Hurricane Irene damage to Mirlo Beach

Below is our account of how and why there was massive soundside erosion in Mirlo Beach during Hurricane Irene.  This explanation has been validated by several experts.  (A report done by Coastal Science and Engineering can be viewed or downloaded at the bottom of this page.).  

What happened during Hurricane Irene.

Overall, our opinion is that NCDOT and USFWS decisions and actions, however well intended and cost effective at the time, have contributed significantly to the extreme erosion damage that occurred during Hurricane Irene.  From our common sense perspective, we believe some type of significant assistance from both agencies is appropriate and deserved.  We have communicated our opinions and expert report to both agencies without result.

THE CAUSES OF THE EXTREME EROSION AT MIRLO BEACH DURING HURRICANE IRENE.  The erosion in question occurred on the west side of NC12 from Blue Sea Rd. to Green Lantern Ct. and removed most of the sand in that area transforming property that was approximately 4 foot above sea level into a pond whose bottom is now several feet below sea level.  Nine Mirlo Beach properties as well as MBHOA roads and common areas were directly affected. All Mirlo Beach properties were indirectly affected insofar as ocean access is now limited for properties west of NC12. We also believe the power poles in standing water and remaining debris represent a significant safety hazard, and during the next nor'easter overwash,  drivers will not know there is pond just a few feet off the road.

We believe there were four important causal factors that created this extreme and focused erosion rather than the diffuse and limited erosion that normally occurs in sound side flooding.  First, the narrow breach at the boundary of Rodanthe and Pea Island Wildlife Refuge created a singular point of drainage for the 4 - 5 foot of water that flooded the area when the winds from Irene shifted to the southwest.  Second, this focal breach was most immediately caused by the canal running between the ponds in the Refuge (Paul's Ditch), which significantly increased the water pressure at the point of the breach. (Evidently this canal has been in place for many years and is jointly maintained by NCDOT and USFWS.  Several residents noted that it was cleared and re-established just prior to the storm.) Third, the sandbags placed on the east side of NC12 just north of the breach formed a dam which prevented overwash or secondary breaches, forcing all of the water through the narrow breach (plus NC12 and elevated beachfront properties south of the breach also acted as a dam). Finally, from a broader perspective, this breach (indirectly) and previous ocean side breaches (more directly) were caused by the high beach erosion rate at this "hot spot."  Given this, the breach would have been prevented had there been a program of beach nourishment of sufficient scale in prior years.  In particular, based on our previous discussions with NCDOT, we know that such a project had been planned (at least for study, R-3116D), but was set aside several years ago in deference to the Bonner Bridge plan.  Of course, there may have been good budgetary and political reasons for not engaging in beach nourishment in previous years, but it is a fact, nonetheless, that such nourishment would have prevented this damage.

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John Wesley Hutchinson,
Dec 11, 2011, 3:21 PM
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