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,8 - Steve Spann, Spann Engineering - Questions regarding 'barrier depletion' and its application, If we use the NWS PMP w/out barrier adjustment, what are the results? What ensued was a discussion regarding orographic adjustments to the PMP (whether to add or subtract?) Not about numbers to be adjusted but the concept of adjustments techniques was discussed, Larry Lang, CWCB - Stated that he respected the technical credentials of alI that were involved however, that we must conclude the meeting, Steve Spann, Spann Energy - Made statements that policy will dictate the benefit/cost of any decisions ultimately made, He further expressed our ability and need to take advantage of new science and technology in these problems? Finally, he pointed out that we need to get an idea of the real risks involved in the project. We need to truly define the problem then encircle the problem, Spann pointed out that discussion needs to shift to policy making discussion, The current federal policies embrace a zero risk and zero loss policy that needs to be more of a risk analysis and measured against cost effectiveness and reasonable risks, The BOR is moving towards risk analysis and we need to take advantage of the new science and technology, BilI Miller USACE - What is also important in this item is what will be the temporal distribution of the prccipitation, because that will have impacts on what the final PMF is, Larry Lang - We will get a 'Final' draft to all reviewers, May 16th 2003 is the final due date for technical review comments by the National Weather Service, Advisory Committee and the TRP, We will include all comments in the final report and they will be addressed to the extent possible in the Final Report, The Advisory Committee will need to work with the congressional delegation to get language added to the House Report that will enable the Corps the latitude to review the 2003 A W A "Site Specific Probable Maximum Precipitation Study for the Cherry Creek basin" and start the ensuing Probable Maximum Precipitation Study, Larry Lang thanked alI for attending and concluded the meeting, Meeting Conclusions and Statements: Three primary factors were found in the A W A team site-specific study results . Moisture depletion by the Palmer and Kiowa barriers . Spatial distributions of extreme rainfalI . Orographic effects within the basin Comparison - A W A team & NWS PMP Study findings: 24 hours 72 hours NWS PMP values 21,1 inches 24,7 inches A W A team PMP values 14,0 inches 15.4 inches Change 34% lower 38% lower Applying the A W A team findings to the 1995 NWS study results for basin average PMP, If you subtract out factors that A W A believes are more appropriate for the Cherry Creek basin you would end up with the numbers in red, -NWS PMP -Barrier depletion -10% -No orographic increase - 9% -Area size adjustment - 2.1 % -NWS basin average rainfalI -A W A team PMP average rainfalI 24 hours 21.10" 18,99 " 17.28 " \3,65 " \3,65 " 14.00 " 72 hours 24,70 " 22.23 " 20.22 " 15,98 " 15,98 " .15.40 " Flood Protection. Water Project Planning and Finance. Stream and Lake Protection Watee Supply Protection. Conservation Planning