WSP07035

• File Number: 8509
• Description: San Luis Valley
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 12/1/1969
• Title: Irrigation Water Management Study of the San Luis Valley Colorado - PART 1 of 2
• Water Supply Pro - Doc Type: Report/Study

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Other Tributaries

Other smaller tributaries in need of channel restoration work
are La Jara, Alarrosa, and Rock Creeks... The reach of channel
restoration for La Jara Creek would be its 18 river miles fran
u. S. Highway 285 to the Rio Grande, with a restored channel
length of 14.3 miles. I\brk on Alarrosa Creek would extend for
11 miles from U. S. Highway 285 to the Rio Grande. The length
of channel restoration for :!bck Creek is 21. 7 miles fran its
intersection with the Bowen Drain to the Rio Grande. The
restored channel length would be about 13.5 miles. The plan
for :!bck Creek would also include the rehabilitation of the
Bowen Drain fran :!bck Creek to the Rio Grande because that
drain is essentially a part of the :!bck Creek systen....

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The est.irnated cost of channel restoration for the three
streams is $2,260,000.

Costs and Benefi ts

The est.irnated construction cost for restoration of the five
tributary channels is $6,279,000. The est.irnated annual opera-
tion, maintenance, and replacerrent costs amount to $82,000.
This channel work would result in an average annual reduction
in water losses of 12,000 acre-feet. The project would be
economically feasible with a benefit-cost ratio of 2.34 to 1.

The Davis Engineering Service Report 1/ states that the Rio Grande
Water Conservation District at a neetI'ng held July 8, 1968 established
the follcwing priori ties for channelization projects:

Channelization of three to four miles of the San Antonio River.

Charmelization of approximately 15 to 20 miles of the Rio Grande
from Alarrosa southward beyond its confluence with the Conejos
River.

The follcwing projects were not assigned a priority:

Channelization of Rio Grande above Alarrosa, possibly to
Seven Mile Plaza.

Channelization of Alarrosa and La Jara Creeks into the Rio
Grande.

In surrrnary, the significant i tern in the Bureau of Reclamation's
report relating to improving drainage outlets is that "the river
channels would not be deepened because they could then act as major

11 See reference 5.

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