1. When will dredging start?
2. How much will the project cost and how will it be paid?
3. Can I get my dock slip dredged at the same time as the Pocket dredging?
4. What will happen to the sediment that is removed from the Pocket?
5. How long will the dredging work take?
6. Where will the channel be and what are its dimensions?
7. Will the channel be marked?
8. What kind of navigational interference can I expect while the dredging is going on?
9. Will the dredging damage my dock and bulkhead?
10. Will the dredging cause a lot of turbidity?
11. How contaminated are the excavated material?
12. Will the project damage seagrass beds?
13. How will the project impact marine life and wildlife?
14. How was Dickerson of Florida selected as the dredging contractor? What did the bid review process entail?
15. When will dredging begin?
16. Where will dredging begin? What is the dredging route?
17. What type of dredging equipment will Dickerson use to complete the project?
18. Will there be any adverse impacts, i.e. excessive noise or unpleasant odors, that will be caused by dredging operations?
19. What radio frequency can boaters use to communicate with dredging operators?
20. What should I do if I have an event planned in the Pocket during construction?
21. What will be the typical hours of dredging activity?
22. What markers am I looking for to tell me exactly where I can navigate?
23. How close can I navigate to the dredge in small channels?
1. When will the dredging start?
Dredging is expected to begin March 2010. The Timeline tab on this site explains the order of events that need to occur before dredging can begin. We will keep you updated on this as we get information.
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2. How much will the project cost and how will it be paid for?
The estimated project cost is 12 million dollars. Martin County has been successful in researching, identifying, and securing enough grant funding to offset the cost of the dredging project.
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3. Can I get my dock slip dredged at the same time as the Pocket dredging?
This option is available for property owners along the Pocket, however, they must have obtained all necessary permits before any work can begin.
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4. What will happen to the sediment that is removed from the Pocket?
Current plans are to hydraulically dredge Manatee Pocket. A discharge pipe would run from the dredge up to the staging area , which is the designated dredged material handling site. The dredged material will be sent to an off site location prior to a final placement location. Based upon the Sediment testing results, most of the dredged material is expected to be put to beneficial use rather than being sent to a landfill for disposal.
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5. How long will the dredging work take?
Dredging work may require about one year to complete if it is done on a continuous basis.
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6. Where will the channel be and what are its dimensions?
A defined channel that is 100-ft wide and has a bottom at -10-ft Mean Low Water (MLW) will run through the entire length of the main body of Manatee Pocket and will connect to the four main tributaries which are: Crooked Creek, Chapman’s Creek, Salerno Creek and Manatee Creek. Dredging will also be done in the tributaries.
The limited widths in the tributaries prevent dredging to the full dimensions of the main channel. However, dredging will generally extend the full length of the main portion of the tributaries. The Crooked Creek entrance will be dredged up to the St Lucie Blvd. Bridge. The creek bottom to the west of the bridge is private property. To view a figure of the proposed dredging project, click here.
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7. Will the channel be marked?
Yes, channel markings will be installed as part of the project. Of note is that one very small seagrass bed lies directly in the center of the channel, between the natural flows of traffic. Traffic will be diverted around this seagrass bed through channel markers as well.
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8. What kind of navigational interference can I expect while the dredging is going on?
The dredge will be operating within an enclosure to limit the migration of suspended sediments away from the dredging site. No navigation within the enclosure area will be possible. The enclosure will be as small as practical so as to limit its interference with navigation. The dredge and the enclosure will also move frequently so that the amount of time any one place is blocked will be very limited.
During active dredging, the dredge discharge pipeline will be in place and has the potential to interfere with vessel navigation locally. To the extent practical, the pipeline will be submerged and marked with buoys so that most vessels can safely pass over it. To view an animation of how the dredge equipment will work, click here.
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9. Will the dredging damage my dock and bulkhead?
The dredging program has set the cut of the dredge away from any existing structures and pilings, so that they will not be damaged. Before dredging, a comprehensive site inspection was completed to examine the dredging areas to identify structures and existing conditions so that the program could be modified as necessary to avoid damage to structures and to document the conditions of existing structures including seawalls, docks, mooring pilings boat lifts etc.
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10. Will the dredging cause a lot of turbidity?
The project will utilize a hydraulic dredge. Hydraulic dredges tend to produce less turbidity than other conventional dredging techniques. This is because they operate as an underwater vacuum cleaner. The suction captures much of the suspended sediment that may result as the dredging head moves across the bottom.
