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<br />MAJOR PROVISIOl';.JS
<br />OFTHE' iK,
<br />RIO GRANDE C@MPAC'I' .~,
<br />
<br />,
<br />ALLOCATION OF THE FLOW
<br />
<br />t The compact was designed to stabilize the
<br />,) water allocation pattern in the upper Rio
<br />:.. Grifnde as it,existed in 1929:'Colorado
<br />received a right to quantities reflecting its
<br />f historic use tinder s-pecific flow regimes,
<br />, as did New Mexico for uses upstream of
<br />.( Elephant Butte. The compact required
<br />~ - that these users must leave the sal1l~
<br />:; general'quantity of flow in the river that
<br />had been deIiveredto the Elephant Butte
<br />i reach in the past. If the states wished to
<br />~ increase their upstream diversion beyond
<br />~ the 1929 level, they would somehow have
<br />:; to augment th~_, supply through salvage,
<br />',- conservation methods, drainage projects,
<br />i or trans basin imports.
<br />
<br />;, The.compactreflectstheB~rception dur~
<br />f ing negotiations that a guaranteed anryual
<br />;: release of 790,000 af from Elephant Butte
<br />t Reservoir would ptotedexisting down~r,
<br />~'.stream uses in Texas, New Mexico and
<br />:, M!;!Xico, In order-to ensure this;amountof
<br />; release, ,the compact est~blished delivery
<br />, schedules for the upstream reaches,. '
<br />~. these schedules dictate that Colorado
<br />:,' and New Mexico administrators must
<br />(In,alyze streamflow data each year to ~re.
<br />"dict the amount of runoff entering the<
<br />; basin, calculate the state's delivery
<br />: requirement, and regulate the water use
<br />, to ensure that the delivery obligations are
<br />~. niet~ 'The specifics of these scheduled
<br />~ delivelY requirements for each state are
<br />: .summarized below.
<br />
<br />.' C<?LORADO'S DELIVERY OBLl9ATJ()N
<br />
<br />,~, During a typical runoff.year, Colorado
<br />~:rnust deliver appro~,!mately one. third of
<br />i: the total Rio Grande flow to the:New
<br />Mexico state line in accordance with COm:'
<br />pact requirements. tn a year of high run-
<br />off, the compact deliveryschedule
<br />increases this obligation to over 50%';
<br />while In dry years; Colorado must deliver.
<br />only about 20% of the Rio Grande to New
<br />Mexico.
<br />
<br />The compact divides the Rio Grande
<br />~ drainage in Colorado into two sub. basins
<br />~. with s~parate delivery schedules, The
<br />Conejos River sub~ basin and Rio Grande
<br />rnainstem sub-basin are each thoroughly
<br />gaged and measured to ~nsure that the
<br />~ delivery schedules can be met. Inflow
<br />; into the Conejos basin is measured by
<br />j totaUing the flow from gages on the
<br />basinisthree_major tributaries (Conejos,
<br />Lo's Pii-lOs,and San Antonio rivers). The
<br />ouiflow requirement is then monitored at'
<br />t ;gages near the mouth of the Conejos River.
<br />I
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<br />--
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<br />For the Rio Gr,andemainstexn, the gage at
<br />Del No~e is used to measu~ irlflow,.wi~h
<br />gage measur{!meritS"Justnorth gf the Neo/'J
<br />Mexico border used to monitorcompli~
<br />ance with'the,delivery opligation from the
<br />Rio Grande. Colorado'soveraU annual
<br />obligatio(\,is the S,?V'- of the Rio Gran.~e
<br />mainstem an~ COI)ejos qeIivery sched~
<br />ulesminus 10,OOOitf.
<br />
<br />NEW MeXICo's, DELIVE~Y OBUGATI9N/
<br />" . M'
<br />The amo~ntofWater;,tll~tNe'W M:e~!Co
<br />must deliverto'Elephant B~tteis', S iIt
<br />predicted ,on asiritUar s0ed~~,in ,the.
<br />compact.;"Th~ staternu~J~,,~e,t~et~_, .
<br />about 60% of th,eRio,Gra.~de f1o'Y,pas~mg.
