PROJ00207

• Contract/PO #: FS0020X
• Contractor Name: Paonia, Town of
• Contract Type: Loan
• Water District: 0
• County: Delta
• Loan Projects - Doc Type: Feasibility Study

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Feasibility Report for Improvement of Paonia's Water Supply System
Town of Paonia
April 21, 2000

review, anomalous data points were deleted from the data to provide a more realistic monthly
average,

W estW ater performed a comparative regression analysis of average monthly stream flow data
and treatment plant inflows, As a result of the analysis, WestWater found that if the monthly
average treatment plant inflows were lagged by one month to reflect a reasonable aquifer lag
time for the Town's springs, there was a very good correlation between stream flow data and
treatment plant inflows, This regression analysis is summarized on Figure 5,5. Good
correlations were also found between snowpack data and stream flow data and between
snowpack data and treatment plant inflows data,

The next step was to review the stream flow data to find a representative dry period for use in
the firm yield analysis, WestWater reviewed the available stream flow records at the Somerset
gage on the North Fork of the Gunnison and determined that the years 1989 and 1990 resulted
in the driest consecutive 2-year drought in the data since 1934, These years also represented the
time when the Town had the most difficult time supplying water to its customers. It was during
this period that Town personnel reported that all of the treated water storage tanks were nearly
drained during the hottest months of the summer ofl989, As a result, the 1989-1990 record was
used with the previously developed correlation equations to predict inflows to the treatment plant
during this critical period, This predicted dry period inflow is shown relative to predicted wet
year and average year inflows on Figure 5.6. The average annual inflow during this 2-year
period is estimated to be 623 acre-feet per year or about 203 million gallons per year, The
estimated value of 623 acre-feet compared favorably with the 1989-90 State Engineer's diversion
records, which showed an average diversion of645 acre-feet during this period, It is our opinion
that this represents a reasonable estimate of the Town's firm yield, Better data could provide a
better estimate, but the firm yield of 623 acre-feet was judged to be acceptable for this level of
study,

J.\PROJECTS\99368\Reporu\FcasibiliIY. wpd

<v. GEl Consultants, Inc.

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