FLOOD10363 ‎(2)‎

• County: Gunnison
• Community: Gunnison County
• Stream Name: East River, Cement Creek, Alkali Creek, Ohio Creek
• Title: Gunnison County Flood Hydrology, Contract # W99-D-0018 Final Report
• Date: 11/1/2004
• Prepared For: US Army Corps of Engineers, CWCB and Gunnison County
• Prepared By: Tetra Tech, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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5.10 TAYLOR RIVER BELOW TAYLOR PARK RESERVOIR

5.10.1 Description of Taylor River below Taylor Park Reservoir

Taylor River below Taylor Park Reservoir is located just downstream of the Taylor Park Reservoir. The
Taylor River at this point has a total drainage area of 254 square miles at the gage. There is an extensive
record from the Taylor River below Taylor Park Reservoir USGS gage (ID# 09109000).

5.10.2 Flood Records for Taylor River below Taylor Park Reservoir

The Taylor River below Taylor Park Reservoir USGS gage is located in this reach. This gage provides a
record of reported peak flows for 1938 through 2000. However, since this gage is affected by the
operations of Taylor Park Reservoir, the regulated data is transformed to unregulated flows by accounting
for the daily change in storage (see Section 4.3). Unfortunately, daily storage information is not available
for the Taylor Park Reservoir (construction began in 1935) until 1958. Therefore, there is a gap in data for
1935 to 1958, as unregulated flow data could not be simulated.

Since the gage is located just downstream of Taylor Reservoir, no lag is applied in the conversion to an
unregulated data set.

An estimate of the ratio of instantaneous peak flows to corresponding daily values is determined for this
gage using values from the Taylor River at Taylor Park located upstream of the reservoir. The ratio of
1.2481 peak-to-daily flows is determined by plotting a straight trend line for the data. The R2 value for the
line is 0.96 as shown in Figure 5.10.2.1. This ratio is applied to the maximum daily value for each year of
the unregulated data set to estimate peak values. The peak flows for the USGS gage Taylor River at
Almont are presented in Appendix A- Table A.10.

The REGFREQ program was used to determine the correlation of the available flow data to nearby gages
on the Gunnison River system. A high degree of correlation (>0.9) between the deregulated Taylor River
at A1mont gage and the following gages was found.

· Taylor River at A1mont (09110000)
· East River at A1mont (09112500)

The East River at A1mont gage was chosen to expand the data set for the Gunnison River near Gunnison
daily stream gage flows. The East River at A1mont gage has a continuous record from 1935 through
2000, while Taylor River below Taylor Reservoir has the same period of record due to the deregulation
procedure. The resulting family of flow records is presented in Appendix A - Table A.1 0

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