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MAY 11990 BaoF _79 FAr-402 <br />3) The applicant'shall be responsible for establishing and <br />maintaining fill and dune vegetation over the subject <br />seawall, and shall be responsible to mitigate any <br />off -property erosion impacts that are proven to have <br />occurred due to the seawall erosion stabilization <br />project. <br />No funding considerations are applicable <br />Public Works Director Jim Davis advised that Michael Walther <br />of Coastal Technology Corporation has prepared an analysis which <br />includes the following list of alternatives for upland <br />stabilization: <br />ALTERNATIVES <br />GENERAL: The following are descriptions of alternatives available <br />for stabilization of the uplands fronting the residence of <br />Mr. Charles Pishock. The alternatives available include: 1) <br />doing nothing, 2) dune maintenance, 3) sandbags, 4) rock <br />revetment and, 5) seawall. Table 1 summarizes these descriptions <br />and includes the limitations relative to "emergency construction" <br />of the alternative (Emergency Limitations) and limitations of <br />construction under normal conditions (Normal Limitations). <br />Doing Nothing: One alternative available to Mr. Pishock is to do <br />nothing. By selecting this alternative, Mr. Pishock would then be <br />accepting the likely failure of his residence. In particular, it <br />is expected that annual storms would undermine and cause damage to <br />the residence in the absence of the seawall. As such, this <br />alternative is not acceptable -:- <br />Dune Maintenance: ,By replacing the sand eroded from the dune <br />over long segments of shoreline, it is feasible to maintain the <br />dune and provide some improved stability to the uplands. Under <br />emergency conditions, typically it is impossible to place fill <br />faster than fill may be eroding from the dune; this condition <br />occurred at Mr. Pishock's residence during the March storm. Under <br />normal conditions, dune maintenance has been demonstrated as a <br />viable means of upland stabilization when long segments (more than <br />1 mile) are maintained. Due to end effects, dune maintenance <br />efforts over short segments of shoreline are not effective even <br />under normal conditions. In addition, dune maintenance is <br />expected, at best, to only provide for maintenance of the dune —no <br />significant added protection of the uplands is provided. <br />Sandbags: Geotextile fabrics may be sewn to form bags; these bags <br />are filled with sand and placed on the beach to attempt to prevent <br />erosion of the dune. In order for these structures to be stable <br />50 <br />