9674

• UCREFRP Catalog Number: 9674
• Author: Endangered Fish Flow and Colorado River Compact Water Development Workgroup.
• Title: Final Report - Colorado River Compact Water Development Projection.
• USFW Year: 1995.
• USFW - Doc Type: \
• Copyright Material: NO

COLORADO RPVER COMPACT WATER DEVELOPMENT PROJECTION
November 2, 1995 FINAL REPORT
Page 15
with interested parties in each basin to refine the development allowance and identify the
portions of the recovery instream water right which will be classified as pazagraph 3 and 4.
VII. WORKGROUP OBSERVATIONS AND RECOMMENDATIONS TO THE
CWCB
The Workgroup's recommended approach for distributing Colorado's remaining
compact apportionment among the major tributazies is described in Table 4. In reviewing
Table 4, the Workgroup wishes to emphasize the following observations:
A. We have not recommended any specific distribution to any particulaz subbasin; nor
have we specifically recognized any particular water rights. Rather, we have established a
recommended range of development allowance for each subbasin as described in Table 4.
The upper limit of these ranges allows upto 3.855 MAF of total consumption from the
Colorado River Basin by distributing up to one-half of the remaining compact apportioned
waters needed to reach the 3.079 MAF level of development to each of the seven major
subbasins but only to the extent that water is physically available for appropriation. The
lower limit of our recommended ranges is based upon the lower estimate of Colorado's
apportionment (i.e., 3.079 MAF), and distributes the state's approximately 450,000 acre feet
of remaining apportionment among the seven major subbasins based on the proportionate
share which each subbasin contributes to the natural flow of the Colorado River originating
within Colorado but, again, only to the extent that water is physically available for
appropriation. These ranges, which aze shown in columns (G) and (I~ of Table 4, should
provide the flexibility for full compact development to occur as it normally would under state
water law and assure that future development opportunities in Colorado aze constrained by
Colorado's compact apportionment rather than the instream flow water rights.
B. Colorado's compact apportionment is dependent on both the long term water
supply and the assumptions made concerning the Law of the Colorado River. There are
varying assumptions relating to water supply and the Upper Basin states' obligation to meet
one-half of the Mexican Treaty commitment, which result in consumptive use apportionment
values for Colorado ranging between 3.079 MAF and 3.855 MAF. As a result, a range of
development allowance opportunities for each of the seven subbasins is recommended.
C. A conservative assumption should be made in which all future water development
may occur under water rights which will be junior in priority to the endangered fish recovery
instream flow water rights. There aze numerous decreed conditional water rights with the
combined capability to more than fully develop Colorado's remaining compact apportionment,
and we recognize that future development of Colorado's remaining compact apportionment
will most likely reflect a combination of both new water rights and the development of senior
conditional water rights. In many cases, the water rights developed may be relying on the
ability to reuse water which has previously been used. The recommended approach is
intended to provide a safety factor sufficient to allow water rights junior to the anticipated
instream flow water rights to fully utilize the remainder of Colorado's apportionment.
D. The development of senior conditional water rights should not be impaired by a