Letter Regarding Cumulative Effect Report for Colorado's Plan for Future Depletions

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has not increased as much as water conservation and that is due to reuse already being at higher percent values for the initial assumptions because reuse activities were already in place initially. The revised % mix of water sources listed in Table 1 B and the revised 0.2504 ac- ft/person/year gross per capita use are copied to the CPFD analysis spreadsheet for the determination of the accretive /depletive effect of each water source and the cumulative effect downstream at the Colorado- Nebraska Stateline. Retiming through managed groundwater recharge projects the monthly net accretive effects mitigates net depletive effects in a month. Figures IA, 1B, 1C and 1D utilized the revised assumptions and show the monthly accretive /depletive effects of each water source and cumulative effect at the Stateline for 2007, 2008, 2009 and 2013 respectively. Figure I for 2007 shows the depletive effect in May and June total 1,564 acre -feet, while Figure I for 2008 shows the depletive effect in May and June total 1,720 acre -feet with the average of these depletive values for 2007 and 2008 of 1,642 acre -feet. From Figures 1 A and I B, the average accretion total for October through April on a calendar year (Jan -Dec) basis is 21,894 acre -feet (20,851 in 2007 and 22,936 in 2008). These accretions are retimed through managed groundwater recharge projects so some of the lagged groundwater return flows from this recharge can reach the river to replace the May and June CPFD depletions. For the beginning year 2009 and ending year 2013 of the next 5 -year reporting period, Figure IC for 2009 and Figure I D for 2013 list the total May/June depletive effect from the CPFD analysis as 1,861 acre -feet and 2,366 acre -feet respectively. Mitigation of Depletive Effects Colorado in conjunction with the SPWRAP organization has developed managed groundwater recharge projects in the lower South Platte River in Colorado for both mitigating the depletive effects of Colorado's Plan for Future Depletions and developing Colorado's Initial Water Project (Tamarack I)_ Projects have involved new development such as the Tamarack Recharge Project on the Colorado Division of Wildlife's Tamarack Ranch State Wildlife Area -SWA near Crook Colorado and the Feyborne recharge project with a private landowner near Ovid, Colorado. The Tamarack SWA recharge project was begun in 1996 and currently has 10 recharge wells with 7 more planned. The Tamarack SWA recharge project was constructed mainly with State of Colorado funds. SPWRAP has an agreement with the State of Colorado where SPWRAP will pay all the operations and maintenance costs for the Tamarack SWA recharge project. Electrical pumping costs for the recharge wells at Tamarack was $29,716 for winter 2007, $99,784 for winter 2008, and $76,480 so far for winter 2009 for December 2008 through February 2009 with recharge well pumping at Tamarack SWA also in the months of March and April 2009. The just constructed Heyborne recharge project has a floating pump lift station in a river slough and has begun pumping this spring of 2009. The Heyborne recharge projects was funded by SPWRAP, State of Colorado and Ducks Unlimited where SPWRAP will pay all the operations and maintenance costs and in return receive credits for Colorado's PRRIP water obligations at no other cost. Other recharge projects in the lower river are also planned through this funding partnership. A major aspect of SPWRAP's water development for Colorado's PRRIP water credit is the partnering with other recharge groups in the lower South Platte River Basin in Colorado that utilized managed groundwater recharge for their own well augmentation plans. These augmentation plans have excess water not needed for well augmentation and SPWRAP pays (i.e. for 2007, 2008 and 2009, the rate is $40 per acre -foot) on an annual basis for water not needed by the plans and which can be credited for depletion mitigation in the CPFD (or in Colorado's Initial Water Project, Tamarack I). These payments are made after the credit for Colorado's PRRIP water obligations have occurred which typically will be in July. In the winter of 2008 -2009, SPWRAP started a new payment program with these other recharge groups and that is the payment of recharge wells' electrical operating expenses plus 5% during November through January. This assists entities with ongoing costs upfront rather than these entities getting payments in arrears up to 6 months later. For these payments, SPWRAP receives the water credits for Colorado's PRRIP water obligations (i.e., water credits for both CPFD depletion replacement in May and June and credits for Colorado's Initial Water Project- Tamarack I) at no additional cost. SPWRAP plans to continue both these payment programs in the future in order to allow maximum flexibility in working with other recharge groups /augmentation plans in the lower river in Colorado. The augmentation plans/recharge groups that SPWRAP is currently working with are (starting upstream near Sterling and moving downstream to Julesburg): (1) the Lower Logan Well Users with their groundwater recharge through the Bravo, Iliff & Platte Valley and Harmony 92 ditches and ponds and through recharge wells (i.e., wells next to the river which pump through pipelines to infiltration ponds farther from the river); (2) Condon Ranch with their groundwater recharge through recharge wells; (3) Dinsdale Brothers with their groundwater recharge through recharge wells; (4) Sedgwick County Well Users with their groundwater recharge through the Petersen, Settlers, Highline and South Reservation ditches and ponds and through recharge wells; and (5) Lower South Platte Julesburg Well Users with their groundwater recharge through the Petersen and Liddle ditches and ponds and through recharge