Okaloosa County BOCC — February 11, 2013 — David Sherry Presentation — reading text

East Pass Inlet Management Plan David Sherry – April 16, 2013 1  Draft IMP * The study's flaws. * No bypass commitments. * Self fulfilling prophesies compound errors. * Collateral damage. * Uncertainty / Battles at every dredge. 2 Updrift / Downdrift Why should we care? 3 4  The Report The premise: Erosion from 1996 to 2007 due to transport reversal. “At beach profile R-18 immediately east of the inlet, the shoreline has retreated 282 feet between 1996 and 2007 for an annual rate of -25.6 ft/yr.” 5  The Data Date Shoreline feet from monument Nov, 1995 1408 Mar, 1996 1466 Oct, 1996 1402 Jan, 1998 1442 Jun, 2004 1583 Sep, 2005 1201 Jun, 2007 1183 Jun, 2008 1241 6 Q. So this alleged transport to the east is solely because of hurricanes -- A. It's -- Q. -- in your -- A. It seems to be, you know, strongly due to hurricanes. The big difference during the last couple of years versus the preceding years, it seems to be a strong indicator of the hurricane force.” 7 8 9 10 11 “Q. And so where is the sand that's being transport sand from that R17 area going? A. Most likely into the inlet. Q. Into the inlet itself? A. Right.” 12 “It has been determined and accepted that the littoral drift in the Panhandle area is from east to west. This being the case, Okaloosa Island beaches are giving up sand daily which is redistributed along the beaches on Eglin property.” 13 14  The Theories Seawall below MHWL – Jan 31, 2006 Transport reversal – Feb 19, 2007 Hurricanes – Feb 12, 2009 Localized Accelerated Transport The evidence and ramifications 15 Where's the bulge? Why dredge? 16 17 “Since it is just a study and we are running out of time, we could perhaps pick one and go for it, but I would like to make clear that this calibration is not one we should be very talkative about, the large deposition in the ebb shoal and the amount of scour in the channel are very different from the observed patterns and this makes me a bit nervous, 18  if there was time I would suggesting trying a lot more to make things look better. Again, since it is a study, and we will be focusing on relative changes in inlet management practices I believe the model is suited to meet the project goals, but if a skeptical type gets their hands in this calibration that can be quite harsh on us.” 19 “Q. So you changed the calibration of these little hot spot areas -- A. Yes. Q. -- from .29 millimeters to 2 millimeters without any data to support it? A. That's correct. 20 21 So why is East Pass so different? 22 If all this sounds familiar.... 23 Self fulfilling prophesies compound errors. 24 Collateral Damage 25 Conclusions 26 “The U.S. Army Corps of Engineers determined in studies in 1983 to 1992...that sand no longer enters the East Pass inlet.” 14 2,379,753 27 “The materials that are maintenance-dredged originated in the Appalachian Mountains and are transported down the river systems into Choctawhatchee Bay and from there through the East Pass inlet into the Gulf of Mexico.” 3, 5, <1 28 29 30