Agenda 04/24/2014 PELICAN BAY SERVICES DIVISION
Municipal Service Taxing and Benefit Unit
NOTICE OF PUBLIC MEETING THURSDAY, APRIL 24, 2014
THE CLAM BAY COMMITTEE OF THE PELICAN BAY SERVICES
DIVISION WILL MEET THURSDAY, APRIL 24 AT 1:00 PM AT THE
COMMUNITY CENTER AT PELICAN BAY, 8960 HAMMOCK OAK DR.,
NAPLES, Fl.
AGENDA
The agenda includes, but is not limited:
1 . Roll call
2. Agenda Approval
3. Audience comments
4. Discussion of draft text on parameters to be used to determine if
dredging is needed
5. Discussion of draft text on typical dredge cuts and maximum dredge
cuts
6. Discussion of goal and objectives of management plan
7. Discussion of suggested edits for the management plan
8. Possible new reports/activities for FY 2015
9. Timeline and funding for 10-year permit application
10. Update on boats in Clam Bay and revised ordinance
11 . Update on Moorings Bay Citizens Advisory Committee
12. Workshop on May 14
13. Next meeting
14. Other
15. Adjourn
ANY PERSON WISHING TO SPEAK ON AN AGENDA ITEM WILL RECEIVE UP TO ONE
(1) MINUTE PER ITEM TO ADDRESS THE BOARD. THE BOARD WILL SOLICIT PUBLIC
COMMENTS ON SUBJECTS NOT ON THIS AGENDA AND ANY PERSON WISHING TO
SPEAK WILL RECEIVE UP TO THREE (3) MINUTES. THE BOARD ENCOURAGES
YOU TO SUBMIT YOUR COMMENTS IN WRITING IN ADVANCE OF THE MEETING.
ANY PERSON WHO DECIDES TO APPEAL A DECISION OF THIS BOARD WILL NEED
A RECORD OF THE PROCEEDING PERTAINING THERETO, AND THEREFORE MAY
NEED TO ENSURE THAT A VERBATIM RECORD IS MADE, WHICH INCLUDES THE
TESTIMONY AND EVIDENCE UPON WHICH THE APPEAL IS TO BE BASED. IF YOU
ARE A PERSON WITH A DISABILITY WHO NEEDS AN ACCOMMODATION IN ORDER
TO PARTICIPATE IN THIS MEETING YOU ARE ENTITLED TO THE PROVISION OF
CERTAIN ASSISTANCE. PLEASE CONTACT THE PELICAN BAY SERVICES DIVISION
AT (239) 597-1749. VISIT US AT HTTP://PELICANBAYSERVICESDIVISION.NET.
4/21/2014 8:48:37 AM
Clam Pass Maintenance Dredging Design Criteria
Draft Report
April 2014
Prepared by
Humiston&Moore Engineers
Contents
Background 1
Governing factors for Inlet Channel Stability 2
Bay Tide Range 4
Physical monitoring data analysis 4
Section A Inlet Channel 4
Section B Flood Shoal 9
Section C Outer Flood Shoal 17
Inlet Channel Length 23
Ebb shoal 23
Summary and Recommendations. 28
Background
This report provides an overview of the governing factors to establish design criteria for future
maintenance dredging for Clam Pass. These factors are based on the physical nature of Clam Pass and
monitoring data of the inlet evolution.
Clam Pass is a small wave dominated inlet on the southwest coast of Florida that provides a tidal
connection to 500 acres of wetland preserve. The relatively small tidal prism of Clam Bay provides a
critical balance between tidal flow in and out of the inlet channel and littoral processes moving to the
inlet.This affects the inlet hydraulic efficiency over time,especially when littoral transport rates are high
due to periods of high wave energy. During the 1990's, Clam Pass was subject to channel migration as
well as closure, and frequent dredging was necessary to keep the inlet open. In 1999 Collier County, in
cooperation with the community of Pelican Bay, which borders Clam Bay, implemented The Clam Bay
Restoration and Management Plan. The purpose of the plan was to provide more sustainable tidal
flushing of the wetland preserve by keeping Clam Pass open longer.The plan included dredging the inlet
channel and parts of the flood shoals which had accumulated sand over many years. Those interior
shoals, when present, reduce the tidal prism by obstructing tidal flow to bay areas beyond the
immediate vicinity of the inlet.The implementation of The Clam Bay Restoration and Management Plan
resulted in significant increase of the tidal prism relative to conditions prior to the 1999 dredging. The
plan also included monitoring and maintenance dredging which occurred at approximately 4 year
intervals.As a result,the inlet remained open for 12 years,and the areas of stressed or dying mangroves
recovered.
Clam Pass requires maintenance dredging to remain an open and viable inlet and bay system. Following
the 1999 dredging, maintenance dredging occurred in 2002, 2007 and 2013. The most recent
maintenance dredging in 2013 took place following inlet closure in late 2012. Following the passage of
Tropical Storms Debbie and Isaac and high energy wind and wave conditions during 2012, the inlet
shoaled rapidly, resulting in inlet closure in September of 2012. The County obtained a state permit for
the continued maintenance dredging of the inlet. Subsequently, the County, through the Pelican Bay
Services Division (PBSD), obtained a federal permit to reopen the inlet, following the same channel
template that had been permitted since 1999.The complete closure of the inlet in late 2012 resulted in
the collapse of its ebb shoal onto the beach and a relatively large volume of sand was pushed onshore
by waves.The inlet reopening was completed in April 2013 and tidal exchange between the bay and the
Gulf of Mexico was restored to near design levels.
1
Governing factors for Inlet Channel Stability
The inlet channel is one part of a larger tidal inlet system where the inlet connects the bay system to the
Gulf of Mexico. The tidal flow through flood and ebb tides interacts with active beach wave and
sediment transport processes that influence the stability of a tidal inlet. The morphologic features of a
tidal inlet include ebb shoal,flood shoal and inlet channel. Figure 1 illustrates these three features. The
flood shoal includes the sand shoals on the bay side of the inlet channel.The flood shoal is less dynamic
than the gulf side of the inlet as it is influenced mainly by tidal flow and sheltered from the varying wave
conditions on the open coast side.The ebb shoal features can be explained as sand bar features forming
a delta on the open coast side of the inlet.The ebb shoal delta shields the inlet channel from waves and
provides pathways for sand transport along the coast to bypass the channel without shoaling the inlet
closed. A stable inlet system requires an ebb shoal feature that prevents rapid shoaling at the inlet
mouth. The inlet channel maintains its flow cross section through tidal flow that scours the channel to
required flow area while the waves are moving large amounts of sand along coast. The stability and
dynamics of a tidal inlet is based on the balance of the two forces of tidal flow versus wave induced
current and sand transport. The direction of wave action plays a significant role in the shape and
dynamics of the inlet features.
