Summary Table of Credits and Lease Payments for 2007

• Description: PRRIP
• State: CO
• State: NE
• State: WY
• Basin: South Platte
• Water Division: 1
• Author: SPWRAP
• Title: Explanation of Computations, Inputs, and Results for Colorado PRRIP Depletion Plan
• Water Supply Pro - Doc Type: Budget

Section E: % days in a month of river call including S. Platte Compact call above the
Harmony #1 Ditch in Colorado. River call in Colorado represents a ditch that diverts the
entire river. Water for credit for Tamarack 1 and CPFD in 2007 accrues to the river
below the last diversion in Colorado that diverts the entire river and when no SP Compact
call (i.e., excess to well augmentation at the Stateline). This % days is used to compute
the amount of groundwater accretion water in a month accruing above the Harmony #1
that is not diverted by the Harmony #1 Ditch when no SP Compact call.
Section F: % days in a month of river call including SP Compact call below the
Harmony #1 Ditch in Colorado. This % days is used to compute the amount of
groundwater accretion water in a month accruing below the Harmony #1 that is not
entirely diverted by other Colorado ditches and when no SP Compact call. The Western
Canal just over the Stateline in Nebraska on the S. Platte is also considered when
determining credits for Tamarack 1 —the Western must also not be diverting the entire
river during months of credit for Tamarack 1 and this did not occur in 2007 as seen by
comparing Stateline river flows at the Julesburg gage to Western Canal diversions.
The five existing augmentation plans developing water for credit in Tamarack 1 and
CPFD are those plans nearest the Stateline in order to minimize canal interception in
Colorado. These plans are the Lower South Platte -LSP, Sedgwick County Well Users -
SCWU, Dinsdale, Condon and Lower Logan Well Users -LLWU. LSP, SCWU,
Dinsdale, and Condon are all located below the Harmony 91 Ditch while LLWU is both
above and below the Harmony 41. There is a page in the < Colorado PRRIP Water
Accounting> spreadsheet for each of these plans where the net recharge inputs for each of
these plans is inserted in Column A; inserted are both the total net recharge by the plan
and the individual net recharge by each recharge structure. The inserted data is monthly
for the years of 2003 through 2007. These years were selected for analysis because these
years had the greatest new development of recharge sites. In Columns P (for Tamarack
1) and Column AE (for CPFD) of these pages for each plan is where the water creditable
to each plan for Tamarack 1 and CPFD is distributed to each plans recharge structures.
This distribution for Tamarack 1 is based on the % monthly excess of Section A on the
Setup page. This distribution for CPFD is based on the CPFD net positive accretions in
Section B (reduced by the net recharge at the CDOW Tamarack SWA) of the Setup page
distributed prorata among the four plans below Harmony #1 with any remaining CPFD
distributed to LLWU.
The creditable diversions for each plan by recharge structure for Tamarack 1 and CPFD
computed on each of these individual plan pages of the spreadsheet is copied to the page
in the spreadsheet called "AWAS input_5 plans ". Data from this page is then saved to a
tab- delimited text file for import to two AWAS models (one model for Tam 1 and one
model for CPFD). The AWAS model computes the retimed accretions to the river that
can be credited as replacement of shortages at Grand Island for Tamarack 1 and credited
as replacing the May and June deficits resulting from the CPFD. The output from the
two AWAS models is copied into the page of the spreadsheet called "RESULTS ". The
RESULTS page computes the creditable accretions for Tamarack 1 during times of
shortage (based on Section D of Setup page) and below the last drying diversion for each
plan. The Results page computes the creditable accretions for CPFD below the last river
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