FLOOD10780 ‎(3)‎

• County: Delta
• Community: Delta County and Unincorporated Areas
• Title: FIS - Delta County and Unincorporated Areas
• Date: 3/15/1984
• Prepared For: Delta County
• Prepared By: FEMA
• Floodplain - Doc Type: Current FEMA Regulatory Floodplain Information

moderate duration of floodflows. Flooding from convective-type
cloudburst storms is characterized by high peak flows, short
duration of flow, and relatively small volumes of runoff.
Because cloudburst storms are small in areal extent and short in
duration, they do not constitute a flood threat on streams as
large as the Gunnison, North Fork Gunnison, or Uncompahgre
Rivers.

Historical references to floods on Gunnison River extend back to
1884. In that year, early high temperatures in May and June
resulted in the largest known snowmelt flood on this river. At
the City of Delta, Gunnison River was reported to be 10 feet
above bankfull stage, with an approximate O.75-mile width. Many
wooden bridges along the river were destroyed by this flood.
Peak flows of the larger historical floods on Gunnison River are
shown below (Reference 5).

Year Date Peak Flow (cfs)!
1884 July 2 50,0002
1917 June 18 25,000
1920 May 23 35,700
1921 June 15 30,100
1928 May 3 21,400
1929 May 26 23,100
1933 June 2 19,000
1941 May 14 27,500
1942 May 27 21,900
1944 May 17 27,200
1952 May 6 23,300
1957 June 6 27,800
1984 June 7 25,500

IMeasured at U.S. Geological Survey stream gage No. 09152500 at Grand
Junction, Colorado (Reference 5)

2This value obtained by estimation of flow on the Gunnison River with that of
the Colorado River

According to records from u.s. Geological Survey stream gage No.
09132500 on North Fork Gunnison River near Somerset, the highest
flow of record occurred on June 4, 1957, wi th a record peak of
7,680 cfs. The 1957 flood had an estimated recurrence interval
of approximately 45 years at the gage site (References 6, 7,
and 8).

7