PRRIP Governance Committee Meeting and Materials

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1 flows during this period. Late Spring Pulse Flow Period (May/June): As stated previously, improvement of spring pulse events is the Service's highest flow priority (Bowman 1994; Bowman and Carlson 1994). Existing long-term averages for pulse flows are well below Service targets and current projections suggest that below average flow conditions will again occur throughout most of the water year. Although this time period historically experienced elevated flows primarily due to melting mountain snowpack, the Service does not plan to pursue implementation of EA pulse flows in May or June, at this time. Added operational constraints that occur during this late spring pulse period and during the tern and plover nesting season make implementation more difficult. Until new information indicates otherwise, plans are to pursue initial EA pulse tests in the months of February, March, or April. Summer Period (June-September): If drought conditions persist, flows during summer 2008 are expected to be similar to those in 2003 to 2006. If hydrologic conditions improve in the basin making summer flow augmentation practicable as was in WY07, then consideration will be given to again augmenting low flows during the plover and tern nesting season (which continues through August 15) to maintain a better forage base of macroinvertebrates and fish. If rainfall is similar to 2007 amounts, then flows are expected to be similar to 2007 flows. Based on the current hydrologic outlook, EA releases are anticipated during the 2008 nesting season, but ultimately are to be determined by conditions occurring at that time. ! Additional tern and plover nesting sites will be constructed prior to the 2008 nesting season by the Service's Private Lands Program and various partners. An island has been recently constructed at the Dinan tract at Rowe Sanctuary, and another constructed approximately one mile downstream. If weather and flow conditions permit, four additional sites may be constructed prior to the 2008 nesting season. Final plans to augment flows during this period will be based on EA volume, hydrologic conditions, lake levels, conveyance capacity, gainsllosses, District operations, including any hydrocycling plans, presence/absence of nesting terns and plovers, distribution and quantity of forage fish in the area, and availability of suitable riverine foraging habitat. Consideration will be given to the possibility that increased EA releases (i.e., above 400 cfs), if needed, might be possible during this time period due to a reduced delivery rate of irrigation water which could "free-up" additional channel capacity in the channel at North Platte. For planning purposes, approximately 30,000 af of EA release is anticipated for summer flow augmentation. Water Year 2008 EA Carry-Over: Carry-over of EA water &om one water year to the next insures that an adequate amount of EA water will be available for use during the early months of the non-irrigation season before additional water is accumulated or for other purposes during the next water year, especially if EA contributions are at a minimum during the non- irrigation season. At this time, the assessment is that an adequate amount of EA water will be available in WY08 for implementing an initial pulse flow release, augmenting flows during the 49 smnmer period, andlor another yet-to-be-determined release. As the water year progresses, habitat, species, and hydrologic conditions, EA volume, seepage/evaporation losses, and releases, and lake levels will be closely monitored to determine how much EA water can or should be Water Year 2008 EA AOP 11 October 15, 2007