FLOOD06898

• County: Statewide
• Basin: Statewide
• Title: Managing Floodplain Development in Approximate Zone A Areas
• Date: 4/1/1995
• Prepared By: FEMA
• Floodplain - Doc Type: Historic FEMA Regulatory Floodplain Information

Guide For Approximate Zone A Areas

Developing BFEs

EXAMPLE:, DXSCHARGE-DRAXNAGE AREA RELATXONSHXPS

The following is a Summary of Discharges table from a Flood
Insurance Study report.

TABLE 1 - SUMMARY OF DISCHARGES
FLOODING SOURCE DRAINAGE AREA PEAK DISCHARGES Icfsl
AND LOCATION lsa.. miles} 10-YEAR 50-YEAR 100-YEAR 500-YEAR
PINE CREEK
At confluence with
Saddle River 20.39 2,220 4,165 5,310 9,010
At Calvin Street 16.3 1,907 3,617 4,612 7,300
At Caitlin Avenue 14.9 1,860 3,285 4,090 6,570
ROCK RUN
Downstream of confluence
of Ramsey Brook 12.6 1,640 2,895 3,605 5,795
Upstream of confluence
of Ramsey Brook 10.1 1,390 2,455 3,055 4,910
GOOSE CREEK
Downstream of confluence
of Valentine Brook 9.1 1,285 2,270 2,825 4,540
Upstream of confluence
of Valentine Brook 6.2 965 1,700 2,120 3,405
COON CREEK
Downstream of confluence
of Allendale Brook 14.3 1,805 3,185 3,965 6,370
Upstream of confluence
of Allendale Brook 12.9 1,670 2,950 3,670 5,900

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Assume that Wendy Run is a stream within the same community as
the streams listed in the table, and that the Wendy Run
drainage basin, shown in Figure 19, has similar
characteristics to the stream basins from the table. First,
plot the drainage areas and corresponding 100-year discharges
on log-log paper as shown in Figure 20 on the following page.
Then draw a straight line through the plotted points as shown
in Figure 21.

At Property A, the drainage area for Wendy Run is 8.5 square
miles. Using the drainage area curve created from the Flood
Insurance Study Summary of Discharges table, the 10D-year
discharge at Property A is estimated to be 2,750 cfs, as shown
on Figure 21. At Property B, with a drainage area of 12.0
square miles, an estimated 100-year discharge of 3,600 is
obtained, as shown on Figure 21.

V-17

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