WSP05216

• File Number: 8441
• Description: Colorado Big Thompson Project
• Basin: South Platte
• Water Division: 1
• Date: 10/1/1936
• Title: Water Resources - Colorado's Greatest Wealth - The Colorado-Big Thompson Water Tunnel Plan Would Aid Vast Area Thru Its Preventing Frequent Shortages
• Water Supply Pro - Doc Type: Publication

of 650 second feet through this
plant.
(9) Carter Lake Diversion Canal will
divert immediately below Power
Plant No. 8 on the south side
of the Tiver and at a point about
5.5 miles down stream will be
bifurcate, one branch leading
southward and discharging into
Carter Lake Reservoir. The oth~
er branch going easterly will con-
vey water to Power Plant No.4.
Its total length from the river
diversion is 4.8 miles. This power
plant will have units operating
under two different neads of 390
and 558 feet, respectively. The
water froIn" the, f()rttl~r wjU~cross~,
,- 'tIHf river;' dfschaigj:ng. into the
Horsetooth Reservoir Feeder and
the latter into the BiK Thompson
River.
(10) Carter Lake' Reservoir, south~
west of Loveland, with a -capacity
of 110,000 acre feet, will store
water .for the St. Vrain, Little
and Big Thompson sector of the
project.
(11) Horsetooth Reservoir, southwest
of Fort Collins, with a ca.pacity
of 96,000 acre feet, will store
water for the poudre sector of
the project.
(12) Arkins Reservoir, northwest of
Loveland with a capacity of 60,-
000 acre feet, will store water
for distribution along the Big
Thompson or the lower South
Platte River section. Water may
also be distributed to the South
Platte from either (he Carter
Lake or Horsetooth Reservoirs.
(18) Outlet canals lead from these
three reservoirs to the several
streams which each is to supply,
of sufficient capacity to empty
the reservoirs in from 60 to 70
days.
(14) The Green Mountain Reservoir,
south of Kremmling, is planned
for developing to a sufficient
capacity to replace water taken
from the Colorado River at or
above the Gra~by Reservoir that
would be usable for irrigation
from the main river westward to
tbe Colorado-Utah state line. This
reservoir can be developed to a
capacity of 152,000 acre feet. One
power plant may be developed
immediately below the reservoir
dam and a second plant about
two miles down stream.
(15) A transmisson line conecting the
several power plants with the
pumping plant at Granby and tie~

ing into the power lines of exist-
ing public utilities in northeast.
ern Colorado.
(16) A study is being made to de~
termine whether there is a suf-
ficient water supply to justify
the development of the Ranch
Creek Reservoir, feeder canal
from Frazier River and connect-
ing canal to Granby Reservoir.
This is considered as a secondary
development for irrigation of
lands below Granby Reservoir and
above KremmIing. It may be used
in part to supplement the water
supply of the Granby Reservoir.

. P.l~IJ.,,__of.. Dcy,eJo.pment" >and-...Operatton
The initial development will include
the construction of the following:
Granby Reservoir, Willow Creek Di-
version Canal, North Fork Diversion
Dam, Pumping Plant and conduit. to
Shadow Mountain Lake; Continental
Tunnel, Conduit from East Portal of
tunnel to Power Plant No.1, Power
Plant No: 1, Oarter Lake Diversion
Canal, Carter Lake, Horsetooth and
Arkins Reservoirs, with feeder and
outlet canals, Green Mountain Reser-
voir and transmission line connecting
Power Plant No. 1 with the Pumping
Plant and a connection with existing
transmission lines.
It is estimated that these works will
deliver 300,000 acre feet annually from
the Colorado River Basin to the east-
ern slope without encroachment. upon
the rights of usage of water for bene-
ficial use in the COlorado River Basin
in the State of Colorado.
Grand ,Lake L.evel Constant
The present water level of Grand
Lake will not be changed but on the
contrary the water surface will be
held to a more uniform level than is
now attained under natural conditions.
The project will be operated to store
the major portion of the flood season's
flow of the Colorado River and other
gathering agencies in the Granby Res-
ervoir, thence by pumping the water
back into the Shadow Mountain Reser-
voir for discharge through the Conti-
nental Tunnel during the late summer,
fall, winter and spring, at a uniform
rate for the development of power.
It will be restored in Carter Lake,
Horsetooth and Arkins Reservoirs for
use mainly during July 10 to Septem-
ber 25 for the: irrigation of late matur-
ing crops. The canals leading from the
three reservoirs on the eastern slope
are planned of ,sufficient capacity to
deliver the 300,000 acre feet in 60 to
n days, as required by the late crops.

The project has the advantage with
its storage capacity of nearly three.
quarter million acre feet on both sides
of the Continental Divide to equalize
the years of eXcessive runoff with the
years of low flow, to transfer the
water at a rate that a small sized tun-
nel can be made to serve the purpose,
giving a uniform. water flow for the
development of firm. power, and hav.
ing the stored water on hand at the
time of spring seeding so the farmer
may sow with some assurance that he
will have water for irrigation.

Although cost figures on the plans
as. ._I1~!V.,,4~,yeJ().P.e.d ara,..not."y.et--avail~
- able, there seems to be no doubt that
the cost of the water will be well with-
in what the farmer can pay when its
economic value is considered in matur-
ing, the late crops of the territory to
be served.

Organization

Before construction of the project
can be started, it will be necessary.
to have an organization perfected that

can represent the interests of North-
ern Colorado for the purpose of con~
tracting with the United States
Government, securing the repayment
of the cost and operating the complet-
ed system.
The preliminary work is being done
by The Northern Colorado Water Us-
ers Association, a mutual stock com.
pany similar in legal form to the ordi-
nary ditch organization in Colorado.
While this company was incorpo-
rated with the idea of uSing it as the
permanent agency for the purpose,
several other plans are .bein,g ,stu1iie,d.
~in.,(}rder"-to 'oo-gure"'tha:t Uie 'Dest" :ODs.'
sible type of organization is secured.
Among these plans is one for a form
of improvement district which would
include powers of appraisal of bene~
fits to property within the district and
the levying of taxes. Such a plan would
provide means for distributing some
of the costs of the project to property
indirectly benefitted and would allow
a wider base and more equitable dis-
tribution of as:sessme~~ Zl. 1'0 0

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