13-1-12: FLOODWAYS:
Floodways located within areas of special flood hazard established in subsection 13-1-5B of this chapter are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters which carry debris, potential projectiles and erosion potential, the following provisions shall apply:
   A.   Encroachments:
      1.   Encroachments are prohibited, including fill, new construction, substantial improvements and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge.
      2.   Under the provisions of 44 CFR chapter 1, section 65.12 of the national flood insurance regulations, a community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations; provided, that the community first applies for a conditional FIRM and floodway revision through FEMA.
   B.   New Construction; Substantial Improvements: If subsection A of this section is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of section 13-1-8 et seq., of this chapter. (1985 Code § 12-420)