EAC/RCC WY 2002 Spring Meeting Minutes

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those years, whereas, below average conditions have preceded 2002. As a result, the impact of this year's low snowpack will probably be more significant. Kerkman provided a summary of CNPPID Maintenance Activities. He reported operational flow requirements were suspended at CNPPID's diversion dam from Oct. 4, 2001, to March 8, 2002, due to the rehabilitation of the J-2 hydro plant. They were suspended again from March 28 to April 1 for partial repair of the concrete apron below the J-2 hydro plant. He reported that Kingsley hydro would be offline from April 22 to Apri126 for annual inspection and maintenance which will limit releases, including EA releases if requested, to what which can go through the bypass. CNPPID plans to rehabilitate Jeffery and J-1 hydro plants during the fall and winter of 2002 but anticipate they will be able to meet minimum diversion requirements and accommodate EA releases, if requested, during the majority of those activities. A four-day outage is planned at Jeffery hydro during the fall, which will result in a suspension of minimum diversions due to the shutdown of both units required at the plant. He also reported they are contemplating dewatering J-2 tailrace to do repairs in October which would require a suspension of operational flows for 17-30 days. Webster reported that NPPD has no major maintenance activities planned at this time. Whitmore reported that the EA will accrue around 48 kaf by the end of the non-irrigation season for a total EA volume of around 70 kaf by May 1. She conveyed that, although the Service would still like to explore using the EA to facilitate pulse flows, a decision was made to not try a pulse test this year. This decision was based, in part, on projected releases which would result in no EA carry-over at the end of the irrigation season if 10 kaf were used on a pulse flow test and 60 kaf were used to supplement summer flows. She is still interested in working with the EAC/RCC to pre-plan for a future pulse test, however. Hardcopies of a revised pulse flow test proposal, emailed earlier in the week, was provided. She explained that the new proposal was modified based on comments received last year. Kwapnioski voiced his opinion that the ramp rates in the proposal were not acceptable, that using 1984 hydrology to model attenuation is not realistic because it was an extremely wet year, and that it would probably take more like 30 kaf instead of 10 kaf to do the proposed test (e.g., when NPPD was required to make similar releases in 1990, they had to release 80 kaf to maintain 2,000 cfs at G.I. and saw significant attenuations. The adequacy of the 36-hour release duration to achieve the desired pulse was also questioned. The bottleneck at North Platte was discussed briefly. It was mentioned that 20-25 kaf would be needed just to ramp up to 3,000 cfs at North Platte. When asked how the proposal could be improved, Kwapnioski recommended we use a more realistic hydrograph for modeling purposes (e.g., use hydrologic conditions that occurred in the past during actual pulse flow events comparable to what we are trying to achieve) and that we look at historic operations to see what ramp rates would be acceptable. 3