The dredging operation will use turbidity barriers when possible. Turbidity barriers are impervious screens that extends through the entire water column and physically blocks suspended sediment plumes from migrating away from the dredging operations site. The dredging operation will also include turbidity monitoring. If turbidity levels at the monitoring site reach threshold levels above the background levels, then the dredging operations will be temporarily stopped until the turbidity levels return to acceptable values.
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11. How contaminated are the excavated materials?
According to studies conducted to analyze the material, its contents are organic in nature and its origins are primarily from land erosion and human land uses. Because it is organic, Manatee Pocket can be safely dredged.
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12. Will the project damage seagrass beds?
No. A study was conducted to identify the location of the three species of seagrass that inhabit the Pocket. Through this study we will be able to avoid permanently damaging seagrass beds and minimize even temporary effects. In addition, the project is specifically tailored to create areas of seagrass habitat. The project will remove material, exposing the sandy substrates below in the hope that seagrasses will once again take root and flourish.
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13. How will the project impact marine life and wildlife?
Preserving and enhancing the environmental health of the Pocket is one of the key objectives of the dredging project. According to studies conducted to analyze the material, its contents are organic in nature and will not release unsafe chemicals into the water and wildlife. In addition, the dredging will be done hydraulically, a method specifically designed to minimize turbidity in the water and protect wildlife.
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14. How was Dickerson of Florida selected as the dredging contractor? What did the bid review process entail?
Representatives from Martin County's Coastal Engineering Division and other participating agencies - including The Army Corps of Engineers, Florida Inland Navigation District, and the South Florida Water Management District reviewed and evaluated responses received from dredging contractors.
In selecting the best contractor for the job, cost was only one of the factors that were considered. Other factors included: the Contractor's proposed work plan, project duration and timeline; Contractor's proposed Environmental Compliance Plans; Contractor's ability to reduce impact to residents and area infrastructure during the dredging process; Contractor's willingness and capacity to provide clear and continuous communication about the status of the project; and Contractor's use of technology. Based on these factors, Dickerson Florida Inc. was selected as the dredging contractor for the Manatee Pocket Project.
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15. When will dredging begin?
The construction start date is contingent upon obtaining the necessary permit modifications, which we are diligently working towards.
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16. Where will dredging begin? What is the dredging route?
Once the results from the sediment sampling are complete, the dredging route will be finalized.
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17. What type of dredging equipment will Dickerson use to complete the project?
The dredge being used for this project is a DSC 10” Hydraulic Cutter Suction Dredge. To put it simply, this dredge works like an underwater vacuum cleaner, sucking up the dredge materials.
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18. Will there be any adverse impacts, i.e. excessive noise or unpleasant odors, that will be caused by dredging operations?
The dredge is comparable to other construction equipment that operate with a diesel engine. We don’t anticipate any adverse impacts due to dredging operations.
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19. What radio frequency can boaters use to communicate with dredging operators?
Dickerson will monitor Channel 16, which is the distress channel, and will be using Channel 12 for daily construction activities for communications between the Dredge and the Work Boats.
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20. What should I do if I have an event planned in the Pocket during construction?
Anyone with knowledge of an event already set or in the planning stages in the Manatee Pocket area that will take place between December 2009 through February 2011 is encouraged to contact Nancy McCarthy with dates, times, and event details at 772-287-5272 or nancy@fireflyforyou.com
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21. What will be the typical hours of dredging activity?
The typical hours of operation are six 12-hour shifts, 7 a.m. – 7 p.m., with Sunday reserved for maintenance. However, there may be a situation where extending hours will be necessary. Any changes to the typical dredging hours will be communicated through the website.
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22. What markers am I looking for to tell me exactly where I can navigate?
During construction, standard navigational aids will be used to assist marine traffic as to areas to avoid.
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23. How close can I navigate to the dredge in small channels?
Since the main channel and the tributaries are different in size and configuration, this “distance” will vary. Constant communications will occur prior to, and while working in these areas. A float will be deployed around the dredge that will indicate a “non-travel” area.
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Contact
To post a comment about the Manatee Pocket Project, or to find out more information about the project, contact:
Kathy Fitzpatrick
Coastal Engineer of Martin County
KFitzpat@martin.fl.us
To request more information on Data and Reports on the Manatee Pocket, contact:
Richard E. Czlapinski
Coastal Engineering Consultant, Tetra Tech EC
Richard.Czlapinski@tetratech.com
For dredging or construction information, call the Manatee Pocket Hotline at 1-800-580-9149.
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