A. Uses Allowed Without Permits: All uses allowed in the floodway, according to the provisions of subsection 12-5-2A of this chapter, shall also be allowed without a permit in the floodway fringe. In addition, individual or multiple-family subsurface sewage disposal systems are allowed only when they are reviewed and approved under laws and regulations administered by the city of Belgrade, Montana department of environmental quality or the Gallatin city-county environmental health department.
B. Uses Requiring Permits: All uses allowed in the floodway subject to the issuance of a permit, according to the provisions of subsections 12-5-2B through D of this chapter, shall also be allowed by permit within the floodway fringe. Where the requirements of section 12-5-2 of this chapter prohibit any increase in the base flood elevation in the floodway, those requirements shall be interpreted to allow up to one-half foot (1/2') increase in the base flood elevation in the floodway fringe, unless the flood insurance study describes a lower allowable encroachment at a given location. In addition, new construction, substantial improvements and alterations to structures, including, but not limited to, residential, commercial and industrial construction and suitable fill shall be allowed by permit from the floodplain administrator subject to the following conditions:
1. Compatible With Other Laws: Such structures or fill must not be prohibited by any other statute, regulation, ordinance or resolution, and must be compatible with any adopted growth policy or applicable law;
2. Enclosures: If a structure includes any fully enclosed area below the lowest floor (other than a basement, which are prohibited), use of this space shall be limited to parking, loading areas, building access, and storage of equipment or materials not appreciably affected by floodwaters. Walls shall be designed to automatically equalize hydrostatic forces by allowing for entry and exit of floodwaters. The location, number, and design of any required openings to allow for the automatic entry and exit of floodwaters shall be certified by a Montana professional engineer as meeting the minimum requirements of the national flood insurance program;
3. Floodproofing Standards: Such structures are designed and built in accordance with the floodproofing standards of chapter 6 of this title;
4. Minimal Obstruction To Flood Flows: Such structures are placed and constructed so as to offer minimal obstruction to flood flows and are anchored to prevent flotation;
5. Lowest Floor Elevation: The new construction, alterations and substantial improvements of residential structures including manufactured homes must be constructed such that the lowest floor elevation, including basements, is a minimum of two feet (2') above the base flood elevation in accordance with one of the below options. If built with a crawl space, the lowest finished interior grade of the crawl space shall be at or above the base flood elevation.
a. The structure is built on suitable fill placed at an elevation greater than or equal to the base flood elevation, and extending at least fifteen feet (15'), at that minimum elevation, beyond the structures in all directions; or
b. The structure is elevated on a backfilled permanent foundation;
6. Commercial And Industrial Structures Floodproofed: The new construction, alterations and substantial improvement of commercial and industrial structures must be either constructed as specified in subsection B5 of this section, or be adequately floodproofed to an elevation no lower than two feet (2') above the base flood elevation. Floodproofing shall be accomplished in accordance with chapter 6 of this title and shall further include impermeable membranes or materials for floor and walls, watertight enclosures for all windows, doors, and other openings, and be certified by a licensed Montana professional engineer or architect that the floodproofing methods are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces associated with the base flood:
a. Structures whose lowest floors are used for a purpose other than parking, loading, or storage of materials resistant to flooding shall be floodproofed to an elevation no lower than two feet (2') above the base flood elevation. Floodproofing shall include impermeable membranes or materials for floors and walls and watertight enclosures for all windows, doors, and other openings. The floors and walls shall be designed and constructed of materials resistant to flooding to an elevation no lower than two feet (2') above the base flood elevation. These structures shall also be designed to withstand the hydrostatic, hydrodynamic, and buoyancy effects of the base flood.
b. Floodproofing of electrical, heating, and plumbing systems shall be accomplished in accordance with chapter 6 of this title;
7. Anchoring Of Manufactured Homes: All manufactured homes placed in the floodway fringe must have the chassis securely anchored to a foundation system that will resist flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, over the top or frame ties to ground anchors. The following conditions also apply:
a. When a manufactured home: 1) undergoes alterations, 2) is replaced because of substantial damage as a result of a flood, or 3) is replaced on an individual site, the lowest floor must be elevated at least two feet (2') above the base flood elevation. The home can be elevated on suitable fill or raised on a permanent foundation of reinforced concrete, reinforced mortared block, reinforced piers, or other foundation elements of at least equivalent strength.
b. Replacement or substantial improvements of manufactured homes in an existing manufactured home park or subdivision must be raised on a permanent foundation. The lowest floor must be elevated at least two feet (2') above the base flood elevation. The foundation must consist of reinforced concrete, reinforced mortared block, reinforced piers, or other foundation elements of at least equivalent strength.
c. Manufactured homes proposed for use as commercial or industrial structures must be elevated and anchored, rather than floodproofed;
8. Fill: Suitable fill placed in the floodway fringe must be stable, compacted (a minimum compaction rate of 95 percent is recommended), well graded, pervious, generally unaffected by water and frost, devoid of trash or similar foreign matter, devoid of tree stumps or other organic material, and appropriate for the purpose of supporting the intended use and/or permanent structure;
9. Transportation Related Improvements: Transportation related improvements such as roads, streets, highways, and rail lines shall be designed to minimize increase in flood heights. Where failure or interruption of transportation facilities would result in danger to the public health or safety, the facility shall be located two feet (2') above the base flood elevation;
10. Agricultural Structures: Agricultural structures that have a low damage potential, such as sheds, barns, shelters, and hay or grain storage structures must be adequately anchored to prevent flotation or collapse; and all electrical facilities shall be placed above the base flood elevation; and
11. Recreational Vehicles: Recreational vehicles, if they are on the site for more than one hundred eighty (180) consecutive days are not ready for highway use, must meet the elevation requirements of subsection B5 of this section.
C. Prohibited Uses: The following artificial obstructions and nonconforming uses are prohibited within the floodway fringe:
1. Solid and hazardous waste disposal; and
2. Storage of highly toxic, flammable, or explosive materials. Storage of petroleum products may be allowed by permit if stored on compacted suitable fill at least two feet (2') above the base flood elevation and anchored to a permanent foundation to prevent downstream movement. (Ord. 2011-5, 10-17-2011)