1. DREDGING THE PASS

2. 1999 Ten-Year Permit vs New Proposed Permit 1999 10-Yr Permit, Clam Bay Restoration and Management Plan The primary objective was environmental restoration of the ecosystem in particular the restoration of approximately 20 hectares of mangroves that died off in the northern end of the system along the strand road and upper clam bay Today’s Proposed Permit, Clam Pass Maintenance Dredging The primary objective is inlet maintenance to aid in flushing and improve environmental resources.

3. 1996 Upper Clam Bay Reminder of where we used to be…

4. Development Adjacent to Mangroves Alteration of Natural Hydrology Change in Tidal Flow Increased Freshwater Runoff Altered Hydroperiod Reduced Sheetflow - Extended Surface Water Retention - Surface Water Levels Increase - Tidal Circulation in the Mangroves becomes stagnant Prolonged Stress of submerged aerial roots Black Mangrove Die-off Below Ground Decay Subsidence Change in Avian Species Use Decline in Avian Populations Decline in Benthic Invertebrate Community Decline in Fisheries Conceptual Model of a Black Mangrove Die-off

5. REMEMBER THIS

8. (Reference) Surface Water Fluctuations During the Wet Season: Tidal Influence at a Station Situated Near the Gulf (Die-off) Surface Water Fluctuations During the Wet Season: Muted Tidal Signatures and Predominant Influence of Rain and Runoff inches

9. Clam Bay 2002

10. NEED A COMPREHENSIVE PLAN TO PROTECT THE ESTUARY WHICH CONSISTS OF ENVIRONMENTAL RESOURCES THAT ARE FOUND IN THE PASS, BAYS AND TRIBUTARIES AND THE LANDWARD HABITATS INCLUDING THE MANGROVE FORESTS, SCRUB AND DUNES Dredging Clam Pass Inlet ALONE is not answer to maintaining the health of the estuarine waterways and mangrove forest

11. When to Dredge? Dredging should occur only when the hydrologic exchange between the Gulf and the Clam Bay estuary has been reduced to the point where the biological integrity of the entire system (water and forest resources) are at risk. Clam Pass 1953 Clam Pass 1962

12. Clam Pass 1995 Clam Pass 2003 Inlet Dynamics are influenced by a variety of factors such as: Inlet Current patterns driven by tides, waves, wind, severe weather, etc. Constantly variable inlet hydrodynamics are influenced by tidal prism, channel and estuary morphology, slope, elevation, sediment type(s) and geological features, fresh water inflow, gross geometric variation, flow velocity, tidal phase and amplitude and phase, shoaling and scouring, etc…..

13. Clam Pass 2009 Clam Pass 2008 Circumstances that could necessitate dredging: 1)Pass completely closes due to a storm or other natural event 2)Inlet has lost hydraulic efficiency that is not recoverable through natural processes

14. Tide Gauges, Mangrove, Seagrass and other Ecological Indicators Monitoring Plan Purpose: To evaluate inlet characteristics and tidal dynamics within the entire Clam Bay system on a comprehensive long-term basis. CLAM PASS

17. Proposed Dredging Template

22. HYDROLOGIC EFFICIENCY OF THE ENTIRE CLAM BAY SYSTEM ECOLOGICAL CONDITIONS OF THE ENTIRE CLAM BAY SYSTEM THERE IS NO CUT AND DRIED DECISION OF WHEN TO DREDGE THE DECIESION SHOULD BE BASED UPON THE BEST SCIENTIFIC HYDROLOGIC AND ECOLOGIC DATA AVAILABLE AND BY WEIGHING THE BENEFITS OF DREDGING VS THE DETRIMENTS OF DREDGING IN RELATION TO THE ENVIRONMENT