BOARD01406

• Board Meeting Date: 9/27/1999
• Description: ISF Section - Colorado River Basin Issues - Town of Basalt Request for De Minimis Finding - Case No. 5-90CW138
• Board Meetings - Doc Type: Memo

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Under the proposed plan for augmentation, the Applicant can not augment out-of-priority
diversions that may occur to the Roaring Fork River upstream of its confluence with the
Fryingpan River during the non-irrigation season, November through April. Of the
augmented structures, only the Basalt RE-l School District Well will deplete the Roaring
Fork River upstream of the Fryingpan River confluence. The Applicant's engineering
report indicates that 48% of diversions from the Basalt RE-l Well will accrue to the
Roaring Fork River and 52% will accrue to the Fryingpan River. The CWCB staff has
proposed that the Applicant discontinue diversions at the Basalt RE-l School District Well
in September and rely on Basalt Wells 7 through 12 which can be augmented with releases
of water from Ruedi Reservoir. This condition would allow the Applicant to replace their
delayed pumping impacts at RE-l Well in October with historic irrigation season
consumptive use credits from an upstream source and the Board's instream flow water
right would be fully protected.

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The Applicant would prefer to continue diverting at the Basalt RE-l School District Well
through October. This would cause delayed pumping impacts to extend into the month of
November. The Applicant would utilize releases of water stored in Ruedi Reservoir to
augment these out-of-priority diversions and, therefore, the Fryingpan River and the
Roaring Fork River downstream of the Fryingpan River confluence would not be affected.
However, the Applicant estimates that these out-of-priority diversions could deplete a
2000-foot reach of the Roaring Fork River upstream of the Fryingpan River confluence
that could not be augmented with releases of water from Ruedi Reservoir. They also assert
that stream gage information suggests that the CWCB's instream flow water right has
always been exceeded during the month of November (see attached report).

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The unaugmented diversions represent approximately 0.081% of the Board's Roaring Fork
instream flow water right during the month of November. The cumulative impact de
minimis impact to this stream reach in the winter months is currently 0.722%.

The Applicant plans to approach the Board and request that the CWCB authorize its staff
to enter into a pretrial resolution that is fully protective with the exception of allowing a de
minimis impact to a 2000-foot reach of its Roaring Fork River instream flow water right
during the month of November. The Applicant proposes the following language:

"During the month of November, the Applicant will not augment 48% of the
amount and rate of its delayed depletions resulting from October diversion through
the RE-l Well. The CWCB has determined that amount of these delayed
depletions during November are de minimis and the cumulative de minimis
amounts have not been reached within this segment of the Roaring Fork River
during the month of November."

5-90cw138 town of basalt deminimis request board memo

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