|
<br />
<br />
<br />_ __ _.:1.,-
<br />
<br />THE FISHERY OF-'l'HE-LO~:';--~OO" LO;;~M-':'~~-=-=':""=':"::'I1-,c~'::fE~~;j-'7G'~~:
<br />"_!;:;"_:::;;:;'~,_ 1'''~ ~ .PIJ....&:&.ltI ~ / ,~:;/,~),-'
<br />:f.;-";' , _ ' , ',' .-' ::;. :..., .c. ~
<br />;;"~ing rivers unite to form the Colorado, which rolls, a mad',~.~~~'fS~,~:t.~::
<br />~~.into the Gulf of C~orDia. " -; "'. " .', ,j,:;./,~t.(''i~.tf;
<br />~,:the source of nearly aUlts water m the high mountams, but cr':,::::;~<~i;'
<br />;~~""8e through the arid plains and tab!e lands, it has cut a deep.<L-'~tgj:,
<br />"f' ~rge for more than a tho~and miles. Year after year the . ~Jit~:..
<br />. ':deeper and deeper, and carrles thousands of acre-feet of si1t.c:"'~s.F'c~
<br />:;.Today, Boulder Dam marks the end of this canyon region, , .:'=,;';::s.:c:'
<br />1Ley to the lower Colorado. Since its completion in 1935, the
<br />,,!.no longer rolls mad and turbid, but has been changed into
<br />lIoD.d more constant stream whose flow can be largely controlled
<br />
<br />.~!t~llJdei:lielLthe.Jm\'fr.basin~aJ~nd_Qf excessive heat and
<br />q1e:re the river flows at low' gradient'throtign:::-a-=-iii~~esSion of
<br />'~Erred by low hills or mountains alternating with narrow'
<br />,', es.-:--On ~ither. side it.is bounded by far-reaching deserts,
<br />-o:tributanes of rmportance enter the meam." ,....~,... ,,'
<br />,~es.below Yuma the force of the river is spent, and near the
<br />~""ary is the apex of its great delta. Here the land slopes
<br />i>guth, southwest and west. The stream now has a most
<br />--&.sit flows to the Gulf forming distributaries and lagunas.
<br />:w:atf>..r derived from seven states and Mexico, the Colorado
<br />.rourse of 1,700 miles. .'
<br />'Jeature of the river must be mentioned-its geographical.
<br />the Imperial Valley or Salton Sink. This basin, which is
<br />~by the Salton Sea, is separated from the Gulf of Cali-
<br />,~4elta-plain of the river. It is below sea level, the deepest
<br />.27,~,.feetbelow. Blake (1854) considered that it represents-
<br />?kead of the Gulf of California which has been cut off by the
<br />)~;Jfn,d.J;his belief seems to persist in most recent literature
<br />,}liesby Free (1914)--and Buwald'a and Stanton. (1930)
<br />inOSteonvincing alternate theory. These indicate that the
<br />.:,otinundated by the Gulf, but that it was sinking progres-
<br />,~r,.~:delta was growing. Thus, the river excluded the Gulf from
<br />~.zforming depression by building and maintaining a huge
<br />l~~~across the southern part of the basin. Waters from the
<br />),Sh~ting ~m its delta well above the level of the sink, have
<br />o.;this basm both before and since the advent of our historical
<br />~e:p~sent Salton Sea is the result of an accidental diversion
<br />fI11f~ the 1905-~907 period, which formed a lake 445 square
<br />"J. Smce then lts area has decreased to 287. square miles
<br />,,~~SUl'!ace about 244 feet below sea level. Despite a high
<br />~ra~, lts present level remains fairly constant because of
<br />.8Ul! ~:flow of waste irrigation waters through the New and
<br />~~,at lts southeastern end. These streams were old distrib-
<br />,the delta of the Colorado, but are now to be considered as
<br />~,es or wasteways. A number of intermittent streams also
<br />,from southwest to northeast.
<br />:--,plain 'or the lower river has been cultivated for many
<br /><Pi.the Indians, later by the Jesuits, and finally by the
<br />~~~y; 'The soil is fertile and the growing season is long.
<br />o~ water agriculture has been extended far beyond the
<br />fiat<;-to mesa lands and the great Imperial Valley.
<br />
<br />THE OOLORADO RIVER BASIN
<br />
<br />Ge,~eral Description
<br />
<br />Any account of the lower river must be preceded by a description
<br />of the Colorado as a whole.2 Its basin covers 1/13 of the area of the
<br />United States and part of northwestern Mexico. This is naturally
<br />divisible into two parts: (1) an upper basin, an area of high plateau"s
<br />bounded by towering mountainrange~; (2) a lower basin or desert
<br />country .of low plains broken by short mountaIii groups.---::-- ,
<br />MaJor John Wesley Powell has described the formation of the river
<br />in his book" First through the Grand Canyon" : "The upper two-thirds
<br />
<br />FIG. 47, The Colorado River between Blythe and Parker. Feb, 194~,
<br />
<br />of the basin rises from four to eight thoust.nd feet above the level lOf the
<br />sea. This high region · · · is set with ranges of snow-clad lal)l1n.
<br />tains, attaining an altitude above the sea var~ying from eight to f'JUrteell
<br />thousand feet. .All winter long, on its mountain-crested rim, snow falls.
<br />filling tJ:e gorges, half burying the forests, and covering the crags and
<br />peaks Wlth a mantle woven by the winds from the waves of the sea-a
<br />mantle of snow. When the summer-sun comes this snow me1ts. anJ
<br />tumbles down the mountain-sides in millions of 'cascades. Ten million
<br />cascade brooks unite to form ten thousand torrent creeks, ten thousand
<br />torrent creeks unite to form a hundred rivers beset with cataracts; a
<br />
<br />
<br />. In this report, the term "Iow('r river" usually refers only to that section !'elWeen
<br />the Neva.da.-Callforn\a. boundary and the Mexican boundary.
<br />
<br />( 114 )
<br />
<br />--:~."=;:;-----'~
<br />
<br />'.......:..~-~~,_.
<br />
<br />,-, ,.', ""'::'-~~'
<br />
|