9317

• UCREFRP Catalog Number: 9317
• Author: Spahr, N. E., L. E. Apodaca, J. R. Deacon, J. B. Bails, N. C. Bauch, C. M. Smith and N. E. Driver.
• Title: Water Quality in the Upper Colorado River Basin, Colorado, 1996-98.
• USFW Year: 2000.
• USFW - Doc Type: Denver.
• Copyright Material: NO

61

traupol'te. 1'..... fl'_' tOM 1n the Lava-Chuar Creek dralMse to 31 and
47 toaa in the Koau.ent Creek and Cr,yatal Creek draiuses, respectively.
two of the ~I'ee debrle flowa .isnificantly cOft8trlcted the Colorado llver
at the tributary IIOUtU. The' frequency of debria nova that reach the
Colorado Ilt".r i. teotatl..., but the avaUable data sUlle.t one flow
reached th. Colorado UVer .".ry 20 to 50 year. in the.e drainages. A
c~ilatlOft of the .cantyhlstorlcal infor.ation on flovevent. fro. Grand
~ trlbutarie. , however, ,indicate. that debria now. occur IIOre
frequatly tbroupout tbepark.

'!'be bedrock .eolol1 of Grand Canyon National Park provide. an
ideal location for the, initiation of debria flow.. The high reUef
co.biDld with differential .trenath properties of the rocka leada to a high
potential for .lope faUure. . The lIO.t co.-on .ource of IIObllized
.'cliMnu for debris nova are the Herait Shale and E.planade Sandatone of
the Supai Croup. Other .ource. include the Kaibab LiIIe.tone. Toroweap
PoZ'Ution, aDd Coconino Sandatone; Muav Liae.tone and Bright Angel Shale;
aDd Quat.~ b..alt. in the ve.tem Grand Canyon. Dispersive and
...llina clay. in so.e of the.e for.atio~ aid in the initiation of debris
nova .

The aapitude and frequency of debria now. control the
hydraulics of the Colorado lliver in Grand Canyon National Park. Debris
nova fr~ the ...11 tributaries awade fana that typically force the
ri".r a..iMt the opposite vall of the canyon. The ability of...ll
draiDale. aucb .. Monuaent Creek to fora hydraulic controls (rapida) on one
of the largest ri"'r. in the >United State. ia of great hydrologic
.ipificAIICe. The debria fana. also cause now.eparation zones conducive
to deposition.. storage of sand on beaches, and reworking of debriafana
by Colorado liver di.charge. create. .econdary riffle. or rapida. Debris
nova are the .ource of large volUll8. of .and entering the river at
di.crete point., althoup the debria flow. occur infrequently. A thorough
UDder.taDcU.na of the "snltude and frequency of debria flow. 18 of
paZ'aIIOUDt WportaDce to 'anyundaratanclins or lons-tel'll e.tillate. of
.ediMnt trauport in the Colorado liver ln Grand Canyon National Park.

IDIUICIS CXTID

Apusm, I. P., , 1973'HIa.tillatil'lg.diacbaqe-.fr.oa-.uperelevation in benda:
- .AMrican Soclety of Civil Jnaineera, Journal of the Hydraulics
Divi.ion, v. 99, p. 65-79.

leverase, J. P., aDCI Culberuon, J. IC., 1964. Hyperconcentrationa of
8U8pIDded .edtMnt: AMrican Society of Civil Enaineer.,
Jouraal of the Hydraulics Divi.ion, v. 90, p. 117-126.

Blackwelder, Illot, 1928, Mu4f1ov .. a geologic asent in .elliarid
8OUIltaiu: Ceolo.lcal Society of .werlca Bulletin, v. 39,
p. 465-494.

lutl.r, It.er, &lid Huadortf, J. C.. 1970. ftooda of Decnber 1966 ln
outlaw.tera Utah: U.S. Ceolo.ical Survey Vater-Supply 'apeI'
1170-., 40 p.