|
<br />./
<br />r
<br />
<br />\
<br />
<br />~--- - ... ..
<br />
<br />..-........ .u _"'IoIoJ.!..'.......:... ........ " L..
<br />
<br />~.......:..L.
<br />
<br />:.L::-'... . .
<br />
<br />.
<br />,"
<br />
<br />20
<br />
<br />Ga,l'lard V. Skag/!rhfH
<br />
<br />oS maf (about 60 per centt of lhis was from ground water reserves of which an estimated
<br />2.S,nmaf were in excess of the annual replenishment.
<br />The are~ of greatest use of w~ter for municipal, industrial and irrigalion purposes was
<br />the Phoenix-Tucson area of Arizona where most of the Region's ground water overdraft
<br />occurred. Las Vegas Valley. Nevada. lacking fucilities for diversion of adequate quantities
<br />of Colorado Rh'cr waler, was also pumping from ground water re.~erve.' in 196.5. About
<br />94 per c~nt of t,he 10ta.1 regional WOller withdrawal was for irrigation. and 6 per cent was
<br />for mUniCIpal. mdumlUl and all other uses. Only minor quantilies are used for electric
<br />energy generation, mineral production. IIsh and wildlife and recreation.
<br />
<br />Land II,'/!
<br />
<br />Land ownership wi~hin ~he LCRn is unique in that 64 per cent is in public ownership
<br />and only .~6 per ecnt IS ptlvate. Ahout haff the priVllte land is in Indian trust.
<br />The !eginn has a' wide variation in vegetal cover types and related categories that
<br />dc/ermine the .resour~'Cs, uses and developments that exist or may be projected. The
<br />~at~ral vegelatlOn ranges from desert through the chapllrtlll and mountain brush, pinyon
<br />Junrper nnd oak woodland, to Ihe yellow pine Bnd spruce-fir forest. to alpine and tundra.
<br />/ype on /01' of the highest mountains. The vege/ul COVer is dependent Upon the climate
<br />elevation. soil, geologic formlllion and topography. '
<br />About 2 per cent of the LCRB is in cropland; 64 per cent pasture and range; JJ per
<br />cent, forest and woodland; and less than I per cent in urban. transportation. utilities, etc.
<br />The cropland area is about 1.8 million acres of which 98 per cent is c1assilied as irrigated.
<br />The total area used for graling by domestic livestock is about 84 per cent of the total
<br />land area (Lower Colorado Region State .Federal Interagency Group. 1970.
<br />
<br />S".'n/(' mid r,'c:r"iI/IOIwl ri'.Wlllr..""
<br />
<br />Thc lower Colorado Rh'cr nllSin conlOlins many nlllura' wonders. hut ils hest known
<br />rhysicn,l realure hy far is the Gmnd CII1YI'n. More than 2110 miles lonll. the canyon
<br />ranllcs 111 .h'p.h from .l50() /0 6/)(JO f~'Ct nnd in width at the top from S II' more than IS
<br />miles. Its Ilrnndeur and imprcssiveness arc due in lurge part 10 the sculpture of its sides.
<br />Throughout much of its length the canyon appea~s in cross section 10 have a nat bottom
<br />or considerable width trenched by a steep-walled inner gorge; above this gorge. the
<br />almost horizon/al geological formations retreat in terraces edged hy c1ifTs from a few reet
<br />to a hundred feet high. except for the massive Redwall Limestone. about halfway up.
<br />which slands out in a spectacular clifT several hundred to a thousand reel high. Reds of
<br />nearly purc limestone occur ut II fcw spols in the inner canyon. particularly III the lower
<br />end of Marhle Canyon, where Ihe limestone surfaces arc intricately nuted with upriver-
<br />facing cusps ranging in size from I to 20 inches. Such nuting of limestone hy solution-
<br />anll silt-polishing is rare. The unique features of the Grand Canyon were recogniled
<br />early by the American puhlie, The Sltnta Fe Railroad made it u scenic allmerion by
<br />constructing a tmck 10 the south rim in 1901. ^ reach of canyon and river 132 miles long
<br />was reserved for the public by the creation of Grand Canyon National Park in 1919 and
<br />Orand Canyon National Monument in 1932 (National Academy of Sciences, 1968t.
<br />The LCRB encompasses 21 national parks, monument', and recreation areas which
<br />are administered by the National Park Service. Besides Orand Canyon Nitional Park,
<br />
<br />.........-. ,...~...........""'I.
<br />
<br />'.... ~. .v, Y.~.'.. '." . .
<br />
<br />-~"'"~----~. ~ .'
<br />': ...."'...
<br />
<br />00:.....,..-... ,. ~" ~.--...,.....
