HydrologyWellAugmentationInSP

• File Number: 8420.500
• Description: South Platte River Basin Task Force
• State: CO
• Basin: South Platte
• Date: 8/1/2007
• Author: Charles F. Leaf
• Title: Review Draft Report Submitted to SPTF
• Water Supply Pro - Doc Type: Report/Study

worth referring to Glover (1975) again who found that
it takes but a few years of lead time to establish river
regimen, and at the end of this ShOli period, "... a new
regimen will have been established and what took place
before will have minor importance..."

The PRBWBM, which has been extensively calibrated
and validated in this study and in Leaf, 1999, supports
Glover's conclusions. The simple lagging algorithms
shown in Figure 5 correctly simulate overall river be-
havior with reasonable statistical accuracy as shown by
the error analyses in Appendix 1.

Since what took place in the river three (or fewer) years
earlier has minor significance today, it is gross error to
carry forward by mathematically complex uncalibrated
and unvalidated lagging procedures, fictitious depletions
from wells that began pumping more than 50 years ago.

Figure 8 - Replacement Water Requirements vs.
Number of Wells in Augmentation Plan

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CENTR L WAS

LOWER PLATTE
& BEAVER

NUMBER OF WELLS IN PLAN

10

100

1000

Figure 7
Simulated Replacement Water Requirement Frequency Curves for
1975 - 1994 Record Period in the Kersey-Julesburg Reach of the South Platte River

200

100
90
80
70
60
50

RECURRENCE INTERVAL (yrs.)

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III
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....
-

40

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30

20

10
9
8
7
6
5

4

3

1935 (assuming that all
wells were in existance)

.

Note: The.... symbol above is the level
replacement required by objectors
to "restore" the River for all wells
that existed in 2002.

PROBABILITY (percent)
1 2 5 10 20 30 40 50 60 70 80 90 95 98 99

999

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