§ 63.281. Evidence of Elevation or Boundary.

The Normal High Water Elevation or Boundary shall be determined by the appropriate reviewing authority (the City Engineer for water bodies, and the Planning Official for wetlands) through compilation of relevant available evidence, specific to a particular water body or wetland, which should include the following when available:

Botanical Indicators. The presence of water for sufficient periods of time precludes the existence of terrestrial plant communities and tends to establish conditions whereby shoreline plant (hydrophytic) species inhabit the nearshore and shoreline areas. Since these communities tend to change slowly, they are widely utilized to accurately distinguish the uplands from those lands susceptible to the normal inundation of a specific waterbody or wetland. The normal high water elevation or boundary is typically indicated by that point where upland, terrestrial plant communities tend to terminate and shoreline (hydrophytic) plants are established as the prevalent plant community(ies). The hydrophytic species list established by the Florida Department of Environmental Regulation (DER) shall be used to characterize the aquatic habitat, as well as shoreline areas of a waterbody or wetland. Additional plant species may be used where they are shown to be relevant to a particular situation.

Physical Indicators. Physical indicators of normal highwater elevation include any observable physical feature along a given shoreline resulting from the presence of water in a given waterbody for sufficient periods of time so as to leave a physical line, mark, or other distinguishable feature including, but not limited to water marks on trees, on older docks and sea walls, and on older bridges and abutments. In order to accurately establish the normal high water elevation, the affidavits and like testimony of long-time residents living near a particular waterbody and other acceptable collateral evidence may be used as an acceptable indicator.

Geomorphological Indicators. The normal, sustained presence of water along a given shoreline of either lakes (still waters) or streams (flowing waters) tends to leave specific, surficial indications of that normal, sustained presence, such as deposits of organic silts, peat and muck, natural beach ridges, scarps, and levees. These deposits and other indicators may be multiple, depicting historical sustained low water elevations, average elevations, and high water elevations. The normal high water elevation is typically indicated by the most landward scarp, beach ridge or level found along a particular shoreline, and is likewise indicated by the highest or most landward silt, peat or muck deposits, or the most landward stratification of those deposits.

Water Level Records. Water level elevations obtained and recorded by any governmental agency, registered land surveyor, or others whose records are verifiable by the reviewing authority may be used to determine the normal high water elevation. These records shall be accorded less weight than other individual indicators provided herein unless such records cover a period of at least 15 years.

Controlled Lake Elevations. Where lake elevations are controlled by properly engineered structures, the normal high water elevation is presumed to be one-half foot above the control elevation. Where a normal high water elevation established by this method conflicts with the other indicators contained herein, the reviewing authority shall determine the elevation or boundary. The determinations should include, when available, all of the indicators contained herein, but may include additional hydrologic surveys or engineering studies when required or permitted by the reviewing authority.

(Ord. of 9-16-1991, Doc. #25100)