Clam Pass is critically stable but subject to shoaling and therefore requires periodic maintenance
dredging to prevent inlet closure. The relatively small bay area compared to other estuaries in
southwest Florida provides adequate tidal flow to keep the pass open under typical conditions. The
narrow nature of the flood shoal area,surrounded by mangrove forest limits the flood shoal capacity to
maintain an equilibrium volume and bypass additional sand to the gulf and bay waters. The
accumulation of sand over long periods of time, especially within the flood shoal and inlet channel
creates additional resistance to flow. This additional resistance causes a reduction in the tidal range
within the bay and consequently reduces the flow through the pass. Reduced flow through the pass may
be detrimental to the pass remaining open. Maintenance dredging to restore the flow rates to stable
magnitude is needed prior to reaching such shoaling conditions. The design criteria presented in this
report aim to establish guidelines for the inlet stability to assist in determining the need for
maintenance dredging. Design objectives also aim to minimize dredging to essential maintenance
needed to maintain an open inlet and protect the valuable environmental resources by restoring
flushing and to allow natural evolution of the inlet morphological features.
The hydraulic and physical monitoring data of the Clam Bay system collected since 1998 to date were
used to evaluate the governing parameters for the inlet hydraulic stability.The monitoring data for clam
pass indicate that the dynamic nature of the pass is consistent with that of a wave-dominant small tidal
inlet where the inlet channel and ebb shoal morphologic features (sand bodies) may change shape
following sustained wave and wind conditions. During the summer months, persistent winds and waves
from the southwest cause the inlet channel and ebb shoal to migrate to the north. The fall and winter
wave climate is predominately from the northwest direction, which pushes the pass southward. The
seasonal variation of wind/wave energy windows and the temporal cycle of the tides result in the
shifting of the channel entrance and morphologic features around the inlet entrance. Recently collected
monitoring data shows the pass to be hydraulically stable, with an adequate flow cross section to
maintain the pass open.The data also show the dynamics of the inlet channel and ebb shoal features.
2
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Bay Tide Range
The existing hydraulic monitoring program provides water level measurements at several stations within
the bay system.The hydraulic monitoring data provides a record of the tidal range in the bay which is an
indicator to the tidal prism or volume of water flowing through the pass at each tidal cycle. In this
analysis a review of ratios of the bay tidal range to that of the gulf tide is used as the monitoring indictor
to the flow through the pass. Figure 2 shows a definition sketch illustrating the tidal ranges for the gulf
and bay.The bay tidal range is typically smaller than that of the gulf tide due to flow resistance through
the inlet channel and shoal features. The figure also shows the locations of two of the bay tidal gages
that are used in this analysis to represent the bay tide range. Figure 3 shows a plot of the annual ratios
of bay to gulf tide from 1998 to date. The figure indicates that when the inlet was hydraulically stable
the ratio between the bay and gulf tide was between 0.6 to 0.7 over 90% of the time. The data also
show that this ratio was below 0.5 prior to 1999 dredging when the inlet was unstable and in 2012 prior
to the inlet closure.
Physical monitoring data analysis
In addition to the hydraulic monitoring program, analysis of the physical monitoring data is used to
characterize the flow areas and shoaling within the channel and flood shoal areas. The physical
monitoring data includes bathymetric surveys of the inlet channel, flood shoal and ebb shoal features.
The data analysis includes evaluation of the flow cross-section areas in three main sections of the
dredging template, Sections A, B and C. Figure 4 shows the dredge template and the three monitoring
segments. Section A represents the inlet channel, Section B represents the seaward part of the flood
shoal and Section C represents the bay side part of the flood shoal. The analysis included evaluation of
the cross section of flow below mean high water and volume of sand within each segment. The cross
section of flow was computed at each survey station spaced approximately 50 feet apart. The average
and minimum cross section areas were used as indicators of the physical condition of the flow area
through each of the three segments.The cross section areas were compared to the design cross section
area of 2013 dredging and the inlet conditions in 2004 and 2008. The 2008 and 2004 inlet conditions
were used as a background benchmark for inlet conditions near equilibrium as the 2004 and 2008
survey were completed 2 years and 16 months following the 2002 and 2007 dredging event respectively.
These conditions represent the inlet at stable conditions after the post dredging adjustment phase.
Section A Inlet Channel
The indicators used in this analysis were average cross section area, minimum cross section area and
total volume of sand within Section A.
Figure 5 shows the change of average flow cross-section area below mean high water for Section A.The
figure covers the time period from January 2013 (pre-dredging conditions) to April 2014 (12 months
post-dredging). The figure shows the change in cross-section area from pre-dredging conditions when
the inlet was closed and its evolution immediately following dredging to 4 months, 7 months, and 12
months post dredging. The figure also shows the benchmark reference areas for the 2004 and 2008
average cross sections and the 2013 design cross section area. The data indicate that following the inlet
opening in 2013 the average cross section shoaled below the design area while the inlet morphologic
features were forming.After the initial adjustments the cross section area increased to above the design
area and 2008 conditions, but remained below the 2004 conditions.
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Figure 6 shows the change of the minimum flow cross section area below mean high water for
Section A. The figure also shows the change in minimum cross section area from pre-dredging to
12 months post dredging with comparison to the 2004 and 2008 minimum cross sections and the 2013
design cross section area.The data indicate that following the inlet opening the minimum cross section
shoaled then steadily increased. The minimum cross section area remained smaller than the design
cross section area, but approaches the design cross section area after 12 months.
Figure 7 shows the change in total volume of sand accumulated in the dredge template since inlet
opening. The figure shows that the Section A dredge template has accumulated sand within the dredge
cut. It should be noted that the channel migrates and meanders within in the vicinity of the dredge cut.
Thus,this indicator should not be used as a measure of critical conditions of the channel.
Figure 8 shows a table of the design criteria parameters for Section A with comparisons to post dredging
measurements. Recommended target values for each parameter are shown in red.
Section B Flood Shoal
The cross section area of flow through the flood shoal in Section B is an important indicator of the flow
exchange between the bay and inlet and the flow efficiency to maintain the tidal range within the bay.
Figure 9 shows the change of average flow cross section area below mean high water for Section B since
inlet reopening.The figure covers the time period from January 2013 (pre-dredging conditions when the
inlet was closed) to 12 months post dredging in April 2014. The figure shows how the average cross
section evolved immediately following dredging to 4 months, 7 months and 12 months post dredging.
The figure also shows the benchmark reference cross section areas for the 2004 and 2008 conditions
and the average design template dredged in 2013.The data indicate that following the inlet opening the
average cross section shoaled below the design area while the inlet morphologic features were forming.
