FLOOD01331

• Designation Number: 372
• County: Boulder
• Community: Superior
• Stream Name: Coal Creek
• Title: Flood Insurance Study - Town of Superior
• Date: 3/1/1979
• Designation Date: 1/1/1994
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

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5.0

INSURANCE APPLICATION

In order to establish actuarial insurance rates, the Federal Insurance
Administration has developed a process to transform the data from the
engineering study into flood insurance criteria. This process includes
the determination of reaches, Flood Hazard Factors, and flood insurance
zone designations for each floodinq source studied .in detail affecting
the Town of Superior.

5.1 Reach Determinations

Reaches are defined as lengths of watercourses having relatively the
~ same flood hazard, based on the average weighted difference in
water-surface elevations between'the 10- and IOO-year floods. This
difference does not have a variation greater than that indicated in
the following table for more than 20 percent of the reach:

Average Difference Between
10- and 100-year Floods

Variation

2 to 7 feet

1. 0 foot

One reach meeting the above criterion
the flooding source of Superior. The
on the Flood Profiles (Exhibit 1).

was required for Coal Creek,
location of the reach is shown

5.2 Flood Hazard Factors

The Flood Hazard Factor (FHF) is the Federal Insurance Administra-
tion device used to correlate flood information with insurance rate
tables. Co~relations between property damage from floods and their
FHF are used to set actuarial insurance premium rate tables based on
FHFs from 005 to 200.

The FHF for a reach is the average weighted difference between the
10- and IOO-year flood water-surface elevations expressed to the
nearest one-half foot, and shown as a three-digit code. For example,
if the difference between water-surface elevations of the 10- and
100-year floods is 0.7 foot, the FHF is 005, if the difference is
1.4 feet, the FHF is 015; if the difference is 5.0 feet, the FHF is
050. When the difference between the 10- and 100-year water-surface
elevations is greater than 10.0 feet, accuracy for the FHF is to the
nearest foot.

5.3 Flood Insurance Zones

After the determination of the reach and its respective Flood
Hazard Factors, the entire incorporated area of the Town of Superior
was divided into zones, each having a specific flood potential or
hazard. Each zone was assigned one of the following flood insurance
zone des~gnations:

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