Laserfiche WebLink
(I <br />November 15, 2018 <br />Page 3 of 7 <br />information can be used for planning of future renourishment and maintenance events. <br />Information used for the task will be based solely on data collected and analyzed by others <br />such as the current data being collected in the southern borrow area with vibracores and <br />the investigation into the feasibility of upland sand sources in the area. <br />Task 5: Storm Vulnerability <br />Stantec will provide a vulnerability assessment that will include performing a storm damage <br />vulnerability analysis by utilizing the Storm Induced Beach Change Model (SBEACH) which <br />simulates changes in the beach profile that could result from coastal storms of varying <br />intensity in terms of storm tide levels, wave heights. wave periods, and storm duration. This <br />assessment will follow a similar approach to those used in previous BPP updates. <br />Information required as input to run the SBEACH model includes the beach cross-section, <br />the median sediment grain size, and the time histories of the wave height, wave period, <br />and water elevation. This information will be gathered from existing data sources. No new <br />collection of data is proposed. If it is determined that the available data is insufficient to <br />develop an accurate model, then collection of additional data will be discussed with the <br />County. <br />Sea level rise will be discussed as it relates to the management strategies and how the <br />County can include sea level rise in their planning efforts. This discussion will be restricted <br />to the impacts of sea level rise on the proposed beach management strategies but will <br />also include a narrative on the Florida Statute requirements for local governments to <br />prepare comprehensive plans to include sea level rise considerations in their future <br />planning documents. Impacts of sea level rise to infrastructure close to the beach will not <br />be included. <br />Task 6: Storm Damage Reduction Analysis <br />The analysis of potential storm damages will be followed by an evaluation of the size of a <br />beach fill that would be required to eliminate the potential damage identified with a <br />particular storm return interval. SBEACH will be re -run to determine the size of a beach fill <br />that would be needed to eliminate that potential threat. This process will be repeated for <br />each storm and each reach for which potential damages are indicated. The outcome of <br />this analysis will be a list of beach fill dimensions needed in each reach to eliminate storm <br />damage threats to structures for storm return interval deemed to pose a potential threat. <br />It is anticipated that no more than three storm intervals will be used for this analysis. <br />The results of this analysis can be used to formulate a beach nourishment strategy that <br />would seek to equalize the magnitude of the storm damage risk for the entire County or at <br />least reduce the risk to an acceptable level. The determination of what constitutes an <br />acceptable level of risk depends on priorities established by the County. Stantec will work <br />with the County to identify and confirm these priorities. <br />;=sir •,^%i-. ._.. Y': i:`?i'?w <br />164 <br />