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- ~ . ~ - . Fort Collins Coloradoan 7 August 1976 ByGAYOOOK Of the Coloradoan It was 11:30 p.m., Saturday, July 31. The night of the Big Thompson flood. Bob Berling's telephone rang. He answered It. "We've lost the siphon." the person at the other end said. . Berllng is the project manager for th~ U.S. Bureau of Reclamation's South Platte projects. Headquar. ters: Loveland. The siphon 'Y8S. a small but in- tegral part of the Colorado-Big Thompson transmountaln water diversion project. As late as 10:30 p.m. Saturday the siphon-a 22O-foot pipe that was nine feet in diameter and weighed a quarter-mUlIon tons-had spanned the Big Thompson River at the Narrows, carrytng 500 cubic feet of water per second to Horsetooth Reservoir. Sometime during the next M minutes a building, whipped down the canyon by floodwaters, hit a support brace on the south end of the siphon, knocking out the brace and dumping the siphon tnto the water. Moving at III m.p.h., the flood- waters carried the siphon 600 yards downstream where It smashed Into a howe. The house was cnunpled by the impact 81ld the siphon twlsted like an empty beer can. The l3un>.au of Reclamation-and the Northern Colorado Water Conservancy District-had problems on their hands. Without the siphon, water from the Big Thompson project no longer could be diverted Into Horsetooth Reservoir. A part of the Charles Hansen Feeder Canal was Inoperable. And three of the Bureau's flve powerplants on the Eastern Slope were out. The lorge siphon smoshed into the side of house severol hundred yards down river Siphon knocked out, repairs under way 1930's droughts led to Big Thompson Proiect Lake Granby Is the primary storage By 9 p.m. the Bureau shut the facility for the collectiOn system. water flow off at Adams Twmel. By Green Mountain Reservoir was built this time addiUonal water from the to hold replacement water for the Western Slope was not needed. Western Slope. When It shut off the water at the ThIs system collects up to 310,000 tunnel, however, the Bureau lost the acre-feet of water annually-usually use of Its Marys Lake and Estes in snowmelt from the upper reaches powerplants. of the O)lorado River Basin. At about the same time the flow This water Is transported from the from Adams TuMel was stopped, western to eastern side of the the Bureau began wlUldrawing ConUnental Divide through the 13-"- water from Lake Estes at a mile Alva B. Adams Tunnel at the maxtmum rate and sending it rate of 5llO cubic feet per second. through the system to the Pole Hill According to a Bureau brochure, and F1aUron JXlwellllants. from the east JXlrtal of the tunnel ThIs was done to alleviate a "this water faUs a total of about possible strain on Lake Estes 2,900 feet as It flows through a series 1 created by steadily falling rain and of tunnels, canals, poweflllants and ....rising water in Dry Gulch. regulatingreservotrs." By 10 p.m. the Lake Estes water Included in the Eastern Slope was being pumped to Carter and system are Marys Lake, Lake Estes, Horsetooth reservoirs. The Big Pinewood and Flatiron reservoirs, Thompson Poweflllant also was shut Carter Lake and Horse-tooth down so water from that operation Re~rvolr and (he Marys Lake, would not be dumped into the Big Estes, Pole Hill, Flatiron and Bik' Thompson River. 'Thompson powerplants. .J. ~ this time, the Bureau was in I'''rom the east JXlrtal of1he Adarls .~Wtiit Berling called' 'a tight spot," Tunnel, the water flest drops into because three of its five JXlWeflllants Marys Lake Powerplant. At the foot were down-the byproduct of cur- of the plant, Marys Lake provides a tailing the flow of water from the forebay from which the water moves Western Slope. through another part of the system Nevertheless an equilibrium was and drops into the Estes~Power- being maintained-relIeving the plant. pressure on Lake Estes by moving Lake Estes Is formed by Olympus the water through the Pole Hill and Dam, which Is built over the Big FlaUron powerplants, generating Thompson River. It Is the afferbay power there, and moving the water storage for the Estes Powerplant. out to Carter and Horsetooth Water from there goes into another 'reservoirs. system then drops into the Pole Hill Anaen. as floodwaters rushed down Powellllant. the canyon, the siphon went. From there It Is routed t!'lrough .HQrsetooth was lost as a storage another system and dropped into the ;facllll)'. Flat1rQ.n Powerplant. ,;Ibe",Bureau had to redivert the 'll1ls'!~plant discharges into the 'Water" thereby increasing the Flatiron Reservoir, which regulates ~ on Pinewood, Flatlron and water for release to the foothills Carter reservoirs. storage.dlstribuUon system. Berling began to worry about the Southward from Flatiron F1aUron reversible pump, the only Reservoir, the water Is delivered to system for moving water from Carter Reservoir, located west of F1atiron to Carter Reservolr. Berthoud. Northward from Flatiron, Suddenly that pump became "the the Charles Hansen Feeder Canal key link," said Berling. transports water to the Bt'g'lThomp- U it went out power no longer son River and to Horsefooth could be generated at Pole Hill or Reservoir. . Flatiron-the only two powellllants UP TO 'llllS JXllnt the Bureau Is sWIin operation. . "un .."thin that ~ Sunday morning-Aug. I-a involved. <.