<br />theOto~i gage (lpcatedaf~~Jnil,~sot1tJl"
<br />of Espanola) l'€aches. Elephant ~Ulre
<br />Reservoir.During extriHn~lYWet y~ats};
<br />hO\o\'ever,~his!equiremen't;jnsreaS~~ to
<br />ove'r80%. >t '!iJi ~~
<br />,'" ......--'.."1 ':' .":.:.' . ,.:.," . ,".:,
<br />Arbite IV of tli~ compactdeta~$ tl1,~ deliv~
<br />eiy'sc~Cclul{!JotN'~w Jyi~xicoaS-e~t~9~
<br />I1shed iri-1938:This'schedulc, howevttr;'is:
<br />ob~'oletedueto..~a_:re$91~tk~n oithe:c:::Of!\~,t'i
<br />~ct.~orn.lnissionil1:'194~fJIl th<1t year,;~lle'
<br />Commission moved,jh~locati()n of the
<br />downstre,~,W gaping s~atiqnfrr)mSan:'"
<br />Marcial (just above Elephant ~1.!TteReser':
<br />voi.r)~o a pOintl?eJbw the:~~m~A'n~ew:;::
<br />de1ive!ys<;hedule,!fo~t,1Vite<1'1h or9-er to
<br />reflect this cha~~e j~ mo~itorittg location,;:;
<br />can befou~d i~:any'pq,st~~:9_48rann4al ,;J,
<br />report'following'tl1e tex't o{the"o,rigir\~I
<br />compact" II!-, "
<br />
<br />~oorF!~:..yrIo~NSTO REFLEc;:T' ONadiN~ ~~
<br />DEVELOPMENTS
<br />TI,e'basic calculations' for~ttri~water
<br />,inflo~rand dtIiVery'3'l,1tflow must qe(
<br />~OdifiedtR're~,~~tcn~?geSjh: y.,'_' ~
<br />a: Post;1929 diversicms'madeabo\'e
<br />"'" :.~' . ",,,:,,:."':::.,, ,"'" . :" "'~
<br />s;rtheiriflow ind,e,x'gagesinthe":
<br />'respe;,cHve states; ~~-w
<br />b.':TranSba~h{'~r6'rts;'.i
<br />
<br />c. OperatiOn' ofpo~t:conwacfreset-:,1'II1
<br />voir~j;aboy~t~e infl~~ index~~ge~.
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<br />DgaITS
<br />-, .. \llji. ....
<br />The COOlpact does not r~~H:iie:,thatNE!w
<br />Mexic<,J andColorad9strictly adpere"to
<br />:the sC,hedui~d '~el~,ye'ryrequirement$ each
<br />and every year~-:T;he states are allowed to
<br />underdeJiver in accordance ...vith the foJ~
<br />lowing conditions: ,"}
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<br />NEW MEXICO DEBIT liMIT t'i;.
<br />;. ;'.' ..:' .'11
<br />New Mexico m~y,not bech~rge~lVitH'a
<br />debit of moretha'h, 150,OOO~f in any one
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<br />12
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<br />(811
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<br />banks of the Rio Grande,
<br />
<br />The MRGCD also made plans to con.
<br />struct a storage reservoir on the Rio
<br />Chama to provide irrigation water. In
<br />1928, it issued a proposal for EI Vado
<br />dam and entered an agreement with
<br />the U.S. Department of the Interior to
<br />provide irrigation water, flood control
<br />protection, and drainage assistance to
<br />the six Pueblo Indian tribes in the
<br />area (Cochiti, Isleta, Sandia, San
<br />Felipe, Santa Ana, and Santa
<br />Domingo Pueblos), The District
<br />issued bonds to finance the project
<br />and, in 1935, EI Vado became opera,
<br />tional. Bonds were also sold in order
<br />to finance other District projects and
<br />activities which were to be repaid
<br />through the collection of property
<br />taxes,
<br />
<br />
<br />Although the MRGCD projects were
<br />somewhat successful in reclaiming
<br />waterlogged land, it soon became
<br />apparent that additional assistance
<br />was needed. High runoff and
<br />sedimentation in the early 1940s
<br />reduced the channel capacity of the
<br />Rio Grande, thereby aggravating
<br />flooding and other problems, As a
<br />consequence, help was requested
<br />from the federal government.
<br />
<br />THE FEDERAL ROLE UNDER THE
<br />1948 FLOOD CONTROL ACT
<br />
<br />\1!
<br />
<br />In 1942, the Corps of Engineers
<br />initiated a water resources investiga-
<br />tion in the Rio Grande basin of New
<br />Mexico. The Bureau of Reclamation
<br />joined the effort and, in 1947, the two
<br />agencies issued their reports to Con-
<br />gress. The reports recommended that
<br />the Corps rehabilitate old levees and
<br />construct additional flood control
<br />structures, and that the Bureau work
<br />on channel rectification and the
<br />rehabilitation of existing drains and
<br />irrigation facilities in the middle val-
<br />ley. As a part of the flood controi
<br />measures, the reports proposed con-
<br />struction of three dams: Chiflo Dam
<br />(on the mainstem of the Rio Grande
<br />in the gorge which is currently desig'
<br />nated a Wild and Scenic River),
<br />Chamita Dam (on the Rio Chama five
<br />miles upstream of its confluence with
<br />the Rio Grande), and the Jemez Can-
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