<br />
<br />-
<br />
<br />'lj
<br />
<br />..;.......' .....\... .......~. . A........~ ,....:...... ~ _ ... --' ......__ ........... .........
<br />
<br />-... ~
<br />
<br />-~
<br />
<br />Tile PIl.V-~lcal EIIl.ironment of the Colorado Ri,'er Ba.lin
<br />
<br />Zion Nalional Park in Utah. and Saguaro Nalional Monument and Orga~ Pipe ~actus
<br />National Monument in Arizona are examples of the .scenic splend?r avaIlable (FIg. 3t,
<br />Coronado National Monument in Arizona. and the Gila ChfT Dwellings Nallonal Monu-
<br />ment in New Mexico, are preserved as historical monumenu. lake Mead Nallonal
<br />Recreation Area. which includes Lake Mead with 162.000 surface acres nnd Mohave
<br />Lake with 211.200 surfnce acres. is visitcd hy millions nr peor'e each year (tower Color.
<br />ado Rellion Statc Fedcrnl Inleragency Group. 1'171).
<br />
<br />2\
<br />
<br />ENERGY RESOURCES
<br />
<br />The Colorado River Basin conlains a vast supply or energy resources. In particular, .
<br />potential energy sou~ces consist of oil shale. oil. uranium, oil Ilas. hydropower and
<br />geo.thermal resources. Eventual developmenl or the~e resou.rees derends upon the econ-
<br />omi~ of processing each particular resource depoSIt. In ad~llIon, resource extraction and
<br />conversion must he compatible with environmental restramts. Tb~ actual resources ulll-
<br />mately developed will depend uron a complex interchange. ~f aV~lIlable e~ergy resou.rces.
<br />waler resources. economics. environmental safeguards, polillcal mtervenllon and ptlvate
<br />resource ownership (Flug /!t al,. 1977). . . .
<br />The resources 10 be considered for large scale commercial develorment With SIgnIficant
<br />impact upon the water resources of Ihe Colorado River Basin are oil shale. coal and
<br />uranium. Known reserves of bolh oil and nalural gas WIll be tapped as each field
<br />becomes economically productive. The Increasing value of the~~ resou~ces, along With
<br />new teehnolollicnl development~ for increasing reservoir yields, Will permit. recover~ from
<br />deeper wells, ^" in 1111. the oil and gas lields are nOI e~pected to be a major contnbutor
<br />10 the tolal energy output of the basin. .
<br />
<br />I',rdrodc.'ctric pO\\'l'r r(!.'i(Jllrc'(',~
<br />
<br />lIydrocll'ctrk I,,""cr produclion o"l"inl'd an early slllrl in 1111' elcl'lric enl'r~\' indu~try
<br />of Ihe ('olurlldo Ilivl'r 1I,,,in. I'lIrh' ~cnerlllin~ insllllllllions l'Ul1siSll'd "r !l'IIII"",) \n"III
<br />units capllhle of supplyinll the p,~wer needs or small municipal associatil'n~. In Iatcr
<br />years. the Federal Government hecame the major devclorer of hydroelectric power
<br />within the basin. Most or this development has been accomplished by Ibe United States
<br />Bureau of Reclamation. At present. the Bureau of Reclamation ore rates over 90 per cent
<br />of the total installed hydroelectric resources or the basin, approximately 1200 megawatts.
<br />About one-half of the availahle hydropower rcsourees of Ihe hasin have hccn developed
<br />and lire compnsed of thc more desirahk, hydroelectric sites. TWl'nly-lwo pllll1ls with a
<br />cnpacily of some /J.~() megawalls comprise 1111 the hydroelcl'lric power whieh ha~ hccn
<br />constructed in Ihe basin (National Pelroleum Council, 1972). Other potential hydroelec-
<br />Iric planls arc expecled 10 resull from pumped storage projects or from Ihe imralla'ion of
<br />turhines to existing dllm~ to help meet peak demand capacities. Pumred storage ~hould
<br />nOI be viewed as a primary energy source but mlher as nn auxiliary source of slored
<br />energy.
<br />Remaining hydroelectric sites are generally in contlict with comreting water uses. and
<br />hydroelectric power development should therefore be considered only as one potential
<br />part or a multipurpose water resource project. In all. hydroelectric power presently
<br />account. for about I S per cent of the lotal national elcctric seneraling capacity and
<br />
<br />-
<br />
<br />'~" ,. "'~ ~. .~---.-
<br />
<br />""~oO;";" .{ ,"-\,.... ,
<br />
<br />"'~""'. _.~_...,....,. ~...- ., .~_.-.~ -....
<br />
<br />.'~ - -".
<br />
|