WSP05517

• File Number: 8210.310
• Description: Colorado River Basin Organizations and Entities - Colorado River Water Conservation District
• State: CO
• Basin: Western Slope
• Date: 9/1/1996
• Author: US DoI - USGS
• Title: The Upper Colorado River National Water-Quality Assessment Program Surface-Water-Monitoring Network
• Water Supply Pro - Doc Type: Report/Study

The Upper Colorado River
National Water-Quality Assessment Program
Surface-Water-Monitoring Network

... t.,"
'..~ - '..'

Upper Colorado Ri\cr
Basin SlUd~' UnII
(snownin'n.-..Jj

National !'>iA WQA Stud)' Units
(,hown in gray)

, . ;....,

Plx~b)JohnElIi<l"

~~
G]S

U.S. Department 01 the Interior-tl.S. Geological Survey

I~TROl>l;(.."I()S

The U.S. GL'ological SUr-iCY began full imp1c-
mc-llIation of the Nitlianal Watcr-Quality AS.'>essmenl
(NA\\lQA) program in 1991. The long-tcml goals of
the NAWQA program are 10(1) describe current
walcr-qualit)' condition!> for a large part of the
Nation's freshwater ~tream... r1\'Crs. and aquifers;
(21 describe how water quality is changing over
lime; and (3) impro\'t~ understanding of the primary
nalUral and human facton. Ulal affect water-quality
conditions ILcahy and olhcl"\. 1990). To meet lhe~
goals. 60 slUd)' units representing the Nation\ mmt
importalll river hasin~ and aquifer~ are heing investi-
gated. The program design billalll.es the unique
as'iCssment requiremcnh or individual study unitlo
with a natinnally consistent deloign lotrul.ture Ihat
incurpl.lr.ltes a multis.cak. interdisciplinary appro;ll:h
for assessment of "urfaee and ground water.

The Upper CO]Or.lJ\) River Basin (Uccn.) js
one orlhe 60 NA\VQA study units: hydrnlogi;.: and
water-qualilY as"cssments of the VCOL began in
1994. The slUdy unit has a drainage area of about
17.800 mi:!. and Ihe primary riwr within the basin.
the Colorado Rj\'~r. originates in the mountain.s of
centr,J] Colorado and lIows about 230 mi south" c"t
into Utah. ~tajor tril;lutaries 10 the Cllloradll River in
the study unit are the Rlue. Eagle_ RlIar1ng Furl...
and Gunni..on Riven>. The Colorado River i" Ihe
majnr supply of water 10 lhe MluthwC'slem United
Statn. Streamflow from the sludy unit ilccounts for
ahout 4() percent of the ,treilmflow uf the Colorado
Ri....er at Lees Ferry.

The UCOL sludy unit is di\'ided aln1OS1 equally
into t.....o physiogmphic provinces-Ihe "outhern
Rocky Mountains in the easlern part and the
Colorado Plateau in th.:- .....estern part. The Southern
Rocky Mountain pnl\'ince is char;u:teri,t.'lJ I;ly north-
northwe~t-trending mounlains of cT)'stalline rock:-.
thai mnge in ek....ation from 11.000 to more !.han
l~,OOO ft. The Colomdo Plateau province nms,st;;
of high plateau, of sedimentary rocb .....ith elc\'a-
tion.. mngill!; from about 5.500 to 8.500 ft.

Land use. c1a<o;sitied as ran!!e1and or fore't.
acC(lunt" for about 85 pereent of the ba~in. ~ (lther
major land u"Cs in the basin are agriculture. mining:.
and uman. Surface .....ater U'iCd for irrigation
account<. for al:ll.1ut97 perrem of the tolal offstream
watc:r use. A surface-water-monitoring networl.. for
the CeOL ~lUd)' unit was de,igt1('d consit:kring the-
critical natural and human fadors Ihat affecl surfa\.'C-
.....alc:r qualilY in the basin.

\\ATER-QllAUTY ISSLES

The follo.....ing walc:r-quality is<,ue" in the
UeOL "lUdy unit have been idelllified as high-
priority local-scale issues of concem to Slate and
local water-resource managef'.

.Effects of in<:reasing urban de....e1opmem
.EffeCh of hydrologic modifications
.Effects of melal mining
.Effects of nonpoint- and poim-agricultural SOUTl'CS
.Effeds of ~linity frum natura!. agricullur.d. and
municipal 'ouurces
A national -.calc loynthesilo of the results
gencrak-d by each NAWQA sludy unit is an inle-
gral cumponent of the NAWQA program. The
national synthesis allows a comprehensive assess-
ment of specific: water-qualit)' issues at a national
seak by I.:omparati\'e analysis of individual ..tudy-
unit findings. Natiunal synthesis ha" identified
re'ticidc:lo. nutrients. and \'olatile organic contami.
nants 10 be the most important national water-
quality I,,"ues. These local and national ilosues will
partially be addre'scd by the use of a network of
surface-waler monitoring ..tat ions in lhe VeOL
loludy unit.

.""
J.......... -'J'I\"
.....n. ....
\ l' ...."" \
'~, l<'oO!- L
7cL _,1'(", ..J
:... ;f~ .,.~. ". ~
"". ~..... J
'~"'M.f '!)"
':_~_ ........'__ "''''''IT
\'"....s~,!
~...~.. "",. '- .
~.. ..--
., \ 1>f11:1,~ - '-
) '~_j''''-----1M''''''''' [
-~'- ""--..
"'__1 ~ ~~ ..:.>-.'\.
.......-,..". "i:", :.\~ ~'<.I,;"r.i
......u ~-,,\
..__ ~""",......l C
v~~

,..
.1-"....
-
V"

.~
~..--l.
""U"UI[~'

'\-

-,

t.\PI.,"\HI"
_ CnunIy 8.-'01)
-tm",~.

a 20 __
I,', '
a 2111 ..,1l.I.ClWFI'1;1ll8