This process has continued throughout the 12 months post dredging. The cross section area remained
larger than 2004 and 2008 conditions during the first 6 months post dredging then shoaled significantly
in the following 6 months. The 12 months post dredging data indicate that the average cross section
area within Section B became smaller than both historical benchmark conditions of 2004 and 2008.
Figure 10 shows the change of the minimum flow cross section area below mean high water for
Section B since inlet opening. The data indicate that following inlet opening the minimum cross section
shoaled to a level similar to the 2008 conditions.After the initial post dredging adjustment the minimum
cross section area of flow, the 4 month and 7 month post dredging conditions became larger than the
conditions of 2004 and 2008. However, at 12 months post dredging the minimum cross section dropped
below the 2004 and 2008 conditions.
Figure 11 shows the change in total volume of sand accumulated in the dredge template following inlet
opening.The figure shows that over 5,500 cubic yards of sand were dredged from Section B.Over the 12
months since dredging nearly 5,000 cubic yards have accumulated in Section B. The amount of material
accumulated in Section B after 12 months was much greater than the 2004 and 2008 conditions.
Figure 12 shows a table of the design criteria parameters for Section B with comparisons to post
dredging measurements. Recommended target values for each parameter are shown in red.
9
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Section C Outer Flood Shoal
Section C represents the outer (bay side) flood shoal area of Clam Bay which is also a junction in the
Clam Bay system where flow from the north and south tributaries connects to the pass. Restriction of
this area below design levels may reduce the tidal ranges in the bay system and therefore reduce tidal
flow through the pass. Only part of Section C was dredged in the 2013 maintenance dredging. This
analysis is presented in part based upon the dredged portion of Section C and in part based upon the
entirety of Section C.
Figure 13 shows the change of average flow cross section area below mean high water for the dredged
portion of Section C in 2013. The figure covers the time period from January 2013 to 12 months post
dredging. This illustrates pre-dredging conditions when the inlet was closed, how the average cross
section evolved immediately following dredging,4 months,7 months, and 12 months post dredging.The
figure also shows the 2008 average cross section area and the design template area dredged in 2013.
The data indicate that since Section C was partially dredged the average cross section remained below
the 2008 conditions. The data also shows that the average cross section area in the dredged portion of
Section C was similar to the 2008 conditions at 7 months post dredging and approached pre-dredging
conditions at 12 months post dredging.
Figure 14 shows the change of the minimum flow cross section area below mean high water for all of
Section C following inlet opening. The data indicate that since Section C was partially dredged the
average cross section generally remained below the 2004 and 2008 conditions.
Figure 15 shows the change in total volume of sand accumulated in the dredged portion of Section C
since inlet opening. The figure shows that over 2,000 cubic yards of sand were dredged from Section C.
Over the 12 month period since dredging, approximately 1,500 cubic yards have accumulated in
Section C. The accumulated material in the dredged portion of Section C is greater than the conditions
of 2004 and 2008.
Figure 16 shows the change in total volume of sand in all of Section C including the part that was not
dredged in 2013. This figure illustrates the relative amount of dredging to the total volume within the
template.The figure also shows the volumes within the template for 2004 and 2008 conditions.
Figure 17 shows a table of the design criteria parameters for Section C with comparisons to post
dredging measurements. Recommended target values for each parameter are shown in red.
17
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Inlet Channel Length
The channel length is an important factor in the inlet stability parameters. A longer inlet channel will
provide greater resistance to flow. Higher flow resistance will reduce the tidal range and increase the
phase lag with the gulf tide which reduces the tidal prism and flow through the pass.
Figure 18 shows a selection of aerials showing Clam Pass from 2004 to 2013.The figure shows the range
of channel orientation and change in channel length and beach width on both sides of the inlet during
that period.
Figure 19 shows a plot of the approximate channel length measured at the center line of the channel
through Section A from open coast to the beginning of Section B. The plot shows the dredged channel
length of approximately 250 feet. Pre-dredging conditions show a channel length of over 500 ft. The
data shows the channel in Section A meandered to over 600 feet in length before the inlet closed in
2012.
Figure 20 shows a table of the design criteria parameters for channel length with comparisons to post
dredging measurements and mapping of the channel evolution since reopening in April 2013. The
recommended target value for channel length is shown in red.
A similar situation also occurs in Sections B and C. After dredging, these Sections behave as bay areas
where sand may accumulate. As sand accumulates these areas become channelized.This channelization
increases the overall channel length and adds to the flow resistance and attenuation of the bay range.
When the flood shoal areas fill to capacity,the connection between the gulf and bay become a very long
meandering channel that dissipates the tidal range and diminish the flow rate beyond critical conditions
needed to keep the pass open. Such conditions existed in the late nineties and in 2012 prior to inlet
closure. Maintenance dredging of Sections B and C as conducted in 1999, 2002, 2007 and partially in
2013 is necessary to keep the inlet stable.
Ebb shoal
The size and shape of the ebb shoal is a key factor to the stability of the inlet that supports the stability
of the pass. The ebb shoal helps to keep the inlet open when facing storms and big wave events. The
ebb shoal delta provides sheltering to the channel and sand bypass pathway around the inlet without
filling the pass closed.The shape and volume of the ebb shoal are additional indicators of the stability of
the inlet. Ebb shoal critical conditions include onshore collapse of the ebb shoal that can be indicated by
significant change in ebb shoal offshore distance, volume, and increase in dry beach areas adjacent to
the inlet.
Figure 21 shows a table for the ebb shoal design criteria parameters and monitoring measurements
since inlet opening in April 2013. Recommended target values for the ebb shoal are presented in red.
23
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Summary and Recommendations:
This draft provides the main interrelated inlet stability indicators to be monitored for the management
of Clam Pass. The inlet design criteria include "target" ranges to be observed for the following
parameters; Bay Tidal Range, Average and Minimum Cross Section Flow Area, Volume of Shoaled
Material within the template, Channel Length and Ebb Shoal Size and Area. The following monitoring
measures are recommended to be included in the inlet management plan.
1. It is recommended to continue to monitor the tide range in the bay on monthly basis to
understand the level of hydraulic stability of the system. Based on previous tidal data
monitoring records, inlet flow stability can be indicated when the tidal range ratio remains
above 0.6. If the monthly tidal range ratio drops below 0.6 but above 0.5, further monitoring is
needed to observe monthly trends. If the range drops below 0.5 or displays a downward trend
for three consecutive months, then physical monitoring surveys should be done promptly to
evaluate potential shoaling areas that could be impeding the tidal flow.
2. The physical monitoring data is important to quantify the flow areas and shoaling throughout
the dynamic parts of the system. It is necessary to continue to monitor the physical changes in
the pass annually under stable hydraulic monitoring indicators. However, It is recommended to
monitor the physical changes at 6 month interval when possible. If tidal monitoring data show
relative tidal ranges in the critical range,field observation while continuing to monitor the tidal
range for the following months are necessary. If the hydraulic monitoring indicates a continued
trend down towards the unstable range, then additional physical monitoring should be done as
an emergency survey to quantify shoaling areas and examine need for maintenance dredging.