>=<ause eve. J ......g ~tingency plan had been drawn happens Is essenUat to lts pg,wer ~ . operation. up:".. That operation annua)ly geQe~8"te8 0 Ifi-;the pump went out and the 760 million ldlowaU.hOUrs. most of aur.eau lost power at Pole HllI and which the Bureau markets to FJ&tlrim. It would ask other power various rural electricc06pi'i-ayves companies for assistance and Issue a and cities In O:llorado. I' ~til1c. appeal tor people to conserve According to Burea..ustat1s~cs, ~~t' was not suffIcient, Berling about 324,1XkJ persons 'In Colo'raOOI said the~Bureau would have had to are served with power generatecJ.. by OOnstdeli, releasing water down the the Colorado-Big Thompson project. Once the water is ilJ,.thef.90tJUus river so tt could generate some storage.distribution systf!~l1"J(~r W-er aiIMa.rys Lake and Estes. or Horsetooth reservolrs);,,_ the . !ibe'jitobf~mwlththat? Bureau of Reclamation steP-B oUt of ,i~ could have hampered rescue the picture, and In steps the.:,Nbr. 'fAt~~~ alternau~e, the con- thern Colorado Water Conservancy'""',,' District, managing the delivery of' ~nfYf.,pl4,n called for cutting seIIV1ce'wsome customers. supplemental water to irrtgatoryl Jiiit>~ > ,.-, and munlcipaJ.lndustrlaJusers,,_ 'MIT-WAs, the Bureau was able Fort Collins and Colorado,..St!l:te ~ina1nta1n voltage during the University receive some of tha~ fliXI~eve"rl though It took a week to water from the Soldier, Canyon.. 1 ~l;,tp-ee',~'erp1ants back on outlet at Horsetooth-the bWk,lof",the 1.IJ~t~ ttn Big Thompson project wa\ers go- to_ f~n&<f~". gency p1an~ was not Lartmer, Weld and Boulder coun- .~\ ti., :b1~ectrlc part of the ties. Morgan, Washington, J-Dgan " "~RiiJ Thompson project was and Sedgwick counties also rec~lvl) In .. aol5;t. rath",.. . -m" . -~.' ,.~ ~'6 au ... ',' -.,. ~'80;tOf the water dlstrlbution As long as the system works, that, ~paitj)f ICthough. Is'when Bob Berling's ieie..h~-;' ",' fi";sighon had to be replaced so . .;-.... "'~"~. ,t ~B1gThompsonwateragaln rang at Il.30 p.m. the ru~li~ 09li.e,\ ~"4codil be to d I H t th Big Thompson flood the devastal.tng 'I. s re n orse 00 weather conditions already had ReIe.lJ'oir. Big ,Tfth... interim something had to be ~O~~~I~j~~t.the CoIO~~. : doJI-w~i~J~:water moving through The first indication the Bureau of _.parrotl..!Jie;pharles Hansen Feeder Redamatlon had that the rains were ~~~ ,~came inoperable when heavier than usual was when Its the in ~entout monltortng devices registered r1s1ng 0 mon works also had to be water In Dry Gulch. re , d so .irrlgatlon users between By 8 p.m. the release of water the ~.. th,,~of the canyo~ and from Lake Estes to the Big Thomp- Lov ~_1!.; again could receive son was cut off because of the rising 8Up~mell~ water, . water in Dry Gulch. wr,:-_J.he siphon began the da~ ,. ~ - -- Once the Consf'rvanc)/ District had been formed, qualified electors in the district approved a contract with the United States government for the Bureau to buUd the project. In 1938 construction of the Colorado-Big Thompson project -estImated to cost $44 miIlJon-began. By 1947 the Bureau was generating some power, and the Conservancy District was dlstrtbuting some supplemental water. When the project was completed In the late 1950's the ,cost had climbed to $162 million. By then control of the facilities Integral to Its part of the project had been transferred to the Conservancy District. Under the terms of its 1938 con. tract with the government, however, the district had to repay only $26 mUljon of the project cost-over a 4O-year period and v.1thout Interest. It also had to pay for additional ~ design features it requested be built Into the project but which were not covered by the original contract. Repayment under that contract began In 1962. The Conservancy District meets thIs f1nanclal obUgatlon through water assessments and a one-mill ad valorem tax on property in the district. BEGINNING late Saturday nIght and lasting for a week, "We were in a critical, vulnerable position," said Berling. Ironically, the Colorado. Big Thompson project began to take shape in the mid.l930s - because of -.gh". According to a published report, "Dry winds were searing the arid lands from the eastern toe of the Rocky Mountains to mid-continent. Shortage of water supply plagued the Irrigators of Northern Colorado. " The agricultural economy was in jeopanly. Northern Coloradans In the South Platte River Basin decided to do something about it-to develop a supplemental water supply by diverting the headwaters of the Colorado River from the Western Slope of the Continental DiVide for use on the eastern side where ad. ~!!9nal..,lrr\&at1on~wa1en w.re. -needed to $.Qillze the agricultural economy. ., In 1935 Congress allocated $100,000 to the Bureau of Reclamation for a water diversion feasibility s1l,ldy. Concurrently, work was under way In the Colorado legislature on enabllng legislation for water conservancy districts. 