WSP01353

• File Number: 8441.400.20
• Description: Colorado Big Thompson Project - Reports
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 6/1/1952
• Author: US DOI/BOR
• Title: Colorado-Big Thompson Project -- Definite Plan Report -- Volume 1
• Water Supply Pro - Doc Type: Definite Plan Report

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Primary Are~
Supplemental water supply ~acres) . . . . . . . .
Payment capacity per acre . . . . .
O&M and replacement/ac/yr . . . . . . . . .

Amortization capacity/ac/yr . . . . .

Secondary AreaS!
Supplemental water supply (acres) . . . . . . .. 230,000
Payment capacity per acre . . . . . . . . . . .. $4.29
Amortization capacity/ac/yr . . . . . . No monetary return

COLORADO-BIG THOMPSON PROJECT

SllIillllary Sheets

BENEFIT-COST RATIO

Annual Benefits
Annual Costs

IRRIGATION

$16,256,000
= -$0,732,000

=

2.4:1

'-,,{

Total or
Average

. .

283,000
$5.04
.77
$4.27

. .

. .

. .

Repayment period - irrigation costs . . . . . . . . 40 years
Farm Units: At present, approximately 5,600 farms. Average
farm size in the "primary" area is 160 acres.
Average farm size in the "secondary" area varies
from 125 acres in the vicinity of Julesburg to
300 acres north of Sterling. Very few new farm
units are anticipated.

Growing Season. . . .. . . " . . . .
Elevation of project area. . . . . .
First water available . . . . . . .
All project lands to be irrigated. .

. . . . "

. It . .

. . .

. .

146 days
4,500 msl
June 23, 1947
July 1, 1953

y There are 477,000 acres of irrigated land in the "primary"
area. The supplemental water supply is adequate to reduce the average
shortage to a tolerable supply on 283,000 acres through the first use
of project water. Return flows make water available and create
benefits over a larger area. However, payment capacity is computed
only for area of first use where 'the amount of project water
delivered may be identified.
BI'Essentially only. return flows from the first use of project
water will be made available to the "secondary" area. Studies indicate
that approximately 34% of historical shortages in this "secopdary" area
will be alleviated through return flows from project water. No
amortization capacity is computed since proj ect return flows are not
identifiable and are considered only as a part of the natural flow
of a stream subj ect to appropriation.

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