3. The design criteria identified in this report should be used as indicators to the level of stability
for the pass. When dredging is deemed necessary, it is recommended to follow the design cross
section areas as stated in the design range with consideration to existing conditions at the time.
Some modifications to the dredging template are recommended for future permitting. These are
intended to create a template that more closely mimics stable inlet conditions and to provide simplified
design cut dimensions based on the NAVD survey datum.
Typical cross sections for the adjusted template are provided in Figures 22, 23, and 24. Typical cross
sections are shown for bay areas in Sections B and C where the bay is wider than the target cross section
area. In areas where the bay is limited by mangroves, the width of the cut will be limited in order to
maintain a five foot buffer to the mangroves.
28
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
TABLE OF CONTENTS
1.0 Introduction
Purpose of the Clam Bay NRPA Management Plan
Development of the Clam Bay NRPA Management Plan
Role of Pelican Bay Services Division
2.0 Overview of the Clam Bay NRPA
Description of the System
Adjacent Communities
Natural History
Historical Overview
Mangrove Die-off and Restoration
Time line of important events within the Clam Bay system
Time line specific to establishment of the Clam Bay NRPA
3.0 Resource Descriptions
Soils
Topography
Climate
Natural Communities
Invasive Exotic,Non-native,and Problem Species
Listed Species
Other Species
Plant Species
Animal Species
Hydrology
Water Quality
Archaeological Resources
Inlet Dynamics
Recreational Use
4.0 Authorized Construction Activities
List of permits and work undertaken to date
5.0 Management Goal and Objectives
Management action/work required,performance criteria and monitoring, responsible
entities,timeframe
1. Maintain and protect the native floral and faunal communities within the Clam Bay
NRPA
2. Protect archaeological sites within the Clam Bay NRPA
3. Ensure recreational activities are environmentally compatible within the Clam Bay
NRPA
4. Ensure the estuary has adequate tidal and freshwater flows to maintain ecological
health within the Clam Bay NRPA
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
5. Monitor, maintain, and where possible and economically feasible, enhance water
quality within the Clam Bay NRPA
1
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
1.0 Introduction
Purpose of the Clam Bay NRPA Management Plan
The purpose of this management plan is to provide guidance and direction for the management
of the Clam Bay Natural Resource Protection Area (NRPA). This plan will form the basis by
which future management decisions can be made by identifying the appropriate management
techniques necessary to protect, preserve, maintain and monitor the natural resources and their
uses within the Clam Bay NRPA.
This plan, in addition to providing a brief historical perspective of activities undertaken within
this system, will identify management goals and objectives; develop methods to achieve these
goals and objectives; and develop implementation, assessment, and evaluation strategies that
strive to balance resource protection with recreational use. While the 1998 Clam Bay
Restoration and Management Plan (CBRMP) focused on mangrove health and recovery, this
plan will address all floral and faunal components of the NRPA, not just the mangroves. The
current Management Plan will draw from the 1998 CBRMP, input from multiple interested
stakeholders, and the findings of 15 years of biological and hydrographic monitoring activities
within the system to outline the goal and objectives for future management and maintenance of
the ecosystems throughout Clam Bay.
The 2014 Clam Bay NRPA Management Plan (Management Plan) and any subsequent revisions
recommended by the Pelican Bay Services Division (PBSD) shall be submitted to the Collier
County Board of County Commissioners (BCC) for approval. Once approved by the BCC and
relevant regulatory agencies, this Management Plan, or future amended plans, will supersede all
others and will serve as the primary guidance tool for future permitting and other management
activities necessary to protect,preserve,maintain, and monitor resources within the system.
Development of the Clam Bay NRPA Management Plan
Turrell, Hall&Associates, Inc. served as the principal consultant for the Management Plan.
This consultant firm has a long history of work in the Clam Bay NRPA and was responsible for
the implementation of the 1998 CBRMP that resulted in the successful restoration of Clam Bay's
mangrove forest. The coastal engineering firm of Humiston&Moore, Inc.provided input and
monitoring data for the 2014 Management Plan relative to Clam Pass and the dredging activities
and templates.
The PB SD Clam Bay Committee consists of members of the Pelican Bay Services Division
Board,which is an advisory board to Collier County's Board of Commissioners. The Clam Bay
Committee met regularly in 2013 and 2014 and provided input and direction to the consultants.
Additional regular input was provided by representatives of the Conservancy of Southwest
Florida;the Mangrove Action Group; and the local Calusa Group of the Sierra Club. All
Committee and Board meetings were properly noticed,open to the public, and allowed audience
participation.
2
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
Input was also solicited via notices to more than 30 area businesses, government officials and
employees, condominium associations, and individuals who regularly use Clam Bay. These
representatives were invited to participate in two meetings held in the spring of 2013. Many
have attended and provided comments at the periodic meetings of the PBSD Clam Bay
Committee where drafts of the Management Plan have been discussed. Stakeholders were also
notified in April 2014 that a draft of the Management Plan was available on the PB SD's website
and they were invited to send their comments to the PBSD's office and/or attend a workshop
about the Clam Bay NRPA Management Plan on May 14,2014. A list of these area
people/organizations is included with this Management Plan.
Pelican Bay Services Division Turrell,Hall&Associates
Chairman Tim Hall—Project Manager
801 Laurel Oak Drive, Suite 302 3584 Exchange Ave
Naples, FL 34108 Naples,Fl 34104
(239) 597-1749 (239) 643-0166
Humiston&Moore Engineers
Brett Moore—Project Manager
Mohammed Dabees—Project Engineer
5679 Strand Court
Naples, FL 34110
(239) 594-2021
3
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
Role of the Pelican Bay Services Division
In order for the management and maintenance of the Clam Bay NRPA to be successful,
coordination between a myriad of local, state, and federal agencies and interested citizen's
groups is required. The Pelican Bay Services Division (PBSD)has undertaken that role for most
of the past fifteen years.
The PBSD is a dependent special district known as the Pelican Bay Municipal Services Taxing
and Benefit Unit (MSTBU). It was formed pursuant to Chapter 125 of the Florida Statutes and
was formally enabled by the Collier County Commission pursuant to Ordinance numbers 90-111
and 91-22. These ordinances were replaced in 2002 by Ordinance 2002-27 which further
clarified the basis and role of the MSTBU and PBSD Board. This MSTBU was created to,
among other things, provide for the maintenance of conservation and preserve areas within
Pelican Bay.
