(A)               In addi­tion to the dam­age pre­ven­tion require­ments of Sec­tion 14–1‑6, 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 or alter­ation or addi­tion to an exist­ing build­ing val­ued at more than One Thou­sand Dol­lars ($1,000.00) or sev­en­ty (70) square feet.

(2)     Sub­stan­tial improve­ments or struc­tur­al alter­ations made to an exist­ing build­ing that increase the floor area by more than twen­ty per­cent (20%) or equal or exceed the mar­ket val­ue by fifty per­cent (50%).  Alter­ation shall be fig­ured cumu­la­tive­ly sub­se­quent to the adop­tion of this Code.  If sub­stan­tial­ly improved, the exist­ing struc­ture and the addi­tion must meet the flood pro­tec­tion stan­dards of this Section.

(3)     Repairs made to a sub­stan­tial­ly dam­aged build­ing.  These repairs shall be fig­ured cumu­la­tive­ly sub­se­quent to the adop­tion of this Code.  If sub­se­quent­ly dam­aged the entire 
struc­ture must meet the flood pro­tec­tion stan­dards of this Section.

(4)     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).

(5)     Installing a trav­el trail­er or recre­ation­al vehi­cle on a site for more than one hun­dred eighty (180) days per year.

(6)     Repet­i­tive loss to an exist­ing build­ing as defined in Sec­tion 14–1‑2.

(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 (6) inch­esbefore com­paction and should extend at least ten (10) feet beyond the foun­da­tion before slop­ing below the flood pro­tec­tion elevation.

(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)      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.

(2)     The build­ing may be ele­vat­ed on sol­id walls with the following:

(a)      The build­ing or improve­ments shall be ele­vat­ed on stilts, piles, walls, crawl­space, 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 licensed pro­fes­sion­al engi­neer or by hav­ing a 
min­i­mum of one (1) per­ma­nent open­ing on each wall no more than one (1) foot above grade with a min­i­mum of two (2) open­ings.  The open­ings shall pro­vide a total net area of not less than one (1) square inch for every one (1) square foot of enclosed area sub­ject to flood­ing below the base flood ele­va­tion; and

(d)     the foun­da­tion and sup­port­ing mem­bers shall be anchored, designed, and cer­ti­fied so as to min­i­mize expo­sure to hydro­dy­nam­ic forces such as cur­rent, waves, ice, and float­ing debris.

(i)      All struc­tur­al com­po­nents below the flood pro­tec­tion ele­va­tion shall be con­struct­ed of mate­ri­als resis­tant to flood damage.

(ii)      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.

(iii)     The area below the flood pro­tec­tion ele­va­tion shall be used sole­ly for park­ing or build­ing access and not lat­er mod­i­fied or occu­pied as hab­it­able space, or

(iv)     in lieu of the above cri­te­ria, the design meth­ods to com­ply with these require­ments may be cer­ti­fied by a licensed pro­fes­sion­al engi­neer or architect.

(3)     The build­ing may be con­struct­ed with a crawl­space locat­ed below the flood pro­tec­tion ele­va­tion pro­vid­ed that the fol­low­ing con­di­tions are met:

(4)     The build­ing must 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.

(5)     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 (1) square inch per one (1) square foot of enclosed area.  The open­ings shall be no more than one (1) foot above grade.

(6)     The inte­ri­or grade of the crawl­space below the flood pro­tec­tion ele­va­tion must not be more than two (2) feet below the low­est adja­cent exte­ri­or grade.

(7)     The inte­ri­or height of the crawl­space mea­sured from the inte­ri­or grade of the crawl to the top of the foun­da­tions wall must not exceed four (4) feet at any point.

(8)     An ade­quate drainage sys­tem must be installed to remove flood­wa­ters from the inte­ri­or area of the crawl­space with­in a rea­son­able peri­od of time after a flood event.

(9)     Por­tions of the build­ing below the flood pro­tec­tion ele­va­tion must be con­struct­ed with mate­ri­als resis­tant to flood dam­age, and

(10)    util­i­ty sys­tems with­in the crawl­space must be ele­vat­ed above the flood pro­tec­tion elevation.

