Book 1 - City of St. Petersburg

BASIS OF DESIGN BOOK 1
3 GENERAL PLANNING CRITERIA
UNDERWATER FEATURE
CRITERIA (continued)
Appearance, Structure, Materials and Research
Because the structural and substrate appearance of a
naturally occurring reef cannot be recreated, the design of the
Underwater Feature must be developed to achieve a level of
marine beauty as an artificial habitat construction under 12
ft. of water. Aesthetically pleasing and interesting reef forms
must be created through an appropriate layout, a sectional
understanding of the project, and a dimensional study.
Several conceptual methods for artificial reef designs were
considered. These are described in Figure 3.56:
• building up by placing objects directly on the Bay
bottom
• building up by minimizing contact with the Bay bottom
• installing new piles and suspending material from these
piles
• reusing existing piles and suspending material from
them
The majority of existing piles are planned to be demolished. The
design team is willing to investigate the structural capacity of a
small (approximately 20,000 sq. ft.) area of piles to determine if
they can be kept in place and incorporated into an artificial reef.
By keeping the existing piles in place and reinforcing them with
new horizontal bracing, artificial reef balls can be suspended
far enough from the bottom to allow for shadow movement.
As with all conceptual artificial methods, careful research and
consideration will determine appropriateness for this habitat
and environment. The conceptual plans Figures 3.59 and 3.60
describe the possible reuse of existing piles as a framework
supporting the future Underwater Feature.
A variety of materials will be studied for best suitability within
existing conditions and for maximum enhancement of the
habitat (Figure 3.57). Materials include limestone boulders,
concrete pipe, reclaimed concrete piling and manufactured
artificial reef modules among others. Limestone is preferred
over concrete or other materials due to its surface, porosity,
composition and pH value. Native Florida limestone boulders
of varying sizes are available from Crystal River, Brooksville and
other active quarries in the area. A mix of different materials such
as limestone boulders, reclaimed pilings and concrete support
slabs can be used in combination.
With any of these conceptual methods, a natural “reference”
habitat must be identified to determine the ecological goals for
the Underwater Feature. Scientific studies comparing natural and
manmade material for artificial reefs are available, as are studies
of artificial reef habitats incorporating both.
3 - 118
THE NEW ST. PETERSBURG PIER