PUB00068

• Year: 1952
• Title: A Hundred Years of Irrigatioin in Colorado, 100 Years of Organized and Continuous Irrigation
• Author: CWCB
• Description: Irrigation history of Colorado
• Publications - Doc Type: Historical

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-57..

The Importance of Return FloH to Colorado Irr2:gat~

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R. L. Parshall
Retired Irrigation Engineer
Colorado A & M College and Soil
Conservation Service, U.S.D.A.

We are on this occasion commemorating a historic event. One hun-
dred years ago, a colony of settlers established themselves in the
fertile valley of the Culebra at San Luis and having had experience in
the art of irrigation recognized the necessity and advantage of divert-
ing Hater into an artificial channel to irrigate the land bordering the
north side of this sparkling mountain stream. Spanish laHs and customs
came Hith this group of settlers from the South and the simple diversion
of Hater from the Culebra into the People I s Ditch established a claim of
legal stat.us in accordance 'With the recognized l<l_H of right and pro-
cedure, as of April 10, 1852. (Centuries of irrigation in Spain gave
these people a background on which .to' draw.)

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Previous speakers on the program of this centennial celebration
have reviewed the historical events and the development of the use of
water to sustain the settlements of the pioneers. In this development
of use of water for irrigation, as guided by the limitations of law and
order,. related problems of agriculture have appeared requiring the at-
tention of the agricultural scientist and the engineer.

The fundamental principle of Colorado irrigation law is first in
use, first in right, but the water must be applied beneficially. Other
appropriators follow in time, diverting from a common water supply, and
in due course the flow of the stream is insufficient to provide amply
for all ditches served by the parent stream. vie here recognize the
problem of limitation of water supply where the solution, in part, re-
quires the attention of the engineer, agronomist, soil scientist, and
others.

Almost from the beginning of irrigated agriculture in our State
the menace of water shortage in many areas has been acute. Relief has
been found in the storage of excess water during high stages of flood
flow together with the impounding of stream flow during periods when the
water is not needed for direct irrigation. This reserve water supply
later to be used to augment the needs of appropriators having a late
right to direct flow water for their lands.

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The subject proposed for discussion, as appears on the program, has
to do with the. all-important question of water supply. In the past many
engineers, not thoroughly informed as to the potential water supply of
natural streams, have in many cases neglected this limitation. As a
result they have helped to create water shortages for the irrigation
enterprises. In this picture is found a compensating factor in the
phenomenon of return flow or seepage into the stream from adjacent irri-
gated lands and the ccntribution from storage reservoirs located within
the drainage basin.

In northern Colorado along the various tributaries to the South