This responsibility was undertaken diligently from 1998 to 2009 and resulted in the
implementation of the previous 1998 Management Plan and the recovery of the mangrove die-off
areas. Per action by the BCC the responsibility for many of the monitoring and maintenance
activities associated with Clam Bay was given to the Collier County's Coastal Zone
Management Department from 2009 to 2012. In 2013, the BCC returned responsibility for the
monitoring and maintenance of the system to PBSD via Ordinances 2013-19 and 2013-61. It is
under the PBSD's direction that this current management plan has been written.
While the MSTBU is a dependent special taxing and benefit district,the PBSD is an arm of
Collier County government and makes recommendations to the BCC. The PBSD implements its
defined responsibilities within the Pelican Bay community; sets its own budget and agenda; and
regularly submits them to the BCC for approval. The BCC has regularly approved the Clam Bay
management activities and authorized the development of this Management Plan. The PB SD's
effective working relationship with the BCC is expected to continue as the PB SD serves as the
official manager of the 2014 Management Plan which is consistent with Ordinances 90-111,
2002-27, 2013-19,and 2013-61 of Collier County.
The PBSD will oversee this Management Plan and has the responsibility for its implementation
and operation over time. As such, the PBSD will plan and implement defined management
activities with BCC approval whose purpose will be to protect, preserve, maintain and monitor
the natural communities and ecological integrity of the Clam Bay NRPA.
The PBSD has several attributes which already make it a logical guiding force in the
management and maintenance of Clam Bay. The PB SD:
• Is located within the Clam Bay drainage basin;
• Has an advisory board made up of residential and business members within Pelican Bay;
• Garners fiscal support collected from local special assessments (non ad valorem taxes);
• Is accessible to the public due to its local governing board and advertised public monthly
meetings; and
4
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
• Has demonstrated a long-term commitment to the Clam Bay NRPA and a successful
track record regarding its preservation,restoration and maintenance over the past fifteen
years.
These attributes give PBSD the knowledge and expertise in matters of local concern and, in
particular, the problems, opportunities and interests of local residents as they relate to the Clam
Bay ecosystem. Its relationship to the BCC gives it an additional level of access to technical
expertise and oversight that will be necessary to assure that the Management Plan, as
contemplated in this document, is fully implemented in the field.
As part of its responsibilities, the PBSD will assemble and distribute various technical reports
and assessments as required under the Management Plan, as well as coordinate with the other
public and private groups interested in Clam Bay. The PBSD is organized for and designed to
maintain both its knowledge of the Clam Bay resources and to generate public support for the
same. PBSD will insure that the general public, residents in Pelican Bay, PBSD consultants, and
representatives from government agencies with jurisdiction over Clam Bay each have on-going
involvement and input into the Management Plan as appropriate.
5
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
2.0 Overview of the Clam Bay NRPA
Description of the System
The Clam Bay NRPA is a 570-acre estuarine system consisting of sandy beaches, shallow bays
and creeks, seagrass beds, mangrove forests, and Clam Pass on the west coast of Collier County
in southwest Florida. The Clam Bay system is part of the Cocohatchee-Gordon River Transition,
referred to by the Collier County Department of Natural Resources as Coastal Zone II. It is one
of the few remaining estuarine systems in the Cocohatchee-Gordon River Drainage System.
Aerial photographs taken prior to the construction of Vanderbilt Beach Road show that the Clam
Bay system was connected to Wiggins Pass to the north via a system of mangrove swamps and
shallow creeks with intermediate open water areas that were excavated and are now known as
Vanderbilt Lagoon (Collier County, 1994, Tropical Biolndustries, 1978). It is recognized that
the connection was marginal at best and while passable at times, it was not uniformly and
consistently navigable (Clam Bay Restoration and Management Plan, 1998).
Similarly, aerial photos of the Seagate Drive area taken prior to its construction show that Outer
Clam Bay was connected to the mangrove swamps to the south via shallow meandering creeks
and intermediate open waters leading to Doctors Pass. These creeks were only navigable by
canoes and small skiffs (Turrell,2009). These swamps to the south were eventually excavated to
become Venetian and Mooring Bays.
Today,the Clam Bay NRPA includes three primary bays: Outer Clam Bay (southernmost), Inner
Clam Bay (central), and Upper Clam Bay (northernmost), connected by a series of tidal creeks
and connected to the Gulf of Mexico by Clam Pass. The community of Pelican Bay abuts the
northern and eastern edges of the system, while the Seagate and Naples Cay communities abut
the southern portion of the system. This system is an important natural and recreational
resource for local residents and visitors. Under Florida Statute 327.46, the speed of motorized
vessels in portions of the Clam Bay NRPA can be restricted to idle speed/no wake or slow
speed/minimum wake through the enactment of Collier County ordinances and subsequent
approval by the Florida Fish and Wildlife Conservation Commission.
The Clam Bay system was designated a Natural Resource Protection Area (NRPA) by Collier
County in 1995. The purpose of the NRPA designation is to protect endangered or potentially
endangered species and to identify large connected intact and relatively unfragmented habitats,
which may be important for these listed species (Collier County Growth Management Plan,
Future Land Use Element). See the NRPA timeline (starting on page 15) later in this report for
more details on the NRPA history.
Clam Pass is a small, marginally stable inlet that has migrated north and south along the shore
over the years. Prior to dredging, average water depths of Clam Pass were -2.5' to -1.0', and its
width ranged from 30-50' (Collier County, 1994). The Pass remains the primary source of tidal
exchange for the Clam Bay system, but it is restricted by sediment deposits just inside the pass
and in the long meandering tidal creeks surrounded by mangrove forests.
6
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay ServiAprilces DiviVer., 4sion
242014.4
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Approximate extent of Clam Bay NRPA boundary.
Clam Bay NRPA Vital Statistics
Total acres: Approx. 570 acres
Beaches: A. 5,000 feet
Beach Park:Approx. 35 acres
Mangrove:Approx. 420 acres
Open Water:Approx. 115 acres
Latitude and Longitude of Pass:N 26° 13' 11", W 81°49' 01"
Section, Township, Range: Sec. 32& 33,Twp 485,Rng 25E,&
Sec. 4, 5, 8, &9,Twp 49S, Rng 25E
Water Body Identifipation(WBID) 3278Q1
7
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
Adjacent Communities
The Clam Bay NRPA is bound on the north by Vanderbilt Beach Road and the Bay Colony
portion of the Pelican Bay development; to the south by Seagate Drive, and the Seagate and
Naples Cay developments; to the east by the Pelican Bay development; and to the west by the
Gulf of Mexico and the Strand neighborhood of the Pelican Bay development.
