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<br />Reduction of Flood Losses
<br />
<br />Average annual flood losses (damages to structure and
<br />contents and business losses) for the basic commercial
<br />building without flood proofing were computed to be
<br />$13,834, When the building is protected to 1 foot above
<br />the 1 OO'year flood level, the average annual flood losses
<br />are reduced to $2,080, When the level of protection is
<br />increased to 6 feet above the 1 OO'year flood level,
<br />average annual flood losses drop to $1,095, Thus,
<br />average annual flood losses can be reduced by from 85
<br />to 92 percent through flood proofing. When the present
<br />value of the 20 year reductions in flood losses is com-
<br />pared with the cost of flood proofing the following bene,
<br />fitlcost ratios are derived: 0,25 for the building wet flood
<br />proofed, 3.46 for the building raised on fill, 1,39 for the
<br />combination of fill and watertight closures, and 1,53 for
<br />the building raised on columns,
<br />
<br />The benefits that will accrue from the flood proofing of a
<br />small commercial building extend beyond flood loss
<br />reduction and flood insurance reduction, Other benefits
<br />include reduced need for flood disaster relief and an
<br />enhanced opportunity to design a unique structure at a
<br />specific site, These benefits have the potential to in-
<br />crease both the marketability and value of the commer-
<br />cial structure.
<br />
<br />Conclusions
<br />
<br />In a flood hazard area such as Jersey Shore, flood proof,
<br />ing new commercial structures in conformance with mini-
<br />mum requirements of the National Flood Insurance Pro'
<br />gram is economically justified, All three approaches to
<br />flood proofing (raising on fill, partial raising and equip-
<br />ping with watertight closures, and elevating on columns)
<br />have favorable benefitlcost ratios, From this analysis,
<br />one can conclude that a commercial building can be
<br />flood proofed in a practical manner and also be
<br />aesthetically pleasing, functional, and adaptable to the
<br />surrounding environs.
<br />
<br />Raising on fill was the most cost effective solution for
<br />flood proofing a small commercial building at the Jersey
<br />Shore site, This is explained in part, by the design of the
<br />building - a light, low,rise building - and the physical
<br />characteristics of the site - poor soil bearing capacity in
<br />an area of modest urban density, Other conforming flood
<br />proofing techniques would appear more appropriate for
<br />larger buildings or where protection against greater
<br />design events was desired, Wet flood proofing seems
<br />appropriate only in a retrofit context; otherwise damage
<br />reductions are comparatively low relative to costs,
<br />
<br />The analytical methods employed in this investigation
<br />can be used, with appropriate adjustments for local con-
<br />ditions, as guidelines for evaluating the economic feasi,
<br />bility of flood proofing commercial structures at other
<br />locations throughout the Nation, Local conditions that
<br />should be taken into consideration include topography,
<br />soil conditions, development density, construction bud-
<br />get, architectural style, and the depth, duration, and
<br />frequency of flooding,
<br />
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