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•;?:,.:__•? <br />? <br />reteasing water stored for 'tr "ition and <br />powez genecation is a flow ti that was <br />iateiy grovided under pre-deveiopment <br />conditions. FurtheRnore, oweng to the <br />?..,.?:o:^..•,. .,•.-___ lu--??- itt ?8 <br />g <br />?x75.i1? ,iy., v?... CG;ivi?ivna ai <br />Platte, teleases from Lake McConaughy <br />W(juld ?1P.P.f1 !(1 fIP p Patrvr f}ian 40-0 .r.?.c+ <br />because seepage losses and evaporation <br />between the release noint would occur <br />between the {ake and Grand Island, where <br />the 400 cfs flow rate is to be provided. <br />In same drought years, oniy a small part, <br />if any, of the released water would reach <br />vrand island even iT diversions in the <br />intervening reacti were to be curtai[ed <br />.. mp:e.ety. <br />vAt the risk of seeming pedantic, we <br />SIC a(Id1ItP thP fElllQwing eummWry nFnL; <br />observations and conciusions about the <br />Platte River: <br />t. The quantity of precipitatiot? oa the <br />area drained by the Platte varies widely <br />from one to another period but over the <br />long run now is no more nor no lcss than <br />ia the past. in ciiect, the annnal average <br />watcr supply availab)e for use has not <br />LfS''^.g..^`?... HCwC:Ci, usC Oi ttlZ a?ti2i WeiCI <br />has increased to the point that the av- <br />erage flow of the Lriver 1i DiSf:C3S; Uust <br />beiow the inflow Ezom the L.onp River} <br />has been reduced as much as 50 nercent. <br />Ie is necessary, however, to point out that <br />this large use would not be possible with- <br />out storage of the high fiows that for- <br />merly passed cluough the state unused_ <br />in other words, only the high flows have <br />been decreased (and beneFciatly so) <br />whereas iire reiurn f'iows and ground- <br />water seepage into ttie river have aug- <br />mrnted Lho .' i-^_ <br />.. ei u :?iy'Yreixi11C4 1n1oW. <br />HistoricaIly, the Platte River in the Big <br />Bend area was a milc or rnorP Nv,dc cx_ <br />panse of rushing water during tlie hcight <br />of the snowmett period and then became <br />a cibbon of dry gravel interspersed with <br />nazrow rivulecs of water for the remain- <br />der of tlie year. Auring some summers, <br />and particutarly during the 1930s drought <br />periad, even wading poois disappeazed <br />hom the river bed at Grand lsland. In <br />fact and accard:r.g to aju:y I980 report <br />of the Nebraska I3epartment of Water <br />Resources (DWR}--"in the twe]ve yea:s <br />ptioc lo consu-uction of Kingsley L?am, <br />ttie key measuring station on the Platte <br />Rivcr at Overton was dry for a portion <br />of each yeu." <br />2. Whereas periods of no surface flow <br />were nflt uncommon before the storage <br />was created. Uiey now are rare. Seepagc <br />to Ltie ::ve; f;arin i;e ;asge mound of <br />groundwater that eztends fmm Suther- <br />land ea5t te M?.^.drn a.^.d :!:2: wa5 C:eQied <br />by canal Iosses and ircigation seepage <br />has tended to increase in the 8Et, @end <br />area and may be even greater in the fn- <br />htrr W_ PSL' m^o'.v i...ai . . .. ' <br />• ?. ua ic iucrcd.ie i(3 <br />groundwater siocage is aboat 7 to iil- <br />lion acre-feet and that annual set?agP <br />retums to the Ptane are as much as <br />200,000 acce-ieeUyear from that source <br />alone. Return flaws upstream from t,alce <br />McCenaughy also hetQ siabilize the #low <br />of the Platte River_ DWR, in its 1980 <br />rcport, states, "-swruner inflow to Lake <br />hie?onaughy is oftcn 80 percent return <br />flow from upstseam developments." <br />?. F.°..`?'