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<br />Historic Flooding and Flood Studies
<br />
<br />Streamflow records do not exist for Willow Creek. Information concerning possible flood flows and flood
<br />hydrology is taken from studies, reports, articles or data in the local area.
<br />
<br />A local resident of the Willow Creek subdivision indicated that some flood water and debris flowed down
<br />Sierra Creek (a north flowing tributary on the west side of the Willow Creek watershed) after the Million
<br />fire (oral commun., November 2004).
<br />
<br />The flood of October 1911 was probably the largest of record for many streams in the San Juan mountains,
<br />in which the Willow Creek watershed is located. A rainstorm of long duration produced a flow of 18,000
<br />fe/s (Patterson, 1965) in the Rio Grande River at Del Norte, Colorado, which was larger than the 500-year
<br />peak discharge recurrence (Federal Emergency Management Agency, 1987). This flood produced an
<br />estimated 8,000 fe/s peak flow (from high-water marks) in the South Fork of the Rio Grande at South Fork,
<br />Colorado. Large floods were also reported in the Rio Grande region in 1884,1905, 1927, 1949, 1957, 1970,
<br />and 1973 (FEMA, 1987). Perry and others (2001) summarized historic flooding, and detailed flood
<br />information at USGS streamflow-gaging stations during 1970 to 1989 (table I).
<br />
<br />Table 1. Maximum stage and discharge for period of record for streamflow-gaging stations having significant
<br />floods during 1970-89 in Colorado (Perry and others, 2001)
<br />[mi2, square miles; ft, feet above an arbitrary datum; f~/s, cubic feet per second; n, not detennined or not applicable; >, greater than;
<br /><, less than. Source: USGS WSP 2502; Recurrence intervals calculated from U.S. Geological Survey data. Other data from U.S.
<br />Geological Survey reports or data bases; Regulated flood, N, no; Y, yes]
<br /> Maximum discharge for period of Significant floods during 1970-89
<br /> record through 1994
<br />Station Station name Period of Water Dis- Date Dis- Regul- Recur-
<br />number record year charge (mmfdd/yy) charge ated rence
<br />(USGS) (ft'/s) (ft'/s) flood (years)
<br />08213500 Rio Grande at 1911-23, 1927 7,500 06/07/86 4,050 Y 50-60
<br /> Thirtymile Bridge 1925-94
<br /> near Creede, Colo.
<br />08217500 Rio Grande at 1951-94 1985 5,190 06/09/85 5,190 Y 50
<br /> Wagon Wheel
<br /> Gap, Colo.
<br />08218500 Goose Creek at 1955-83, 1970 879 09/14/70 879 N 30
<br /> Wagon Wheel 1985-91 06/16/87 761 N 20
<br /> Gap, Colo.
<br />08219500 South Fork Rio 1911-22, 1912 8,000 05/24/84 3,690 N 20
<br /> Grande at South 1936-94
<br /> Fork, Colo.
<br />08243500 Trinchera Creek 1929-82 1942 1,340 05/13173 1,070 Y 50
<br /> below Smith 1973 1,070
<br /> Reservoir near
<br /> Blanca, Colo.
<br />08245000 Conejos River 1952-94 1958 1,160 06/30/85 1,020 Y 25
<br /> below Platoro 1965 920
<br /> Reservoir, Colo.
<br />08246500 Conejos River near 1903-05, 1912 9,000 06/25/85 2,920 y 5
<br /> Mogote, Colo. 1912-94
<br />08252000 Rio Grande at 1954-82 1979 5,000 06/10/79 5,000 y 20-25
<br /> Colorado-New
<br /> Mexico stateline
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