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<br />
<br />than they obtained. That was in 1931
<br />when they could have used 30,000
<br />more acre feet of _ water for late fa.ll
<br />irrigation, Mr. Hansen said.
<br />Approximately 400,000 acre feet of
<br />water are all that can be collected for
<br />diversion in the Grand Lake vicinity,
<br />Mr. Hansen said. The plan _contem-
<br />plates collection of about 346,000 acre
<br />feet of this amount with delivery at
<br />320,000 acre feet to the eastern slope.
<br />The loss would be from evaporation
<br />and seepage.
<br />Three Lakes In Project
<br />Three lakes west of the divide
<br />would be in the picture on the west.
<br />ern slope--Grand Lake, Shadow Moun-
<br />ttl:in L,Cl,ke. aQjp~.,Grand-"Lake"both""
<br />t'o'"'b'e' >ke'j,t> at the same constant level;
<br />and Granby Reservoir, a large stor~
<br />age basin (storage capacity 482,000
<br />acre feet) at an elevation 150 feet
<br />lower. Water from Granby reservoir
<br />would be lifted - by electric pumps so
<br />that it would flow into Shadow Moun-
<br />tain Lake, thru Grand Lake to a 13
<br />mile tunnel emerging at a point in
<br />Wind River canon about six miles
<br />south of Estes Park village. _The tun-
<br />nel is planned to handle 550 second
<br />feet of water. From the ,end of the_long
<br />tunnel, it would be transported in
<br />closed conduit and pass under Giant
<br />Track - mountain, past Mary's lake,
<br />east of Prospect Mountain at Estes
<br />Park village and enter the, Big
<br />Thompson rlver a short way below
<br />Estes Park. The taU there of 745
<br />feet would be utiliZed to operate a
<br />power plant, pa.rt of the product of
<br />which would be led by transmission
<br />line around Rocky. Mountain National
<br />Park to operate free the pumping plant
<br />to lift the water 150 feet from Granny
<br />reservoir to the Shadow Mountain
<br />lake. This power plant .installation,
<br />estimated to cost $3,000,000 is calcu~
<br />lated to be self-liquidating and is not
<br />figured against the cost of the irriga~
<br />tion water system.
<br />The 'Plans also Include a scheme by
<br />which the diverted water might be
<br />carried further down east slope, if de-
<br />sired! to a 'point near the Forks hotel,
<br />where it could be dropped 1,236 feet
<br />to be used in a large hydro-electric
<br />plant.
<br />Will Supply Three Streams
<br />Once the water has been trans-
<br />ported down the Big Thompson, it
<br />will go into three channels or forks.
<br />The south fork would lead into the
<br />Carter reservoir Of liO,OOf) acre - feet
<br />to supply the St. Vrain river territory.
<br />This reservoir would be west of Bel'.
<br />
<br />thoua. The middle fork would be the
<br />Thompson river, users to be provided
<br />by direct flow who could get 75,000
<br />acre feet a season. The north fork
<br />would lead to the Horse Tooth reser-
<br />voir, a new lake west of Fort Collins
<br />with 96,000 acre feet capacity. From
<br />it Poudre river ditches cculd be sup.
<br />plied upstream as far as the Poud!,f
<br />Valley canal. Study is now being made
<br />of a method for supplying the North
<br />Poudre territory also. Arkins or Buck.
<br />horn reservoir, storage capacity 50,000
<br />acre feet, may later come into the pro-
<br />Ject.
<br />With 482,000 acre feet of new storage
<br />on the western side and 254,000 acre
<br />teet" .of--new..'1Jtorage'-' on" tb~e""eas't.erI.i'
<br />side, northern Colorado farmers. would
<br />always have over a two years' supply
<br />of supplemental water in reserve, suf-
<br />ficient to bril:;lg the supply nearly up to
<br />the 1~~13 total. a year that is taken as
<br />the control year becaUse in 192-6 all
<br />ditches -had all the water they needed.
<br />Comp_ensatory storage for use af
<br />Western Slope would -be eit~er in the
<br />Blue Dr Williams Fork rivers.
<br />Charts Show Irregularity of Supply
<br />Charts showing the irregularity oC
<br />the water supply, its fluctuations by
<br />months, its shortage when needed
<br />most, were shown by Mr. Hansen who
<br />said that some ditches in 1934 were
<br />70 :per cent short. With 736,000 new
<br />acre feet in storage, this situation
<br />would be eliminated, he said.
<br />Figures showing how crop produc.
<br />tion increases with added water. were
<br />given by Mr. Hansen in urging tbe
<br />importance of added water. Produc.
<br />tion of sugar beets alane, he said. in
<br />1926 when sufficient water was avail.
<br />aNe was $31 an acre more than the
<br />sbort water year of -1934, f-igurin.~
<br />beets at only $5 a ton.
<br />Benef-it Large Area
<br />The diverted water would benefit
<br />directly six counties, Boulder, Lari-
<br />mer, Weld, Morgan, Logan, Sedgwick
<br />and a very small part of Washington
<br />county, making the seventh. Popula-
<br />tion is about 2.00,000. Assessed valua-
<br />tion of the six counties has been as
<br />high as $300,000!000, but at present is
<br />held at abaut $200,00'0,0000. There are
<br />around 800,000 acres of highly culti-
<br />vated and irrigated land in the terri-
<br />tory, with private irrigation works
<br />valued at $36,000,000. Crop production
<br />annually in good years is $40,000,000
<br />to $46,000,000. The cities of Boulder,
<br />Longmont,' Loveland, Fort Collins,
<br />Windsor, Eaton, Fort Lupton! Johns-
<br />
<br />town. Fort Morgan, Brush, Sterling,
<br />Julesburg and about 90 smaller towns
<br />are within the area to be served. City
<br />of Denver, only 25 miles from the edge
<br />of the territory, is a city of 800,000 in~
<br />habitants.
