FLOOD07531

• County: Ouray
• Community: Ouray
• Stream Name: Uncompahgre River
• Basin: Gunnison
• Title: Floodplain Information Report
• Date: 4/1/1978
• Prepared For: Ouray County
• Prepared By: A & S Consultants
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

I

I

I

I

HISTORY OF FLOODING

I

I

Characteristics of the area, as described in earlicr sections are re-
flected in the flood history of the area. The steep rocky tributaries
~ithin confined basins flood frequently, and intensely. These aress
are notable 1n Oak, Canyon, Skyrocket, Portland, Cascade, Corbett, Fors-
man, Bl~'out, Plummer. Coal, Dexter, Cutler, Bridalveil and Cotton~ood
Creeks.

I

I

I

I

The broad, tl!-latively gentle reaches of the Uncornpnhgre River nonh of
Ouray have a much more timid pattern of flooding. Although influenced
strongly by cloudbursts in the nearby mountains, the raging tonents of
water are checked, their cargo of boulders, trees, $tu~ps and other de-
bris discharged, and their volume easily absorbed by the bro~d river chan-
nel.

I

I

I

I

The main populated centers within the study area are Ridgway and Ou ray.
Ridgway, located along the downstream broad gentle reach of the river, has
very little ~erious flooding potential. In faet, no ne"'spaper articles or
other historic records ."ere found to document floodi<lS of the Uncornp~hgre
River ~t Ridg"'''y.

I

UNCOMPAHGRE CHANNEL AT 7th STREET BRIDGE

I

I

I

Ouray is completely different. Six of the afore~entioned very steep and
rocky drainages discharge in th" in1,nediate vicinity of the town. These
drainag"s have had a long history of intense and devastating floods. The
earliest documented report ."as in 1874 and incidents of serious flooding
have been reported on at least 25 different occasions since. Unfortunate-
ly, flowr.."ords h,we nnt b"pn kept but some measure of flooding intensity
can be gleaned from resultant damages. A list of flood dates, d"tasources,
pea.k annu"l disch:.rges "nd d"ma.g" estlf:\ates i~ shown in T~bl~ 2.

I

I

I

I

:n~odl._n..8....2f tbe_Yro.':.<?."'-E,.a.h.s.re River

I

I

The earliest reference to flooding on th" Unco~pahgre River i~ contained
in the U. S. Geologic~l Survey's Water Supply Paper Q997. 1n reference to
the ."idcspread flooding which occurred during the spring and early summer
of 1884, it states "the melting of the heavy anowfall of the "inter of
1883-84 cau~"d r.he highest flood known on the Colorado and Gunnison Rivers,
in June 1884, and undoubtedly ca"sed sill1llar flooding On theUncom pahgre
River. The only available reference to such a flood, however, is an item
in the San Juan Prospector of May 17, 1884, which states that 'Uncompahgre
is rising rapidly and.",overflo." is feared'."

I

I

I

I

I

I

Gaging stations at various points along the Uncompahgre show tbat, during
the period of record (intermittently fr"m 1903 (0 present), tl1ehigl1est peak
annual flow occurred in 1921. This flow reached a volume of 2000 ds <It
Ouray, 2400 ch bel"." Ouray. and 4080 cfs at Colona. Other years of nn-
usu~lly high flo." 1n tl1e Uncompahgre River ."ere 1911, 1914, 1927, 1938,
1957<lnd1973. I"ter""U\\glyr<>.c"rdsfrornDall"sCrce1;nearRidgway,;,'"st
Fork Dallas Creek near Ridgway, and Cow Creek near Ridg."ay are no~ cOll~1s-
t~nt in ~howin~ COincident y~ars of high flow. This indicates considerable
v<lriation of snowfall accumulation and/or other factors such as rainfall in

I

I

I

I

I

UNCOMPAHGRE CHANNEL NEAR PORTLAND TOWNSITE. STATION 510+

I

I

-14-

'I
I

-15-