YAVAPAI COUNTY, ARIZONA Federal Emergency ... - FEMA Region 9

Pipe Creek
Railroad Wash
Silver Springs Gulch
Unnamed Creek A
Unnamed Creek B
Unnamed Creek C
Unnamed Creek D
Unnamed Creek F
Wikiup Creek
Wilber Canyon Creek
Some streams, or portions of streams, studied by detailed methods in the
September 3, 2010 FIS were redelineated on more detailed and up-to-date
terrain data for this effort. Those streams include:
Beaver Creek
Bitter Creek
Cherry Creek
Copper Canyon Wash
Lucky Canyon Wash
Oak Creek
West Clear Creek
The Verde River was restudied by detailed methods from approximately 3 miles
upstream of the Tuzigoot Bridge in the Town of Clarkdale downstream to
approximately 3 miles downstream of the confluence with West Clear Creek in
unincorporated Yavapai County (a distance of approximately 41 miles).
Revised Base (1%-annual-chance (100-year)) Flood Elevations (BFEs), 1% and
0.2%-annual-chance (500-year) flood hazard boundaries, and 1%-annual-chance
floodway boundaries have been produced.
d. Hydrologic Analyses
For the Verde River, discharges for the 10-, 4-, 2-, 1-, and 0.2%-annual-chance
floods were computed utilizing USGS gage data for stations 09504000 and
09506000 in the Verde Valley Basin. The USACE Hydraulic Engineering
Center (HEC) Statistical Software Package (SSP) for flood frequency analyses
was used for the computations. Gage station 0950400 is located in Prescott
National Forest on the left bank, approximately 1.7 miles downstream from
Sycamore Creek and 5.6 miles north of Clarkdale. Station 09506000 is also
located in Prescott National Forest on the right bank, approximately 600 feet
upstream from Chasm Creek and 9 miles southeast of Camp Verde (References
1 & 2). Gage characteristics are provided in the table below.
Gage Number Drainage Area Period of Record Maximum Q Date of Max
09504000 3,503 sq. mi. 46 years 53,200 cfs 2/2/1993
09506000 5,009 sq. mi. 32 years 119,000 cfs 2/20/1993
The gage data for the Verde River were analyzed using Log-Pearson Type III
procedures based on the cumulative years of gage records, peak discharges, log
of discharges, variance of discharges, frequency factors, skewness, regional
skew, station skew, and weighted skew. The gage data provided an additional
30 years of record as compared to the previously-published hydrologic analysis
for the Verde River.
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