1l1at legi8latlon-the Conservancy DIstrict Act of.Colorado-P'lSsed in May 1937. In ~ptember the Nor- thern Colorado Water Conservancy District was formed. It was the tlrst such district in the state. Today there are 36. By this time the water diversion project had been pronounced feasible, and Congress had authorized It. It would have two functions. One to generate hydroelectrtc power. The other to distribute supplemental water. The Bureau would be in charge of the power generaUng part of the project. Responsibility for water distribution would rest with the Northern Colorado Conservancy DIstrict, which had been created as a political subdivision of the state foJ' that pu~. TODAY THE Colorado-Big Thompson project consists of a water collection system on the Western Slope, a tunnel 3,800 feet below the surface of the Continental Divide, a. power system on the Eastern Slope and a foothllls storage-distrlbuUon system. Its service area covers 700,000 acres In the South Platte River Basin. On the Western Slope, four reservoirs, four dams, two pumping plants and canals and waterways make up the collection system. Familiar as popular recreational areas, the reservoir system consists of Granby, Green MOWltain, Willow Creek and Shadow Mountain lakes. Part of the siphon was used to make culverts for the tem- porory road back up the Thompson Canyon. after the flood when engineers were dispatched to assess the damage. In the three weeks that since have elapsed, the government executed a contract with Eaton Metal Products of Denver to make the pipe. And the Eagle O)nstruction Company of Loveland was retained to Install the siphon. As part of the siphon.replacement project, the Big Thompson diversion dam also wtIl be rebuilt and damage from soil erosion below Olympus Dam w1ll be repaired. This work will cost an estimated $1.1 million, to be shared equally between the Bureau and Con. servancy District. Although the district already has put up UOO,OOO in emergency funds for the work, Berling sald It should be reimbursed throogh the Federal Disaster Assistance Administration. The target date for completion of the siphon repalr Is Oct. 15. Although floodwaters knocked out " a link of the Colorado-Big Thompson cllain when lhey washed out the siphon, It could have been worse. r' Had an adequate amount of water " oot been stored In Horsetooth, the ..IConservancy District might not \have been able to meet the sup- plemental water needs of users served by OI.ltlets from the reservolr. , For starters, this could have had an adverse Impact on the agricultural economy. . As It was: there were 88,000 acre- feet of water In the reservoir, enough for the Conservancy Dlstrb:.t to meet the needs of lnigators and municipal-industrial users \through the rest of the season. However, about 600 users between the Big 'Thompson and Horsetooth weren't as lucky. When the siphon went, the part of the Hansen Feeder Canal. from whlch they derive their water, became Inoperable, leaving them without water. To ameliorate the problem, the Conservancy District Installed a temporary pump In the Big Thompson Rlver at the mouth ot the canyon. It ran a water line from the pump up over a hill to the Hansen Feeder Canal. And a power line to operate the system 'was brought in by. the Bureau. Two weeks to the day after the . siphon went dO\\on, Big Thompson River water was being pumped into the canal. .. Instead of moving at 500 cubic feet per second as It dld through the siphon, the water now moves at only 10 cuble feet per second. Nevertheless, the 600 users who depend on the largely inoperable partoftheHansenF~~rQm~are receiving some supplemental water again. It will cost the Conservancy District an estimated $25,000 to operate this temporary pumping system for the two months It w1Il take to replace the siphon. Again, Federal Disaster Assistance Ad- minlstration funds should cover this. FInally, numerous ditch com. ,panles and irrigators between the mouth of the canyon and Loveland were affected when diversion structures serving them were damaged or destroyed. Repairs, either of a temJXlrary or permanent nature, were completed wtthin a week or two alter the flood, Berling said. However, when the ftnal bill for that and other related work that mw.t~~~\n\t.......\V:Aa.l.. about S175,llOO; he added. So, the repair work to the Colorado.Blg Thompson project continues. <: By Oct. 15 or thereabouts the siphon-that small but integral I1nk in the system that was washed out by the brutal floodwaters that swept down the Big Thompson Canyon the night of July31-should be restored. When that happens the process of refl1llng Horsetooth Reservoir for the next irrigation season can begin again. A STl01l pump is now diverting water bock into the diver- sion p;oject. . \ . l