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Alonzo Landing - Billy Goat Hole

Created by Beau Buhring on Jan 08, 2015  
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General
Dauphin Island , AL
United States
30° 15' 11.1312" N, 88° 4' 56.586" W
Alabama US
Pre-Project Conditions
Submerged Aquatic Vegetation (SAVs) present?: 
No
Pre-Construction Erosion Present?: 
Yes
Pre-Construction Erosion at Adjacent Parcels?: 
Do Not Know
Average Nearshore Slope: 
1:80.0
Existing Structures or Debris?: 
Yes
Describe Existing Structures or Debris at the Site: 
Derelict boats (removed as part of the project)
Environmental Considerations
Name of Waterbody: 
Pass Drury Channel/Fort Gaines Harbor
Site Classification: 
Straight
Maximum Exposed Fetch Distance: 
0.00 miles
Shoreline orientation relative to max. fetch distance: 
0 Degrees
Tidal Range: 
1.2 feet
Adjacent to Navigation Channel?: 
Yes
Boat wake exposure: 
Low
Project Site Within a Designated No-Wake Zone?: 
Yes
Salinity: 
Brackish: 0.5 – 30 ppt
Description of Nearby Structures: 
Fort Gaines Harbor & harbor stabilizing rock structures
Design Considerations
Was fill brought in?: 
No
Proposed nearshore slope: 
1:80.0
Length of Project: 
520 feet
Average Project Width: 
60 feet
Width of Wetlands Above MHW: 
800 feet
Structural Elements
Did the project involve a structure?: 
Yes
Type of Structure: 
breakwater
Describe construction materials: 
This breakwater is 180+/- individual, perforated, pre-cast concrete, pyramidal unit (called wave attenuation devices) arranged in two rows. The individual units have a 7.8 foot triangular base and are 5.5 feet tall.
Average distance of structure offshore (from existing MHW/NHW): 
30 feet
Structure Base Width: 
20.0 feet
Length of Structure: 
520 feet
Structure Crest Width: 
15.0 feet
Area of shallow bottom conversion to structure: 
7,200 square feet
Width of Open Water Between Structure and Wetlands: 
30 feet
Structure Side Slope (V:H): 
1:2.0
Structure Monolithic or Layered: 
Monolithic
Height of Structure Above MHW: 
1.5 feet
Maximum depth at seaward edge of structure: 
4.0 feet
Maximum depth at landward edge of structure (including fill): 
4.5 feet
Drop downs, or openings or overlaps?: 
Yes
Width of drop downs or openings: 
40.0 feet
Type of foundation: 
None
Was geotextile used in foundation?: 
No
Porosity of structure: 
High
Non-Structural Elements
Percentage of vegetative cover between structure and MHW line: 
0%
Was erosion fabric used for soil stabilization?: 
No
Primary wetland species above MHW: 
Spartina alterniflora (smooth cordgrass)
Root mat developed by vegetation?: 
No
Additional expected ecological benefits from project?: 
Significant promotion of oyster habitat (on structure)
Project Performance
Overall performance of the habitat enhancement?: 
High

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