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<br />MAJOR FINDINGS
<br />
<br />Urban Development is a
<br />Water-Quality Issue Within
<br />the Southern Rocky
<br />Mountains
<br />
<br />....
<br />"'"
<br />....
<br />Cl
<br />
<br />Reaealion in lhe mountains of
<br />C\llorado j, Decommg a ,igniticanl
<br />1;U1J-ll~e aClhity In many :trea".
<br />Urban lk\'cl(lpmenl and the infra.
<br />slruClUre 10 ..upport reaealion ha\"e
<br />II1creascd substantially in lhe 13..1
<br />lit'cade Hetwt'l'n IlJ90 and] QQ7.
<br />the populatinn im:rea.,.e in Sununlt
<br />and Eagle Counties ncct"Jed 4U
<br />perccnI (http://www.coloradu.
<br />edulllbranc-.../gll\'puh..h':lllollumhl
<br />cuunlics.htlnl. In additlun!O resj.
<br />Jt'nl population incn:a~l."s. "ca-
<br />.,(lnal population tluxes due 10
<br />re..:rcalion arc large. These tempII-
<br />f<try P\lpulalHlIl inl'reaSL's on:ur In
<br />winter during periods of extreme
<br />In\\' I1m\ ;lIld minimal dilluion in
<br />ri\'t~'TS and ..(rcams.
<br />Altlwugh urban dew]opmcnI
<br />may bt.' only a small (X'rcC'ntage uf
<br />Iota] watc-rshed area. Je\'cl\Jpment
<br />anJ tran"'portali()n "yqcm... lend 10
<br />bl' adj.l\:ent to riparian area... In
<br />mOUlHainous terrain dig, 6). Thb
<br />land. use p.l1tl'fIl has placed human
<br />purulalll1n~ in IOl...ati\ln~ that have
<br />the greatest dft"ch nn tht" 4ua]ity of
<br />thee' \\.l1er res\)urcl.'~, Surface- and
<br />ground-water stth.lie" were imple-
<br />1llee'lltl'J In lIl\'csligate Ihe water-
<br />4l1aht~ I...sue... in ur~an area... of Ihe
<br />S(luthem Rocky ~loumalns.
<br />Suda{'t'.n.ller...ludil'sirnc.,ti.
<br />j!OlIl'd Ihl' cffect.'; uf urban land
<br />1I.'l', T\\o stream-monitoring site,
<br />\\ ere !O\..att"J in area... of urban
<br />Jc\'e1opml'nt U1g. 6!- The Gore
<br />Crt"ek ,Ill' i... dllwnstream from
<br />Vail. anJ the East River silt" Is
<br />down...tft"3m from Crested Rutl\.'.
<br />D<..'\el(lpll1em in Vail is appn-.a..:-h-
<br />1Ilf: t-.uild-CHlI. wherea... Ihere i..
<br />pOlemi.11 f(lf IMge inne3$e... of
<br />Je\elopment inlhe Cre...ted Bulte
<br />,lre.l. Tht' Ct1h-.radll Ri\er tJc]O\\
<br />
<br />Coiot_Fl,_tJelowr
<br />BbIoMGuI<./'!(""",,""""sot.l
<br />'M.~I
<br />Southem Rocky Mountains Il-. I
<br />Physiographic PrOVInce -), """"-', -1: '
<br />
<br />COloradoPlaleau ~. )'. .l f
<br />'07 r ;-'~
<br />Physiographic Province I I. ~ ....
<br />, .,.y- 'L',." "~)-
<br />
<br />\~~'= Cob-JKl<>ea:: \ or' ,~ f '\-~~ " ~~.ra~
<br />u..~S\ll'.''''' .-- ~\ 'v--~, . :t '..~~2-.".SI""'_
<br />,,,' ~'v -" ~'-"\~;Th, .-
<br />" ,..,......... . ~,", '.. ),23\~. .174,)
<br />c. "",-. ,l..,..;t l, ',F'f.f-
<br />-- - ~,~,", -_'H);_\_;:''''''''_~:r':W''''
<br />__ '" .""'+. 5 ',~l...,..
<br />~ ..4 Grand' j . .f.. J ,yt ~Aspll<>' EXPLANATION
<br />
<br />';{:-~"" =1::::,7' ciS;;)'i,,':/~&;~~~,:~,~~~~ . :=r=:~
<br />I~-.. (~.. a~ .
