WSPC00539

• File Number: 8530.300
• Description: Rio Grande Basin-Water User Groups and Conservancy Districts-Rio Grande Water Conservation District
• State: CO
• Basin: Rio Grande
• Water Division: 3
• Date: 7/20/1970
• Title: WCD-Rio Grande Water Conservation District-Corres Reports etc-1967-82-Preliminary Engineering Report for the Rio Grande Water Conservation District
• Water Supply Pro - Doc Type: Report/Study

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him to administer the rivers so as to assure snnual compliance
with Compact schedules. Stricter administration of the waters
was started in 1968. Aided by the cooperation, and in many cases,
the sacrifices of the Colorado water users the schedules for
delivery of ",atar ut the Lobatos gaging station were met in 1968
and 1969.

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Due to inability to control the rivers it was found that to assure
Compact deliveries at the Lobatos gaging station an overdelivery
of some magnitude would be the usual result. As a result of this
situation overdcliveries of approximately 21,000 and 64,000 acre
feet were JIIade in 1968 and 1969, respectively.

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In 1968, on the basis of the State Engineer's estimate of anti-
cipated runoff, it was determined that during the period of
peak flows approximately 33% of the Rio Grande and approdmatsly
35% of the Conejos River would need to be delivsred to New Mexico
to comply with the Compact requirements. Both rivers were admini-
stered, in relation to permissible diversions, as though the Compact
were the number one decree. All actual decrees were permitted to
divcrt, in order of decree priority, only to the limit of the volume
of water in the rivers in excess of the water required by the
Compact schedules.

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In 1969, aud it appears 1970, administrative experience aided by
cooperation of the San Luis Valley water users, has permitted total
use of the rivers during the 60 day irrigation season. In return
the wutcr of the rivers and their tributaries below the various
reservoirs and the total return flow are delivered to the Lobatos
gaging station for credit as Compact delivery from November to
April, if necessary, to meet the schedules. Storage is permitted
in precompact reservoirs as in the past, except intermittent
storage is permitted during the irrigation season when the volume
of water flowing in the rivers e~ceeda the demand required to
satisfy decreed surface rights.

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STATEMENT OF THE PROBLEM

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The effect of the decision to administer the rivers in the manner
described above has been the denial of water to appropriators who
formerly may have been permitted to divert, This is water which
had been decreed to them by the State of Colorado prior to ratification
of the Compact in 1939, water which even until 1968 had not been
denied thcm. The belicf that waters of the Rio Grande and Conejos
Hiver would be available to the San Luis Valley water users stemmed
from the long held supposition, shared by most of these watar users,
that such water would be available to supply sven junior decrees.

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