. Y..:.Y.e ::uucis:ni u ii n? i;e <br />Platte between Kearney and the mouth <br />of the Loup River naturally ??nds rn tese <br />Flow by seepage to groundwater on both <br />sides of the river. Before Europeans ar- <br />rived lhe wide ezpanse of the va1ley iand <br />on the north side supported a stand oF <br />tali grasses that probahly used as mctch <br />or more groundwater than now is used <br />by pump-irrigatett croQs. And an the <br />souch side, seepage loss was, and still <br />:C L?i? grouudV:aiei Siipyiy fii the nig <br />B[ue River basin. <br />4. SOIIIC pePpIg pC3CCEHC ihv pl8!tY'-_c <br />flowing in a lined conduit. That is, that <br />the river's ttow at a given locarion should <br />be no tess than at an upsuream ]ocatian. <br />Such a concept is unrealistic because the <br />t'iatte is intimately related to ground- <br />water in the afluvial deposits over which <br />it ;ows aad ihe river and floodpiain are <br />w[nerable to bigh evapotranspiratian <br />!osses. Q: c reach ..ay be gair?ing from <br />groundwater and another reach simul- <br />taneously Iosing to greundw.ater. '!?:e.e <br />is no guarantee that an addition to flow <br />at an uDStream npint w}ll stiil hrM ±n rbc <br />river at a downsiream point. Hisiory pro- <br />vides sorne insight in this regard. The <br />to[lowing excerpt is from the Tenth <br />Siennial Repori of the 5tate Board of <br />Irmgation, Sept. 1, 1912 to Sept. l, 1914. <br />['recipiaation during the period covered <br />vy tj'ie izpon was considereci to be about <br />average_ We quote, "Thc weather con- <br />ditio::s ase such o s;raZg €ac:m govern- <br />ing the amount of watex which is <br />necessary to have passing t+otlt R:idge_ <br />port and Notth Plattc that even with the <br />?ecords of the past season it is not pos- <br />sible to figure accarately the ezact <br />amounts. For instance, on August 6, <br />1914, there waz several bundred feet of <br />vracer passing the headgates of the ICear- <br />ney Cana] in excess of what they could <br />use. ?:s .-,ugss. S. u,e ;ver ai iCeatney <br />was absolutely dry. No water was avail- <br />able for uce b; die Ke2r.:eJ CA'r.;.l, yei <br />during this period there had been nine <br />hundred fifty to twelve hundred cut+ic <br />feet of water passing our gaging stacion <br />at North Piatte, and the incervening <br />ditches between Kearney and Nonh Platte <br />were using not to exceed three hundred <br />forry feet. This extreme Qecrease in the <br />flow of the river is easily accounted for <br />considering the wide czpanse of the river <br />bed and the foar days of exceeding3y hot <br />south winds on August 6th, 7th, 8th and <br />9th_" Transpiration by vegetation on is- <br />JancLs and on wetlands border.ng thc ; iver <br />alsa can account for water ioss from th, <br />river. Existing models do noi adequatet: <br />consider these losses in planning rive <br />reguiation. <br />5. Despite alI claims to the coatrary <br />the ct;i- <br />ieni t,ydrbivgit equiiibriun <br />reached throagh reguIatioa of river floC <br />ha,c in,rny:riea E.tie btRLfiw Ci flvw F?I`0 <br />tection, environmentally sound produc <br />tion of hydropower; water for i?*iga:ion <br />f1a1-water rccreation, and a signif'tcantl; <br />enhanced riverine habitat for migrator <br />waterfowl and indigenous species o <br />birds, 6sh and mammals. <br />6. The order for re-regulation of ce <br />leases from [rake McConaughy is ba8 <br />hyura;ogicaIly and economicaliy un <br />sound aed unrealisiic. <br />7. Ir. OL'S fL'dgTi?eni, the l?iaile ZSYC <br />and its tributary flows aze? very poorl. <br />undetstood by anyQLne who has ;;o: g:'sd <br />ied the rivers and their history. Misin <br />[ormation appeam to be the rvle rathe <br />than the exception, and that misinfor <br />mation is being disseminateri widely. Thi <br />Etow, storage, diversion, and manage <br />ment o[ the Platte R?ver are exceedingi? <br />?ouipiex. i.ndeed, many chastges havt <br />cecuaed over the Qast lUQ yeazs or so <br />wd these eF.as:g:s, iw, dc corr,piex. Ihi <br />issue of ee-regulation of water flows fron <br />those reservoirs licensed b; MRC i;. thi <br />western states for envirvnmentai pur <br />poses hopcfully witl be decicled on a fac <br />tua] scientific basis case by ease. Han <br />questions should be raised now.