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<br />26./lfRb C''''''''J' Nr,,'S - N",'rm/,,, 2{~ 19"9 1::iJo /I..", i 7 ~
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<br />
<br />River users in a p1ckle
<br />
<br />'nw walers qllbe Colorado River
<br />,'. \ ',. \ . \ I I ,. \. '/ i ,/ (,. I 'I'! '( ~'i i( ) I ! c " I
<br />ill I VL.....;, 1)/11 lIu ulle ever cOllsid-
<br />ered Ibeproblelll qlsalinily
<br />
<br />/)rnininK ancinll.tttU
<br />
<br />fly Sieve J linduu;m
<br />
<br />
<br />A USTIN, Colo. - Gary"' harp
<br />digs into the shale hillside ahove where
<br />his irrigation ditch u-.cd to be and pull~
<br />out 8 slab of raw So.1h. holding it out lor
<br />me 10 see.
<br />Morc sail is vi.~ibrc behind him:
<br />thin, dirty-while bands runninR throll/o:h
<br />,,,ambling ~rrly tork. AI his fecI the
<br />CJOWll1 i.s liutttd with clumps or wcmh.
<br />~. '~qmb.
<br />u.u I'tttntly. those salls washed
<br />Ibo. Ounnbon Rhcr, lIllt: then into
<br />,lbe'eolorado River and eventually In
<br />California. Now they dlm'l.
<br />~. "CaliCornia oug/II 10 be proud of
<br />us". Tnarp says. lharp ami hj,~ son-in-
<br />taw Doran Eller me showing off their
<br />new inigation system. II lic.~ Iwo ami a
<br />hr.,); [:el below their bool.~, in a IS-inch
<br />pipe they burie>! la~1 spring.
<br />When it's fir.i.'li'ltXI, the system will
<br />~iJ.>C waler from Tharp's he.id~;.te or.
<br />Dry C:~ck across '....0 miles of billrcn,
<br />h;ghly salim' MlllleO!; sha!e in emerge
<br />onlO 111<, rid, \'nlrallfl- ~"il<; f,f Tk.'Il'<;
<br />
<br />Le Colorado i.~ a naturally sallY
<br />river, It drains 244,()CXl arid !;quare miles,
<br />mu-:h of il cmllposctl of marine shales _
<br />old M'a noms - rich in ~I!. AlmOSI half
<br />the river's sail con lent is from natural
<br />sources.
<br />The rest comes from development,
<br />wilh irri~at('t1 :l~ricu1ture the worst cul-
<br />pril. The problem comes when large
<br />am:)unts of water seep through highly
<br />....dine soillhat hi"'lorically rcx:eived only
<br />a few inthes nfrainfnll a yc.i1r.
<br />On the Tharp farm, for e:s:ample,
<br />irrigation water seeped into the ground
<br />where Ihe old dirt dileh crossed the
<br />Mnncos shale, 111al is very s..1line shal<"
<br />and as Ihe c.'lCapcd water percolated bad
<br />do.....n 10 the creek, il dissolved whalever
<br />sail'! il passed throu~h, adding over 560
<br />lOllS of sail a ye~1r to tlte Colorado Rivcr
<br />sySlem, according 10 Soil Conservalion
<br />Servke figure!.
<br />Th~ as.acre Tharp fanll is jusl olle
<br />of Ih(ltual"d.~ Ilia. alld sail to the river
<br />~"r!,..,,, 1(... I>;, ___I.
<br />
<br />the basin contrihute' another thtre r<T'
<br />cent. The diversion<; arc les, of a prob-
<br />lem bccau5C lhey remove hoth water and
<br />s..11t from the rivcr. evaporation remove!
<br />only w3ler.
<br />Jusla~ute"erywa'C'rprojc(1 inlhe
<br />~. t:-.T.'T ~ h~ C?:'!~ z:-r! ~.,..n
<br />tl~ un~' .qt'o,:k J'I'nJs ('r :l sm:1" 10\4-n ,
<br />sewagc system, adds 10 Ihe salt load. Ill.
<br />tic by little, year by y<,ar.
<br />Con.sidcred scpanncly the prohlem
<br />S('cms trivial, hul the comhined effen is
<br />trCIllt"ndou<;, '1 he Colorado now rick~ tp
<br />o\"('r nine million tons of saIl 3 )1.':1r.
<br />Rcccnl studies by lhc Burcau estimate
<br />Ihat tllOSC sail'! c:m<;e $3()() million a )"em
<br />in damllgc to <1gricuhural. municipal and
<br />industrial water users at the lo.....cr end of
<br />the ri\'er. Most of the dafl\a~e such as
<br />reduced crop yields. cornxted plumbin~
<br />and clogged car radiators occurs in
<br />California, which uses mOSI of Ihe waler.
<br />but Me:s:ito and Arizona arc also affect.
<br />cd.
<br />The waters of Ihe Colorado River
<br />.....crc divided among its sevcn basin
<br />states in 1922 by the Colorado River
<br />Compact. That documefll is aile of Ihe
<br />most imporlant polilical agreements in
<br />the lI1(xlrrn West. Howe"cr, it makes no
<br />refercnce 10 water quality or salinity
<br />evcn tllOugh, as each s~lle develops il'!
<br />share of the river, s..llinity levcls li.o;c and
<br />waler quality and Ihe waler's usdulnc.'!s
<br />drop.
<br />
<br />Mtrico critdfoul
<br />
<br />
<br />Sail ha'! nOI always beell a prob-
<br />lem on the Colorado. lIislorically, Ihe
<br />river aV<'HI,el'd about 4(Xl milli~rnm<; pcr
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<br />"'-'
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<br />C;af)'Tharp
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<br />Gulr of California, and the U.S. ~rilkd
<br />.....atcr from upsue.am re,~ct\'oirs to mall:
<br />up the diHercnce to Mexico.
<br />At the same timl:. ~tinity h:yt t...~:.~
<br />to cause Jlrohlt'm.<; on the U.S. sit.lc of thl:
<br />hurder, although those problcm$ "c:'rc
<br />more political than environmental. In
<br />1972, armed with tllC recently Jlas~ed
<br />Clean Water Act. the newly forllltd
<br />Environmental Protection Agency
<br />demanded Ihat thl: se\"c:'n basin statcs
<br />develop legal standards to limit rising
<br />salinity levels. The Statl:S. ....hith ha.j
<br />suecessrully resi,<;lCd similar federal pres.
<br />sure hefore, argued lhat 1101 enough .....a.~
<br />known about salt bthavior to justify
<br />atbilrary limil'. They also complained
<br />,hrll .~t:ltr.lin{' <:rarlll:Irf'~ "Pllld inlrrf,.,,..
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