§ 152.07 PROTECTING BUILDINGS.
   (A)   In addition to the damage prevention requirements of § 152.06, all buildings located in the floodplain shall be protected from flood damage below the flood protection elevation. This building protection requirement applies to the following situations:
      (1)   Construction or placement of a new building valued at more than $1,000;
      (2)   Construction or placement of a new building greater than 70 square feet in area;
      (3)   Substantial improvement as defined in § 152.02 to an existing building; or a building whose cumulative improvements, repairs or structural alterations, beginning with the first improvement, repair or structural alteration made subsequent to the effective date of this chapter, equals or exceeds 50% of the market value of the structure before the first improvement, repair or structural alteration was made;
      (4)   Substantial damage as defined in § 152.02 to an existing building; or a building whose cumulative damage repairs, beginning with the first damage repair made subsequent to the effective date of this chapter, equals or exceeds 50% of the market value of the structure before the first damage repair was made;
      (5)   Structural alterations to an existing building that increase the floor area by more than 20%;
      (6)   Installing a manufactured home on a new site or a new manufactured home on an existing site (the building protection requirements do not apply to returning a manufactured home to the same site it lawfully occupied before it was removed to avoid flood damage); and
      (7)   Installing a travel trailer or recreational vehicle on a site for more than 180 days per year; and
      (8)   Repetitive loss to an existing building as defined in § 152.02.
   (B)   Residential or non-residential buildings can meet the building protection requirements by one of the following methods:
      (1)   The building may be constructed on permanent land fill in accordance with the following:
         (a)   The lowest floor (including basement) shall be at or above the flood protection elevation;
         (b)   The fill shall be placed in layers no greater than six inches before compaction and should extend at least ten feet beyond the residential or non-residential buildings can meet the building protection requirements by one of the following methods;
         (c)   The fill shall be protected against erosion and scour during flooding by vegetative cover, riprap, or other structural measure;
         (d)   The fill shall be composed of rock or soil and not incorporate debris or refuse materials; and
         (e)   The fill shall not adversely affect the flow of surface drainage from or onto neighboring properties and when necessary, stormwater management techniques such as swales or basins shall be incorporated; or
      (2)   The building may be elevated in accordance with the following:
         (a)   The building or improvements shall be elevated on stilts, piles, walls or other foundation that is permanently open to flood waters;
         (b)   The lowest floor and all electrical, heating, ventilating, plumbing, and air conditioning equipment and utility meters shall be located at or above the flood protection elevation;
         (c)   If walls are used, all enclosed areas below the flood protection elevation shall address hydrostatic pressures by allowing the automatic entry and exit of floodwaters. Designs must either be certified by a registered professional engineer or by having a minimum of one permanent openings on each wall no more than one foot above grade. The openings shall provide a total net area of not less than one square inch for every one square foot of enclosed area subject to flooding below the base flood elevation;
         (d)   The foundation and supporting members shall be anchored and aligned in relation to flood flows and adjoining structures so as to minimize exposure to hydrodynamic forces such as current, waves, ice and floating debris;
         (e)   The finished interior grade shall not be less than the finished exterior grade;
         (f)   All structural components below the flood protection elevation shall be constructed of materials resistant to flood damage;
         (g)   Water and sewer pipes, electrical and telephone lines, submersible pumps and other service facilities may be located below the flood protection elevation provided they are waterproofed; and
         (h)   The area below the flood protection elevation shall be used solely for parking or building access and not occupied or later modified as habitable space.
   (C)   Manufactured homes, or travel trailers and recreational vehicles installed on site for more than 180 days per year, shall be:
      (1)   Elevated in accordance with division (B) of this section; and
      (2)   Shall be anchored to resist flotation, collapse or lateral movement by being tied down in accordance with the rules and regulations for the Illinois Mobile Home Tie-Down Act issued pursuant to 77 IL Adm. Code 870.
