Summary Table of Credits and Lease Payments for 2007

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Analysis Flowchart for Colorado PRRIP (Platte River Recovery Implementation Program) Water Accounting spreadsheet Jan. 15, 2006 For PRRIP, Colorado has water development/retiming obligations under two separate tasks -- Tamarack 1 and CPFD. Tamarack 1 (Tam 1) is Colorado's Initial Water Project described in the PPRIP Water Plan Attachment 5 Section 3, pages 26 -35. CPFD is Colorado's Plan for Future Depletions described in the PRRIP Water Plan Attachment 5 Section 9, pages 263 -271. The PRRIP Water Plan is available from http: / /www.platteriver.orgi library/ program _document /water_ plan _final.pdf The basic process for Tam 1 is diverting water to groundwater recharge during times of excess to target flows at Grand Island and retiming that water through delayed groundwater returns /accretions into times of shortage at Grand Island. The basic process for CPFD is diverting to groundwater recharge excess waters resulting from Colorado population growth and retime that water through delayed groundwater returns /accretions into times of deficit (May and June) under CPFD. A separate spreadsheet approved by PRRIP computes the accretions and deficits resulting from Colorado population growth since July 1, 1997 and the mix of water sources used to meet the water needs of the increased population. The recharge and retiming for Tam 1 and CPFD is currently done at the CDOW Tamarack Ranch SWA (SPWRAP pays electricity and gets water credits - -no lease) and thru leases from decreed augmentation /recharge plans in the lower SP River. Definition 1: Net Recharge at a pond structure is gross diversions to the pond minus net pond evaporation. Definition 2: Accretion is lagged groundwater return flows at the river resulting from Net Recharge as determined by AWAS groundwater model. AWAS (Alluvial Water Accounting System) groundwater model uses Glover alluvial aquifer parameters and model developed /maintained by CSU -IDS and available at http://www.ids.colostate.edu/index.html?/projects/splattel An important point is that two separate parallel analysis are done to determine credits for Tamarack 1 and CPFD. Some of the same acre -feet of net recharge are input for both analysis but on the output side where credits for Colorado's PRRIP are determined, the credits for Tam 1 and CPFD are in separate months with no overlap in a given month. Net Recharge for each Plan by month (Total and by each recharge pond) for 2003- 2007 CPFD ANALYSIS TAM 1 ANALYSIS nlhly net recharge Excess credits in lower river in a % days of Excess flow for month at a Plan not used in No month from CPFD analysis of USGS river gage Grand Island, NE No 3lysis for accretion population increases and water compared to USFWS target flows dil in CPFD sources with buffer for gage inaccuracies (ie, icing) Yes Yes Reduce by winter evap and subtract Multiply each Plan's net recharge by any dedicated net recharge done at structure and month by % monthly CDOW Tamarack Ranch Stale excess at Grand island Wildlife Area Prorate amount to each Plan by Import all Plan's net rech Plan's % of total recharge for all Tam 1 into AWAS Tam 1 plans starting with plans at the groundwater model Staleline and not to exceed each Plans total net recharge all Plan's net recharge for AWAS output of 2007 months into AWAS CPFD 1 accretions for each Plan to /wafer model RESULTS page output of 2007 monthly Multiply by monthly % of days that accretions for each Plan to accretions occur below last river -TS page drying diversion as determined by river call and consider Western Multiply by monthly % of days that Multiply by % monthly shortage at accretions occur below last river Grand Island with +10% buffer on drying diversion as determined by gage Flows THLY CREDIT for CPFD from { (MONTHLY CREDIT for Taml from Plan (Multiplied by $40 /af in I each Plan (Multiplied by $40 1af in for lease payment) 2007 for lease payment) a Plan not used in rlysis for accretion dil in Tam 1