<br />Gr_"....... ~.', '/ 26. 7 s_.S<O<l.....'"
<br />in~<Me . "i,,.... . 27 An It: ...-npIongS,~_.......-'
<br />.Y"OPI><.~fl' /. ,1'~j! .000I~ r' ..~_.
<br />\J'~;-.~-:.~~ ~'\. ...."Jbl*._.
<br />l!/"i, I" ..Gunnl-- ~SA.-.pio'lg
<br />~ ...... . -, .,--.......--.
<br />G,,~q~'''' - CoOIni.h.. r.--.~" ~~. .' ..~_
<br />...a-G'."ll.J'-"'CtO'l ~Y..:~~'\:\C~ I~-r-;-::::-''':)... 5....... """"""'C S>le
<br />/~, -J' "J.
<br />U",:",,"-'>gI'."-'") !:.......L..._~1 ,.....f ~ ~lvId'"
<br />,=O~'e /l&. .,- . Urtl...~"".....
<br />~..fl' - ...'IS 32 -\.. ,(
<br />~O oo:'~1,-"..3~- :::~
<br />~ .....,
<br />;>0 ~Cl 60 KILOMETERS
<br />
<br />Raker Gulch, a reference sile wilh
<br />Iinle urhan de\'e1opmem in the
<br />Southern Rt'lCky i\loumains. W3'io
<br />also ..all1p]ed monthly to pro\'ide a
<br />compari<,on with other <.ilc\.
<br />:\"lItrient cnneentnltiolls at
<br />sill'S in an'a... Hr urhan d('\ clup-
<br />ml'nt \\~r~ grl'ah'r than nmn'lI-
<br />IrotliHn.. ~tt Ihe rl'fL.rCll\'.. ..ilt'.
<br />Concemralions of nilnle p]ll..
<br />Illtrale and tOlal phn..phl)ru... Wl.'re
<br />slighlly elevated al Gore Creek and
<br />Ea..1 River compar....J to reft"ren':l'
<br />concenlration.-. I fig. 7l. Cuncl:ll1ra.
<br />liun... for nltrale were bL'1(lW Ihe
<br />!O.mgfL Colorado instrl.'am ...tan-
<br />dard at alllhree sites. L'n-jonill'd
<br />amllwnia (.{lllcentr:lIHlllS, l'om-
<br />puteJ from di..,,(llwd allllllllni;l,
<br />pH. amI tl'lllpt'rature. did not
<br />eXt.l'<..'d Slale in..trl'am slandards.
<br />Di..solved and orth{)plw"ph<ltt"
<br />
<br />,
<br />,
<br />
<br />"
<br />
<br />phosphoru~ cont'cnlfations were
<br />greater at Gore Creek lhan lhe
<br />other sill.'... Gore Creek and East
<br />Rj\'er are not wa~lewater.efftuent-
<br />dominaled stream.. such as might
<br />he found In kHge metropolitan
<br />areas: huwl'\'er. ..mall amOUIll" of
<br />nitrogee'n and pho..phorus can
<br />incrca..e algal grov.-,th and eUlrnphi-
<br />cali on pnX"cs..e....
<br />Thl' amounl tlf alj!<lt' and the
<br />I~'pl'.... ur aquOIlk iU\i'rtehrall'S
<br />linwdsl art:' inthll'lIl'cd h~' lIutrj.
<br />l'nl l'llridllll('nl frum lIr1mn
<br />..oun't's, TIll' amLlllln \If algae
<br />talg.ll hiO\'o]ullle! delermined froll1
<br />algae ..amp]es cnllected III 11)96
<br />and 191)7 wa...largc"t 111 Gore Creek
<br />(Iig, X I. where nutrient level... were
<br />higher. The pert'entag<..' of the invcr-
<br />tl'oral<..' (nmmunity repn:..emed by
<br />p\J!lulilHl 'l.'nsilivc in,ects
<br />
<br />Figure 6. Samplmg sites and study areas were selected to assess eHecls of urban.
<br />mining. and agricultural land uses on water quality.
<br />
<br />6 W;lIt'r Qtlallt~ in the l~pper Cl)!orad\) RI\'t'r Basin
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