   (D)   Travel trailers and recreational vehicles on site for more than 180 days per year shall meet the requirements of division (C) of this section unless all the following conditions are met:
      (1)   The travel trailer or recreational vehicle shall be either self-propelled or towable by a light duty truck. A hitch must remain on the vehicle at all times;
      (2)   The travel trailer or recreational vehicle shall not be attached to external appurtenances such as decks or porches;
      (3)   The travel trailer or recreational vehicle shall be designed solely for recreation, camping, travel or seasonal use and shall not be used as a permanent dwelling;
      (4)   The travel trailer or recreational vehicle shall be less than 400 square feet in area;
      (5)   The travel trailer or recreational vehicle shall have wheels on all axles with tires inflated and road ready;
      (6)   If so equipped, air conditioning units shall be attached to the frame so as to be safe for movement out of the floodplain;
      (7)   If so equipped, propane tanks, electrical and sewer/septic connections shall be quick disconnect and above the flood protection elevation or otherwise made water tight;
      (8)   The travel trailer or recreational vehicle shall have a current license and title as a recreational vehicle or park model; and
      (9)   The travel trailer or recreational vehicle shall either be entirely supported by jacks rather than blocks or have a hitch jack permanently mounted, have the tires touching the ground and be supported by blocks in such a manner that will allow the blocks to be removed by use of the hitch jack.
   (E)   (1)   Non-residential buildings may be structurally dry floodproofed (in lieu of elevation) provided a registered professional engineer or architect certifies that:
         (a)   Below the flood protection elevation, the structure and attendant utility facilities are watertight and capable of resisting the effects of the base flood;
         (b)   The building design accounts for flood velocities, duration, rate of rise, hydrostatic and hydrodynamic forces, the effects of buoyancy, and the impact from debris and ice; and
         (c)   Floodproofing measures will be incorporated into the building design and operable without human intervention and without an outside source of electricity.
      (2)   Levees, berms, floodwalls and similar works shall not be considered floodproofing for the purpose of this division.
   (F)   Garages or sheds shall be protected in accordance with divisions (B) or (E) of this section unless all of the following conditions are met:
      (1)   The garage or shed shall be non-habitable;
      (2)   The garage or shed shall be used only for storage and shall not later be converted to another use;
      (3)   The garage or shed shall be located outside of the floodway;
      (4)   The garage or shed shall be located on a single-family residential lot and be accessory to an existing principal residential structure;
      (5)   Below the flood protection elevation, the garage or shed shall be constructed of flood resistant materials;
      (6)   All utilities, plumbing, heating, air conditioning and electrical shall be elevated above the flood protection elevation;
      (7)   The garage or shed shall have a minimum of at least one permanent opening on each wall no more than one foot above grade. The openings shall provide a total net area of not less than one square inch for every one square foot of floor area;
      (8)   The garage or shed shall be less than $7,500 in market value or replacement cost whichever is greater and less than 500 square feet in area;
      (9)   The garage or shed shall be anchored to resist floatation, collapse, lateral movement or overturning;
      (10)   All flammable or toxic materials including but not limited to gasoline, paint, insecticides and fertilizers shall be stored above the flood protection elevation; and
      (11)   The lowest flood elevation of the garage or shed shall be documented and the owner notified of flood insurance implications.
   (G)   A residential building may be elevated on a crawlspace provided all the following conditions are met:
      (1)   The building shall be designed and adequately anchored to resist flotation, collapse and lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;
      (2)   Any enclosed area below the flood protection elevation shall have openings that equalize hydrostatic pressures by allowing for the automatic entry and exit of floodwaters. A minimum of one opening on each wall having a total net area of not less than one square inch per one square foot of enclosed area. The openings shall be no more than one foot above grade;
      (3)   The interior grade of the crawlspace below the flood protection elevation shall not be more than two feet below the lowest adjacent exterior grade;
      (4)   The interior height of the crawlspace measured from the interior grade of the crawl to the top of the foundation wall must not exceed four feet at any point;
      (5)   An adequate drainage system must be installed to remove floodwaters from the interior area of the crawlspace within a reasonable period of time after the flood waters recede;
      (6)   Utility systems within the crawlspace must be elevated above the flood protection elevations; and
      (7)   The bottom of the lowest structural member of the first finished floor (lowest habitable floor) shall be at or above the flood protection elevation.
(Ord. 3210, passed 11-3-2003)