Section 455-1-004 - Minimum Standards Governing Location of Obstructions and Substantial Improvements in the Floodplains for the Base Flood The following minimum standards shall apply when an obstruction is to be located or substantially improved within the floodplain of a base flood. In the event of a conflict between the following minimum standards and those in Section 005, the minimum standards in Section 005 shall govern.
004.01 No new construction, substantial improvements, or other obstruction (including fill) shall be permitted unless it is demonstrated that the cumulative effect of the proposed new construction, when combined with all other existing and anticipated new construction or substantial improvement, will not increase the water surface elevation of the base flood more than one foot at any location.004.02 To the extent otherwise permitted by the minimum standards in this Chapter, all new obstructions and substantial improvements shall (i) be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the obstruction, (ii) be constructed with materials and utility equipment resistant to flood damage, (iii) be constructed by methods and practices that minimize flood and flood related damages, and (iv) be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.004.03 All public utilities and facilities, such as sewer, gas, electrical, and water systems shall be located and constructed to minimize or eliminate flood damage to such utilities and facilities.004.04 New and replacement water systems shall be designed to minimize or eliminate infiltration of flood waters into the system.004.05 New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharges from the system into flood waters.004.06 On-site waste disposal systems shall be designed to avoid impairment to them or contamination from them during flooding.004.07 All new construction and substantial improvements of residential structures shall have the lowest floor (including basement) elevated to or above one foot above the base flood level.004.08 All new construction and substantial improvements of non-residential structures shall (i) have the lowest floor (including basement) elevated to or above one foot above the base flood level or, (ii) together with attendant utility and sanitary facilities be designed so that below the level one foot above the base flood level the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. Floodproofing measures shall be consistent with the flooding characteristics of the drainway or watercourse. A registered professional engineer or architect shall certify that the floodproofing methods to be utilized are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces, sewage backups and other factors associated with the base flood.004.09 Appurtenant structures used exclusively for storage of motor vehicles, and storage of other items readily removable in the event of a flood warning may have their lowest floor below one foot above the base flood elevation provided the structure is capable of withstanding hydrostatic and hydrodynamic forces caused by the base flood and provided that no utilities are installed in the structure except elevated or flood proofed electrical fixtures. If the structure is converted to another use, it must be brought into full compliance with the minimum standards governing such use.004.10 For all new construction and substantial improvements, fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or architect or meet or exceed the following minimum criteria: A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided. The bottom of all openings shall not be higher than one foot above grade. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.004.11 All manufactured homes to be placed or substantially improved on sites: (i) outside of a manufactured home park or subdivision (ii) in a new manufactured home park or subdivision;(ii) in a new manufactured home park or subdivision;(iii) in an expansion to an existing manufactured home park or subdivision; or(iv) in an existing manufactured home park or subdivision on which a manufactured home has incurred "substantial damage" as the result of a flood, shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above one foot above the base flood elevation, and shall be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.004.12 Manufactured homes to be placed or substantially improved on sites in an existing manufactured home park or subdivision that are not subject to the provisions of subsection 004.11 shall be elevated so that either: (i) the lowest floor of the manufactured home is at or above one foot above the base flood elevation or (ii) the manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength that are no less than 36 inches in height above grade; and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.004.13 Recreational vehicles shall either: (i) be on the site for fewer than 180 consecutive days,(ii) be fully licensed and ready for highway use, or(iii) meet the permit requirements and the elevation and anchoring requirements for "manufactured homes" of this Chapter. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick-disconnect type utilities and security devices, and has no permanently-attached additions.004.14 A watercourse or drainway shall not be altered or relocated in any way which in the event of a base flood or more frequent flood will alter the flood carrying characteristics of the watercourse or drainway to the detriment of upstream, downstream, or adjacent locations. The county, city, village or state agency responsible for any alteration or relocation of a watercourse or drainway or for approving any such alteration or relocation shall notify the Department of Natural Resources and adjacent communities prior to commencing or approving such activity.004.15 The storage or processing of materials that are in time of flooding buoyant, flammable, explosive, or could be injurious to human, animal or plant life is prohibited. Storage of other material or equipment may be allowed if not subject to major damage by floods and firmly anchored to prevent flotation or if readily removable from the area within the time available after flood warning.455 Neb. Admin. Code, ch. 1, § 004