Pelican Bay is predominately a residential community consisting of private single-family homes,
villas, and both high and low-rise condominium units. The community also includes a 27-hole
golf course, common areas with meeting rooms, tennis courts, beach park facilities, emergency
services facilities, and commercial areas with shopping and hotels. The 2,104-acre Planned Unit
Development (PUD) was approved in 1977 as a partnership between Collier Enterprises and
Westinghouse Communities. It was one of the first developments in Florida required to save
fragile coastal wetlands and associated ecosystems (Urban Land Institute, 1981). The
development of Pelican Bay had a limited impact on the wetlands themselves with
approximately 94 acres, including about 78 acres in the northwestern corner of the property,
being developed. This left the majority of the mangrove forest intact and preserved around the
bays. As mitigation for these wetland impacts, the 570 acre preserve area, including the 35 acre
beach park, was donated to Collier County and eventually became the NRPA which is in place
today.
Development of Pelican Bay required a stormwater management system designed to spread
runoff along the eastern edge of the Clam Bay estuary (Collier County Report 1996). A four to
six foot high and 2 %2 mile long berm separates the developed portion of Pelican Bay from the
estuary lying to the west of the development, but numerous culverts through the berm discharge
water to a swale system along the eastern perimeter of Clam Bay. The eastern edge of Pelican
Bay is about 12-14 feet above sea level at US 41, sloping in an east-west direction to about 2 feet
above sea level near the berm. Six drainage basins operate on a gravity system to slowly move
surface water into the receiving area of Clam Bay.
Naples Cay is a high rise development consisting of 8 multi-story condominium buildings. The
community also includes pools, tennis courts, approximately 33 acres of park and preserve areas,
and two canoe and kayak launching piers. Construction on the first building in Naples Cay
started in the late 1970's, and the last building was completed in 2002. Stormwater management
is accomplished through several internal detention areas before water flows into Outer Clam
Bay.
The Seagate community is composed of about 80 single family residences. The community was
first laid out in the 1950's and still has a few undeveloped lots. Because development of this
community occurred so early, there was no community-wide stormwater management system.
More recent improvements to the road and utility systems have allowed for some dry retention
and sewerage improvements to be put in place. Many of the homes within Seagate were built
with boat docks along the communities man-made canals. Some homeowners keep motorized
vessels at these docks. The 1995 Manatee Protection Plan acknowledges that access and use of
Clam Bay was limited due to the shallow nature of the bay and ephemeral conditions associated
8
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
with the Pass. Seagate is the only community adjacent to the Clam Bay NRPA that is allowed to
have motorized vessels and the associated docks. Vessels are generally shallow drafted and their
access is limited by the day to day conditions of the Pass and connecting waterway.
Clam Pass Park is a 35-acre County park providing beach access on the south side of Clam Pass.
The park is wholly contained within the NRPA boundary. Access to the park is via a boardwalk
through the mangroves from the parking lot at the very southern end of Pelican Bay. Operation
and care of the Park is done under the supervision of the Collier County Parks and Recreation
Department. Through an agreement between the County and the Waldorf Astoria Hotel,much of
the day-to-day operation of the park is subsidized by the hotel.
Natural History
Prior to development the entire coastline of south Florida would have resembled the Clam Bay
ecosystem with meandering mangrove-lined shallow waterways buffering sandy barrier islands
and natural terrestrial communities. Unique within the heavily developed coastal community of
Collier County, the Clam Bay estuarine system is a valuable resource for wildlife (particularly
juvenile marine species and birds) as well as residents and visitors to the area who enjoy the
recreational opportunities the system offers such as photography, canoeing, kayaking,
paddleboarding, fishing,walking, swimming,bird watching, and beach going.
The system is a mixture of mangrove-lined tidal creeks, mangrove forests, shallow bays and tidal
passes, seagrass beds, tidal flats, sandy beaches and brackish interior wetlands. It consists of
approximately 420 acres of mangroves and some 115 acres of shallow, open water bays, as well
as a 35-acre beachfront parcel (Clam Pass Beach Park) and approximately 1.5 miles of sandy
beach.
A man-made water management berm now divides natural and developed portions where
historically mangrove forest would have transitioned gradually into the mesic coastal hammocks
and upland pine scrubs that made up the now developed portions of the Pelican Bay community.
A brief overview of these important habitat types, their key characteristics and value is provided
in the Resource Description Section(Section 3.0)of this Management Plan.
Historical Overview
Historically, Clam Pass was a small part of a large system of relatively shallow waterways and
interconnecting wetland communities extending from Lee County to Doctor's Pass. Anecdotal
evidence suggests that canoes and shallow drafted skiffs were used within many of these
interconnected areas.
Within the Clam Bay system, four Indian shell mounds have been identified and listed on the
Florida Master Site Inventory as Clam Bay Shell Ridge, Inner Clam Bay Shell Mound, Brackish
Hammock and Bayhead Camp (Hartwell, et. al, 1994). Based on the number of archaeological
sites documented within the NRPA boundary and the adjacent areas which have been developed
9
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
as the Pelican Bay community, this area was used extensively by native peoples before the
arrival of later settlers.
During the 1950's this system was isolated from adjacent mangrove lined creeks and bays by the
construction of Seagate Drive to the south and the construction of Vanderbilt Beach Road to the
north. The practical effect was to leave Clam Pass as Clam Bay's only connection to the Gulf.
The Clam Pass opening has moved over its lifetime up and down the shoreline, influenced by
major storm events and by man's alteration of the tidal prism and drainage basin that feeds the
Pass. A detailed discussion of the Pass, as well as aerial photographs of the Pass over time, is
provided in Section 3.0 of this Management Plan.
To properly understand and successfully implement proposed management objectives, actions
and events which have lead to the current situation in Clam Bay should be described. The time
lines presented later in this section are intended as background information and as a factual
recount based on anecdotal evidence,press reports,published and unpublished reports.
Mangrove Die-off and Restoration
The first mention of stressed or dying mangroves within the Clam Bay NRPA came from a 1978
Tropical Biolndustries and Gee and Jensen report titled Carbon Flows in Portions of the Clam
Pass Estuarine System, Collier County, Florida. Reports of stressed or dying mangroves
continued through the 1980's and 90's. In 1995, a large area of dead and dying mangroves was
documented encompassing approximately 42 acres adjacent to Upper Clam Bay (Turrell, 1996).
By 1999 this area had expanded to approximately 50 acres (Turrell, 2000).
The Clam Bay Restoration and Management Plan (CBRMP)was finalized in 1998 to address the
mangrove die-off. The major objective of the plan was to restore the dead mangrove area
through improvements to the tidal flushing capabilities of the system, including enhancements to
tidal flow into and out of the mangrove forest areas. This was accomplished through the
dredging of Clam Pass and portions of the interior channels within the system, as well as
construction of a network of hand-dug flushing channels throughout the original die-off area and
a few other areas that were exhibiting stress.
In the fifteen years following the implementation of the CBRMP the mangrove forest has
undergone a substantial recovery with over 90% of the original die-off area re-vegetated with
new mangrove growth.
