7750

• UCREFRP Catalog Number: 7750
• Author: U.S. Bureau of Reclamation.
• Title: Study of Alternative Water Supplies for Endangered Fishes in the "15-Mile Reach" of the Colorado River.
• USFW Year: 1992.
• USFW - Doc Type: \
• Copyright Material: NO

CHAPTER III GAINS ALONG THE REACH
Table 1
Estimated return flows from irrigation practices along the Reach
Acres Lateral Canal On-farm Deep Tail
Irrigation system served seepage seepage seepage perc water
East End Government Highline 1,950 1,380 4,620 900 1,490 3,810
Price Ditch 3,700 2,270 1,150 1,880 2,840 7,030
Stubb Ditch 900 230 610 460 690 1,710
East GVIC Mainline 4,400 1,520 5,220 2,860 4,560 6,490
Orchard Mesa Ditch No.. 1 2,700 930 1,170 760 1,710 9,210
Orchard Mesa Ditch No. 2 2,600 340 500 710 1,570 6,080
The above volumes were converted to a flow rate by dividing the volume into a 200-day irrigation season and are
presented below.
Table 2
Estimated equivalent return flows (cfs)
Lateral Canal On-farm Deep Tail-
Irrigation system seepage seepage seepage perc water
East End Government Highline
Price Ditch
Stubb Ditch
East GVIC Mainline
Orchard Mesa Ditch No. 1
Orchard Mesa Ditch No. 2
Returned uniformly along the
Reach
3.5 11.6 2.3 3.8 9.6
5.7 2.9 4.7 7.2 17.7
0.6 1.5 1.2 1.7 4.3
3.8 13.2 7.2 11.5 16.4
2.2 2.9 1.9 4.3 15.6
0.9 1.2 1.7 3.7 13.0
Total 16.7 33.4 19.0 32.2 76.6
16.7 33.4 19.0 32.2 57.3
Total returned by the end of the Reach 160
Notes:
1) Acreages were taken from the Grand Valley Unit sizing files.
2) The values for on-farm ditch seepage, deep perc, canal seepage, and lateral seepage were taken from the
Grand Valley Verification Memo Technical Supporting Data, April 1986, p. VII-15.
3) On-farm irrigation efficiency is 43 %, Ibid. p. VI-18.
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