|
<br />;~I
<br />,
<br />
<br />. ~., 1
<br />
<br />C)
<br />o
<br />C")
<br />c..'
<br />-
<br />l-"'
<br />
<br />Consideration of the gage records provides a means of
<br />recognizing the effects of the water diversion facilities,
<br />including storage reservoirs and power developments located
<br />along and above the study area, on statistical flood magnitudes.
<br />
<br />The stream gage at the canyon mouth provides the longest
<br />record, 47 years including 1976, through an 89 year historic
<br />period beginning in 1888. This record was supplemented with
<br />stream record data compiled by the USGS on other front range
<br />streams. A total of 655 station years of record of front range
<br />streams was used in this analysis. The flood hydrology used
<br />in the 1971 Big Thompson River Flood Plain Information Report
<br />was also used in this report at the lower study limit (Ref. I,ll).
<br />The estimated flood discharges at selected locations within the
<br />study area and the discharges used in the hydraulic analysis,
<br />are summarized in Table 4.
<br />
<br />Table 4
<br />BIG THOMPSON RIVER AND TRIBUTARIES
<br />FLOOD FREQUENCY-DISCHARGE
<br />
<br />10-Yr.
<br />
<br />Discharge (cfs)
<br />50-Yr. 100-Yr. SOD-Yr.
<br />
<br />Location
<br />
<br />Big Thompson, west
<br />of Loveland
<br />Big Thompson, below
<br />Buckhorn Creek
<br />Big Thompson, mouth of
<br />canyon
<br />Big Thompson, below
<br />Cedar Creek
<br />Big Thompson, above
<br />Cedar Creek
<br />Big Thompson at Drake
<br />below North Fork
<br />above North Fork
<br />Big Thompson, below Dry
<br />Gulch near Lake Estes
<br />North Fork, above Drake
<br />North Fork, below Devil's
<br />Gulch near Glen Haven
<br />
<br />5,000
<br />
<br />5,500
<br />
<br />4,250
<br />
<br />4,200
<br />
<br />3,750
<br />
<br />3,700
<br />2,750
<br />
<br />2,250
<br />1,500
<br />
<br />1,450
<br />
<br />13,000
<br />14,600
<br />11,500
<br />11,400
<br />
<br />7,900
<br />
<br />7~850
<br />S,700
<br />
<br />3,800
<br />4,100
<br />
<br />3,400
<br />
<br />-12-
<br />
<br />19,000
<br />21,600
<br />
<br />16,900
<br />
<br />16,800
<br />10,500
<br />
<br />10,400
<br />7,500
<br />
<br />4,700
<br />6,100
<br />
<br />4,400
<br />
<br />44,100
<br />
<br />47,400
<br />38,900
<br />
<br />38,700
<br />
<br />19,300
<br />
<br />19,200
<br />13,600
<br />
<br />7,200
<br />14,100
<br />
<br />11,500
<br />
|