Time Line of Important Events Within the Clam Bay System
1920
A dirt road is built by Forest Walker running from the north-east to south portion of Pelican Bay,
a forerunner of US 41.
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April 24,2014
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1950
Clam Bay ecosystem is part of a connected system of barrier islands, mangrove forest, passes
and waterways. The orientation of the beaches and passes would have changed seasonally and
with storms.
1952
Vanderbilt Beach Road is constructed, eventually severing connection with the Wiggins Pass
system to the north.
1958
Construction of Seagate Drive is completed severing flow into and out of the mangroves swamps
to the south. This area was subsequently dredged and excavated to become Venetian Bay.
.- -:r w..- - OSM—tL-9— �±:, . ..e, -- •..,a ,,r-�,«,�.y ,.
Vanderbilt Lagoon
it
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Out Clam Bay
} Upper Clam Bay
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Venetian Bay
Circa 1952 Aerial Photograph Circa 1960 Aerial Photograph
1972
Tri-County Engineering produces reports:
• An Ecological Study of the Clam Pass Complex is published by Humm&Rehm
• Hydrographic Investigation of the Clam Bay System
Coral Ridge-Collier Properties, Inc. (a partnership between Westinghouse and Collier Properties)
acquired the property and initiated development of Pelican Bay.
1974
Pelican Bay Improvement District is formed to manage common property in Pelican Bay and
provide for long term sustainable infrastructure.
1976
Three, bi-directional 24-inch culverts are placed under Seagate Drive to provide hydrologic
connection to Venetian Bay.
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
Report"Environmental Assessment for Development Approval" is prepared for Pelican Bay.
Clam Pass closed and was mechanically dredged by dragline to re-open the entrance; no records
of quantities or dredge limits are available.
1977
Pelican Bay Planned Unit Development is approved, and construction commences.
1977-1979
Gee & Jensen Hydrographic Engineers conduct a series of tidal studies within the system and
distribute"A hydrographic study of Clam Bay system" in 1978.
1978
Tropical Bio-Industries produce a report: Carbon Flows in portions of the Clam Pass estuarine
system.
Ecological assessment work by Tropical Bio-Industries for permitting of the north-west fill area,
notes a small area of stressed and dead mangroves close to Upper Clam Bay.
1979
Environmental Assessment of the northwest fill area is distributed.
Tropical Bio-Industries produce biological reports:
• A comparative study of the water and carbon flows of Upper Clam Bay
• Invertebrate Population Studies in the vicinity of Upper Clam Bay
1981
Clam Pass closed and was mechanically dredged by dragline to re-open the entrance; no records
of quantities or dredge limits are available.
WCI, the developers of Pelican Bay, transferred title to Clam Bay to Collier County with the
stipulation that Clam Bay shall remain a conservation/preservation area in perpetuity.
1982
WCI deeded Clam Pass Park and Clam Bay to Collier County and in accordance with the Pelican
Bay PUD, required the County to seek approval of WCI or its successors for any modifications
to Clam Bay.
1983
Tropical Bio-Industries produce biological reports:
• Fish populations of tidal ponds west of Upper Clam Bay
• Populations of Melampus coffeus (Coffee bean snail) and Cerithidea scalariformis (Ladder
hornsnail)west of Upper Clam Bay
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April 24,2014
Ver.4.4
1986
Collier County constructs a 2,900' boardwalk to provide access to the county park, south of Clam
Pass.
1988
Clam Pass closes twice, first in the spring and again in the late fall after Tropical Storm Keith
(November 23, 1988).
1989
Small areas of stressed and dying mangroves are noted by residents in the basin west of Upper
Clam Bay and east of The Strand in Bay Colony. A Department of Natural Resources (DNR)
interdepartmental memo highlights cause of the stress as "the lack of adequate water circulation
resulting from the closure of Clam Pass".
First emergency dredging permit received from DNR to re-open clogged Clam Pass, following
memo by David Crewz to the DNR highlighting problems and danger if the Pass was not re-
opened.
Clam Pass was mechanically dredged to re-open. Approximately 700 cubic yards of material
were removed from the mouth of the inlet and the south bend of the channel. Material was
placed south of the Pass. Multiple closures of the inlet occurred during the construction process.
1990
Pelican Bay Improvement District becomes a dependent district of Collier County called the
Pelican Bay Services Division (PBSD).
1992
The area of dead mangroves is reported at 7 acres.
1994
20 acres of mangroves are reported dead.
1995
Clam Bay is approved by the Board of County Commissioners as Collier County's first Natural
Resource Protection Area(NRPA).
Clam Pass closes following a winter storm event. Emergency dredging permit issued allowing
opening of the Pass, but no work farther back than 600 feet. Mechanical dredging is undertaken
removing approximately 5,000 cubic yards of material from the entrance of the pass.
1996
Clam Pass closes following a winter storm event. Permits to open Clam Pass received from the
Florida Department of Environmental Protection (FDEP) (formerly DNR) and US Army Corps
of Engineers (USACE). Mechanical dredging event carried out at the entrance of the Pass.
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
In summer and fall blasting of an interconnecting waterway and hand excavation of flushing
channels were permitted and completed in 1997.
Mangrove die-off area estimated at 50 acres.
1997
Clam Pass, on the verge of closing following a winter storm event, is mechanically dredged
again under modification to 1996 Permits. Interior portions of the flood shoal were dredged to
keep the Pass open.
1998
Clam Pass was on the verge of closing again following a winter storm event. A mechanical
maintenance dredging event was carried out under modification to 1996 Permits. Interior
portions of the flood shoal were dredged to station 6+10.
Ten year permits received from FDEP and USACE for dredging Clam Pass and the interior
channels. Included adjustments to the Seagate culverts and installation of hand dug channels
throughout the system. Associated monitoring work and storm and freshwater studies were
required.
1999
Dredging work associated with the CBRMP was implemented (Mgmt by PBSD) in the spring by
Ludlum Construction Company. Hydraulic dredging of Cuts 1, 2, 3, and 4 were carried out. A
30 foot entrance cut was dredged.
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One way flap valves installed on. Seagate culverts to allow flow from south to north.
Staff at The Conservancy of Southwest Florida commences a 3-5 year study of mangroves,
surface water level and elevation within the mangrove die-off area.
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CLAM BA YNRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
2000
Hurricane Gordon impacts the area with no inlet closure.
2002
Hydraulic maintenance dredging of Clam Pass flood shoals between stations 3+10 and 18+00
(Mgmt by PBSD) completed to improve tidal circulation. The entrance of the pass was not
dredged during this event.
Flap valves on Seagate culverts removed due to insufficient head differential causing them to act
as plugs instead of valves.
Canoe trail markers permitted and installed throughout Clam Bay system.