(C)               Non-res­i­­den­­tial build­ings may be struc­tural­ly dry flood­proofed (in lieu of ele­va­tion) pro­vid­ed a licensed pro­fes­sion­al engi­neer or archi­tect cer­ti­fies that:

(1)     Below the flood pro­tec­tion ele­va­tion the struc­ture and atten­dant util­i­ty facil­i­ties are water­tight and capa­ble of resist­ing the effects of the base flood.

(2)     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.

(3)     Flood­proof­ing mea­sures will be incor­po­rat­ed into the build­ing design and oper­a­ble with­out human inter­ven­tion and with­out an out­side source of electricity.

(4)     Lev­ees, berms, flood­walls and sim­i­lar works are not con­sid­ered flood­proof­ing for the pur­pose of this subsection.

(D)               Man­u­fac­tured homes or trav­el trail­ers to be per­ma­nent­ly installed on site shall be:

(1)     Ele­vat­ed to or above the flood pro­tec­tion ele­va­tion in accor­dance with Sec­tion 14–1‑7(B); and

(2)     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 Ill. Adm. Code § 870.

(E)               Trav­el trail­ers and recre­ation­al vehi­cles on site for more than one hun­dred eighty (180) days per year shall meet the ele­va­tion require­ments of Sec­tion 14–1‑7(D)unless the fol­low­ing con­di­tions are met:

(1)     The vehi­cle must be either self-pro­pelled or tow­able by a light duty truck.

(2)     The hitch must remain on the vehi­cle at all times.

(3)     The vehi­cle must not be attached to exter­nal struc­tures such as decks and porches.

(4)     The vehi­cle must be designed sole­ly for recre­ation, camp­ing, trav­el, or sea­son­al use rather than as a per­ma­nent dwelling.

(5)     The vehi­cles largest hor­i­zon­tal pro­jec­tions must be no larg­er than four hun­dred (400) square feet.

(6)     The vehicle’s wheels must remain on axles and inflated.

(7)     Air con­di­tion­ing units must be attached to the frame so as to be safe for move­ment out of the floodplain.

(8)     Propane tanks as well as elec­tri­cal and sew­er­age con­nec­tions must be quick-dis­­­con­nect and above the 100-year flood elevation.

(9)     The vehi­cle must be licensed and titled as a recre­ation­al vehi­cle or park mod­el; and

(10)    must either:

(a)      entire­ly be sup­port­ed by jacks, or

(b)     have a hitch jack per­ma­nent­ly mount­ed, have the tires touch­ing the ground and be sup­port­ed by blocks in a man­ner that will allow the blocks to be eas­i­ly removed by use of the hitch jack.

(F)               Garages, sheds or oth­er minor acces­so­ry struc­tures con­struct­ed ancil­lary to an exist­ing res­i­den­tial use may be per­mit­ted pro­vid­ed the fol­low­ing con­di­tions are met:

(1)     The garage or shed shall be non-habitable.

(2)     The garage or shed shall be used only for the stor­age of vehi­cles and tools and can­not be mod­i­fied lat­er into anoth­er use.

(3)     The garage or shed shall be locat­ed out­side of the flood­way or have the appro­pri­ate state and/or fed­er­al permits.

(4)     The garage or shed shall be on a sin­gle fam­i­ly lot and be acces­so­ry to an exist­ing prin­ci­pal struc­ture on the same lot.

(5)     Below the base flood ele­va­tion, the garage or shed shall be built of mate­ri­als no sus­cep­ti­ble to flood damage.

(6)     All util­i­ties, plumb­ing, heat­ing, air con­di­tion­ing and elec­tri­cal shall be ele­vat­ed above the flood pro­tec­tion elevation.

(7)     The garage or shed shall have at least one per­ma­nent open­ing on each wall no more than one (1) foot above grade with one (1) square inch for every one (1) square foot of floor area.

(8)     The garage or shed shall be less than Ten Thou­sand Dol­lars ($10,000.00) in mar­ket val­ue or replace­ment cost whichev­er is greater or less than five hun­dred (500) square feet.

(9)     The struc­ture shall be anchored to resist flota­tion and overturning.

(10)    All flam­ma­ble or tox­ic mate­ri­als (gaso­line, paint, insec­ti­cides, fer­til­iz­ers, etc.) shall be stored above the flood pro­tec­tion elevation.

(11)    The low­est floor ele­va­tion should be doc­u­ment­ed and the own­er advised of the flood insur­ance implications.