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Layer: Fire Districts? (ID: 48)

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Name: Fire Districts?

Display Field: trs

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: In general, 1720 provides the following benchmarks:Urban Zones with >1000 people/sq. mi. call for 15 staff to assemble an attack in 9 minutes, 90% of the time.Suburban Zones with 500-1000 people/sq. mi. call for 10 staff to assemble an attack in 10 minutes, 80% of the time.Rural Zones with <500 people/sq. mi. call for 6 staff to assemble an attack in 14 minutes, 80% of the time.Remote Zones with a travel distance =8 mi. call for 4 staff, once on scene, to assemble an attack in 2 minutes, 90% of the time.There is a direct relationship between fire development, temperature, and time. Intervention is the strategy, whether it is through the use of automatic fire sprinklers or firefighters. Community resources dictate fire service capacity. The larger the town, the more fire stations may be needed. Having fire stations implies staff and equipment. Staffing presents an option, to a point volunteers are less expensive than paid staff, however the savings in personnel costs may translate into a higher community-wide fire loss. The distribution of fire companies (stations) is important and ISO looks for the built-upon area of a community to have a first-due engine company within 1.5 road miles of its assigned district and a ladder-service company within 2.5 road miles. Using a formula developed by the RAND Corporation (Expected Travel Time = 0.65 + 1.7 Distance Traveled), ISO set a benchmark criteria of an expected response time of 3.2 minutes for an engine company and 4.9 minutes for a ladder-service company in a defined standard response district. The formula has been validated on numerous occasions and yields an average speed of 35 MPH for a fire apparatus responding with emergency lights and siren (considering average terrain, average traffic, weather, and slowing down for intersections). The NFPA uses this formula in the 1142 standard. ISO determines standard response districts (SRD) for each existing fire station. An SRD for an engine company is a polygon defined by streets leading from the fire station out to a distance of 1.5 road miles. For a ladder-service company, the standard response district is a polygon defined by streets out to a distance of 2.5 road miles. The ISO then considers the number of fire hydrants within the SRD. (When fire hydrants are not available they measure the total linear road miles in the standard response district.) Thus, the presence of hydrants signifies a built-up area. They then identify contiguous built-upon areas in the community that do not have a fire station within the specified distance. If such an area has at least 50 percent of the number of fire hydrants (or, in areas without hydrants, 50 percent of the linear road miles) found in the SRD, they consider that the area may need a fire station. The SRD in cities with multiple engine company locations is the average number of hydrants served by the existing engine companies as determined by the total of hydrants within 1-1/2 mile areas divided by the number of engine company locations. Consideration may be given for excluding relatively low number hydrant stations as described below. (from ISO's mitigation website) (Note: This is only a cursory review of this subject as it applies to ISO's rating schedule criteria for response and station location.) In addition, the ISO provides exceptions to their response area coverage criteria for cities and towns lacking a hydrant system or only having partial hydrant coverage. The exceptions vary by state and are sometimes referred to as the suburban rule.Summary of the ISO Suburban Rule Exceptions:Properties 5 road miles or less to a responding fire station and with a hydrant within 1,000 feet are classified as being within the hydrant area. Thus, these properties receive better public protection classifications.Properties 5 road miles or less to a responding fire station and with a hydrant more than 1,000 feet away are classified as protected, but outside the hydrant system. These properties receive a lower public protection classificationProperties more than 5 road miles to a responding fire station receive the poorest public protection classification, essentially being without unrecognized protection. These properties receive the absolute lowest public protection classification.

Service Item Id: 137d9975c1df4214b64cdcea0496c4f1

Copyright Text: National Fire Protection Association (NFPA)

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