided with four or more traffic lanes and have a traffic count of more than 30,000 vehicles per day, hydrant spacing shall average 500 feet on each side of the street and be arranged on an alternating basis up to a fire-flow requirement of 7,000 gallons per minute and 400 feet for higher fire-flow requirements.
- Where new water mains are extended along streets where hydrants are not needed for protection of structures or similar fire problems, fire hydrants shall be provided at spacing not to exceed 1,000 feet to provide for transportation hazards.
- Reduce by 50 feet for dead-end streets or roads.
- One hydrant for each 1,000 gallons per minute or fraction thereof.
When public or private water mains are not available to supply fire flow [not within 1,000 feet (304 800 mm) of the proposed building], the following alternatives shall be used:
- When the adequate fire flow is not available and the water for sprinklers is provided from a source other than a public water supply, the amount of water to supply the system shall be calculated using the area/density method or the room design method as delineated in NFPA 13. The calculated duration of water flow to sprinklers shall not be less than 15 minutes to 10 heads.
- The sprinkler system shall have a water flow alarm monitored by an approved central, proprietary or remote station service or a local alarm which will give audible and visual signals at a constant attended location.
- When this alternative is utilized and the calculated water duration to a sprinkler is less than NFPA 13 recommendations, the area increases and fire-resistive substitutions allowed in Chapter 5 of the California Building Code shall not be permitted.