<br />
<br />Wat~r Bhortage in this old irrigated
<br />territory is the result of a series of
<br />dry years coupled with the changed
<br />agricultural practices. Earliest works
<br />based their water requirements on
<br />grains and forage crops that de-
<br />veloped, and matured the first half of
<br />the summer season when there _was
<br />the greatest runoff from mountain
<br />snows. Row" c.rops,t ,RX:~S.~"~- s.ugar~".
<br />-beets;""pota:to"es;"oeans and corn have
<br />in large measure supplanted grains
<br />and hay, and are calling for much
<br />greater quantities of water and also
<br />. at a much later period in the growing
<br />season! necessitating larger water sup-
<br />plies and better control of these.
<br />
<br />The following is an info'rmal state..
<br />ment by Porter J. Preston, senior en-
<br />gineer of the U. S. Bureau. of Recla-
<br />mation, who has had direct charge
<br />of the survey of the Colorado-Big
<br />Thompson project:
<br />
<br />THE COLORADO-BIG THOMPSON
<br />PROJECT
<br />
<br />(By Porter J. ~reston)
<br />
<br />This project is for the purpose of
<br />diverting water from the headwaters
<br />of the Colorado River 'at an elevation
<br />of 8050 feet, .about five miles northeast
<br />ot' Granby, through a tunnel under the
<br />Con'tinental Divide 13.1 miles in length
<br />into Wind - River, a tributary of the
<br />Big Thompson, mainly for the supple.
<br />mental irrigation of 800,000 acres of
<br />lands now. receiving an inadequate
<br />water supp-Iy from the St. Vrain and
<br />Little Thompson Creeks, Big Thomp.
<br />son, Poudre and Lower South Platte
<br />Rivers reaching from the foothills
<br />eastward to the viCinity of Julesburg.
<br />
<br />The follOWing are the main features
<br />of the project:
<br />
<br />(1) The Granby Reservoir with a ca-
<br />pacity of 482(000 acre feet and
<br />a surface area of 6764 acres. This
<br />is created by a dam in the Colo.
<br />rado River 220 feet in height and
<br />800 feet in length at the top.
<br />(2) Willow Creek Diversion Canal
<br />diverting the water of Willow
<br />Creek near Dexter into the Gran.
<br />by Reservoir.
<br />(3) The North Fork Diversion Dam.
<br />35 feet in height, located one-
<br />half mile downstream from the
<br />junction of Grand Lake Outlet
<br />with the North Fork of the Co10-
<br />
<br />-'
<br />
<br />rado River. This dam creates
<br />Shadow Mountain Lake covering
<br />1356 acres with water surface
<br />at same elevation as the water
<br />surface of Grand Lake and con.
<br />nected with it through the pres.
<br />ent outlet of Grand Lake.
<br />
<br />(4) A pumping plant located on the
<br />shore of Granby Reservoir with a.
<br />capacity of 870 second feet lift-
<br />ing water to an elevation 10 feet
<br />above the water surface of
<br />Shadow Mountain. and Grand
<br />Lakes. From the pumping plant
<br />the water will floVV" thro~.,.,~a.__
<br />"' ,~'fonF-- .and -."one~h'alf-'"i:iUfe ~~conduit
<br />into Shadow Mountain Lake.
<br />
<br />(5) A tunnel from the easterly end
<br />of Grand Lake running north-
<br />easterly under the Continental
<br />Divide into Wind River, a tribu-
<br />tary of the Big Thompson. The
<br />tunnel is 13.1 miles in length,
<br />9 *,. feet in diameter of hors'e
<br />shoe section: It will carry 550
<br />second feet or 1100 acre -feet per
<br />day~ A wier at Grand Lake and
<br />automatic control gates at en-
<br />trance of tunnel will regulate the.
<br />water entering the tunnel portal
<br />so that the .water surface of
<br />Grand Lak.e can not be drawn be-
<br />low low water stages. .An 800-foot
<br />open channel connects the tunnel
<br />with Grand Lake.
<br />
<br />(6) From the east portal of the tun-
<br />nel a covered conduit will lead-
<br />the water to the easterly slope
<br />of Prospect Mountain, where it
<br />will be dropped 745 feet to gene~
<br />rate electrical pawer at Power
<br />Plant No.!. This plant is located
<br />about o~ne-fourth mile east of
<br />Estes Park ~llage.
<br />
<br />(7) Feeder Canal No.2 will divert
<br />water from the Big Thompson
<br />River immediately below Power
<br />Plant No. 1. This canal win be
<br />10.6 miles in length, fOllowing
<br />parallel with the Big Thampson
<br />River and to the north of it to
<br />near the junction of the North
<br />Fork at Drake where a head of
<br />1286 feet is obtained far Power
<br />Plant No.2. It is planned to use
<br />a maximum of 650 second feet
<br />through this plant.
<br />(8) Feeder Canal No.3, diverting be.
<br />low Power Plant No.2, will carry
<br />water alonp; the north side of
<br />the Big Thompson for a distance
<br />of 2.9 miles to Power Plant No.
<br />3 where a head of 340 feet is
<br />obtained for power development.
<br />It is planned to use a maximum
<br />
<br />l(.LluO
<br />
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