Section 27-317. Occupancy and construction restrictions

(a) Within special
  flood hazard areas, as delineated  in  reference  standard  RS  4-4,  no
  building  in  occupancy  group  classification  J1,  J2  or  J3 shall be
  constructed or altered so as to have the lowest  floor  below  the  base
  flood elevation.
    (b)  New  construction  or substantial improvements of non-residential
  buildings within special flood hazard areas, as delineated in  reference
  standard  RS  4-4,  shall have the lowest floor elevated to or above the
  base flood elevation; or, together with attendant utilities and sanitary
  facilities, shall be floodproofed up to the  level  of  the  base  flood
  elevation,  in  accordance with the requirement of reference standard RS
  4-5.  Provided,  however,   that   new   construction   or   substantial
  improvements of non-residential buildings within area designated as Zone
  V   in  reference  standard  RS  4-4  shall  meet  the  requirements  of
  subdivision (f) of this section.
    (c) Any encroachment in  the  floodway,  as  delineated  in  reference
  standard   RS   4-4,   including  fill,  new  construction,  substantial
  improvement, or any other development that would result in any  increase
  in  flood  levels within the community during the occurrence of the base
  flood discharge, shall be prohibited.
    (d) Manufactured homes shall be anchored to resist flotation, collapse
  or lateral movement and shall be elevated on a permanent  foundation  to
  or  above  the base flood elevation or, when no base flood elevation has
  been determined, two feet above the highest adjacent grade.  Methods  of
  anchoring  may  include,  but are not limited to, use of over-the-top or
  frame ties to ground anchors. No park trailers or travel trailers  shall
  be  permitted  within  special  flood  hazard  areas,  as  delineated in
  reference standard RS 4-4.
    (e) In the case of alterations constituting a substantial  improvement
  to  parts  of  non-residential and non-institutional buildings below the
  base flood elevation, all parts below  the  base  flood  elevation  need
  comply with the applicable requirements of reference standard RS 4-5.
    (f)  All  new  construction  and substantial improvements of buildings
  within Zone V, as delineated in reference  standard  RS  4-4,  shall  be
  performed  pursuant  to  the provisions of RS 4-5. Such construction and
  improvements shall have the lowest floor elevated on adequately anchored
  pilings or columns and securely anchored to such  piles  or  columns  to
  prevent  flotation,  collapse  or  lateral  movement  resulting from the
  simultaneous action of wind and water loads on all building  components,
  and  the  lowest  portion of the structural members of the lowest floor,
  other than the pilings or columns, shall be elevated  to  or  above  the
  base  flood  elevation. For purposes of this subdivision, wind and water
  loading values shall each have a one percent chance of being equalled or
  exceeded in any given year (one hundred year mean recurrence  interval).
  In addition:
    (1) The installation of anchoring to anchored pilings or columns shall
  be subject to controlled inspection.
    (2)  The space below the lowest floor shall be free of obstruction or,
  alternatively, such space shall be constructed with break-away walls  of
  an  open  lattice  type construction which is intended to collapse under
  stress  from  abnormally  high  tides  or  wind  driven  water   without
  jeopardizing  the  structural  support of the building. Such space shall
  not be used for human habitation.
    (3) The use of fill for structural support of buildings within Zone  V
  shall not be permitted.
    (4)  The  man-made  alteration of sand dunes within Zone V which would
  increase potential flood damage to buildings shall not be permitted.

    (5) All new construction within Zone V shall be  located  landward  of
  the reach of mean high tide.
    (g)  All  new  construction  and substantial improvements of buildings
  within Zone A, as delineated in  reference  standard  RS  4-4  shall  be
  performed pursuant to the provisions of reference standard RS 4-5. Where
  such construction or improvement is not floodproofed, any fully enclosed
  space  below the lowest floor that is subject to flooding, as defined in
  section 27-317.1 of this code, shall be designed to equalize hydrostatic
  flood  forces   on   exterior   walls   automatically   (without   human
  intervention)  by allowing for the entry and exit of floodwaters. Design
  for  meeting  this  requirement  shall  be  certified  by  a  registered
  architect  or licensed professional engineer or shall meet or exceed the
  following minimum criteria:
    (1) A minimum of two openings, having a total net  area  of  not  less
  than  one square inch for every square foot of enclosed space subject to
  flooding, shall be provided.
    (2) The bottom of all openings shall be no higher than one foot  above
  grade.
    (3)  Openings  may  be equipped with screens, louvers, valves or other
  coverings or devices provided that they permit the automatic  entry  and
  exit of floodwaters.
    (h)  When  used  within  special  flood hazard areas, as delineated in
  reference standard RS 4-4, breakaway walls  shall  have  a  design  safe
  loading  resistance  of not less than ten and no more than twenty pounds
  per square foot. Use of a breakaway wall which  exceeds  a  design  safe
  loading  resistance  of twenty pounds per square foot shall be permitted
  only  if  a  registered  architect  or  licensed  professional  engineer
  certifies that the proposed design meets the following conditions:
    (1)  Breakaway  wall  collapse will result from a water load less than
  that which would occur during the base flood; and
    (2) the elevated portion of the  building  and  supporting  foundation
  system   will  not  be  subject  to  collapse,  displacement,  or  other
  structural damage due to the effects of  wind  and  water  loads  acting
  simultaneously    on    all    building   components   (structural   and
  non-structural). Maximum wind and water  loading  values  used  in  this
  determination  shall each have a one percent chance of being equalled or
  exceeded in any given year (one hundred year mean recurrence interval).