2004
Hurricane Charley passes approximately 30 miles west of Clam Pass. A lot of sand was
redistributed but the Pass did not close. Extensive limb and leaf loss was documented within the
mangrove forest.
2005
Hurricane Wilma comes ashore about 30 miles south of Clam Pass. More limb and leaf loss is
noted. Pass did not close.
- 4
Hurricane damaged mangroves along bay 2005 Same mangroves along bay 2007
2007
Hydraulic maintenance dredging of Pass and entrance channel was conducted between Stations 0+00
and 18+00. The entrance of the Pass was dredged at 80 foot width. (Mgmt by Collier County Coastal
Zone Management Dept.).
2008
Tropical Storm Fay comes ashore about 30 miles south of Clam Pass. The area received over 10
inches of rainfall. Pass not affected.
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
2009
1998 FDEP and USACE permits for maintenance of the Pass expired after 1-year extensions.
2010
Permits issued to continue maintenance of hand-dug flushing channels throughout the system.
2011
White mangrove die-off was observed in central portion of the system and found to be caused by a
bark beetle infestation of trees that had suffered cold temperature stress.
Benthic Habitat Assessment study completed within the Clam Bay NRPA by the Conservancy of
Southwest Florida. Study provides comprehensive mapping of benthic habitat compositions and
distribution throughout the Clam Bay NRPA.
2012
Canoe trail markers and informational signage installed throughout Clam Bay.
The mouth of Clam Pass moves to the north near the Pelican Bay Beach Store. The northern shoreline
of the Pass is temporarily reinforced with the installation of concrete barriers.
Impacts from tropical storms Debby and Isaac, along with numerous winter storm fronts caused the
closure of the Pass.
2013
A single event mechanical dredge is carried out in March under FDEP and USACE permits with an
entrance cut of 45 feet. Beach compatible material is placed north and south of the pass above the
mean high water line.
Development of a new Management Plan is initiated through stakeholder input and multiple public
meetings.
Time Line specific to the establishment of the Clam Bay NRPA
1976
Collier County Ord. 76-30 zoned coastal areas environmentally sensitive lands as ST(Sensitive
Treatment)
1977
Approval of the Pelican Bay PUD (Ord. 77-18)by Collier County. The PUD identified 98 acres of
coastal mangrove wetlands to be filled in for development while preserving 570 acres of ST lands as
the Pelican Bay Conservation Area. (35 acres in the south and 5 acres in the north would become parks
providing public beach access).
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
1981-82
Department of Army Permit(79K-0282) authorized the fill of the 78 acres of coastal wetlands(76
acres for residential development and 2 acres for public parking area).It required 570 acres including
Upper, Inner, and Outer Clam Bays, and their adjacent wetlands to be conveyed to Collier County and
to remain a conservation/preservation area in perpetuity for the use of the public. It also prohibited
dredging Clam Pass except to keep it open to the Gulf of Mexico.
1988
The Pelican Bay Conservation Area(570 acres)was approved and recorded as FL-64P by Congress
and became part of the Federal Coastal Barrier Resources System (CBRS).
1995
The Collier County Board of County Commissioners approved the County Natural Resources
Department's recommendation to establish the County's first Natural Resource Protection Area
(NRPA); stipulating that that it would have the same boundaries as the Pelican Bay Conservation Area
within the Pelican Bay PUD.
The Collier County Manatee Protection Plan is approved. It contains the recommendation to establish
an"Idle Speed/No Wake"zone throughout the Clam Bay/Clam Pass System.
1996
Collier County Ordinance 96-16: "The Clam Bay System Water Safety and
Vessel Control Ordinance" is approved. It establishes that the Clam Bay System is an"Idle Speed/
No Wake"zone.
1998
The Clam Bay Restoration and Management Plan(CBRMP) is developed, implemented, and managed
by the PBSD and their consultants.
FL Admin. Court Case No. 98-0324GM provided an interpretation that certain elements of the Collier
County Growth Management Plan(Conservation and Coastal Management Element)require protection
of habitats within NRPAs which support existing and potential uses by wildlife.
2008
Public Law 110-419 was adopted identifying the Coastal Barrier Resource System, Clam Pass Unit,
FL-64P to be entirely located within the existing boundaries of the Clam Bay NRPA.
2013
Work begins on new Clam Bay NRPA Management Plan under PBSD direction.
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
3.0 Resource Descriptions
Soils
Based on the National Resource Conservation Service (NRCS) "Soil Survey of Collier County Area,
Florida" (NRCS, 1998) there are 2 different soil types (soil map units) present within the NRPA
boundary.
It is important to understand that where the soil survey shows mapping units named for soil series, the
units represent the dominant undisturbed soils in that landscape that existed predevelopment. The unit
descriptions do not recognize or appropriately interpret the drastically disturbed nature of urban
landscapes created after the soil survey was completed.
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Durbin and Wulfert mucks, frequently flooded (Map Unit #40), covers approximately 66% of the
NRPA. These level,very poorly drained soils are most often found in association with tidal mangrove
swamps. Mapped areas can consist entirely of either Durbin or Wulfert or any combination of the two
soils. Individual areas are elongated and irregular in shape and range from 50 to 1000 acres. The
slope is 0 to 1 percent. The permeability of the Durbin soil is rapid and the available water capacity is
high. The permeability of the Wulfert soil is rapid and the available water capacity is moderate. The
water table fluctuates with the tide and is within 12 inches of the surface most of the year. The soil is
subject to tidal flooding. The natural vegetation within these areas consists of red, white and black
mangroves.
Canaveral-Beaches Complex(Map Unit#42) covers approximately 9%of the NRPA.
This map unit consists of the nearly level, moderately well drained Canaveral soil on low ridges and
beaches. Individual areas are elongated and irregular in shape and range from 20 to 300 acres. The
slope is 0 to 2 percent. Typically, beaches consist of sand mixed with shell fragments and shells and
are subject to frequent wave action. The permeability of the Canaveral soil is rapid to very rapid. The
available water capacity is very low. In most years, the seasonal high water table is at a depth of
between 18 to 40 inches for 1 to 4 months. This soil is subject to tidal flooding under severe weather
18
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
conditions. Natural vegetation consists of sea oats, sea grape, cabbage palm, and salt grasses. They are
commonly invaded by exotics such as Australian pine and Brazilian pepper.
Topography
Topography is shown below using a Light Detecting and Ranging map (LIDAR)obtained from Collier
County. The elevations within the NRPA boundary range from +5.0 to -7.0 NAVD88. The
surrounding lands are generally higher than the NRPA and generate the freshwater flows into the
preserve.
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
Climate
Clam Bay's climate falls within the USDA subtropical classification. There are essentially two
seasons experienced. The wet season occurs in the summer, and the dry season occurs in the winter.
Typical rainfall and temperature data are provided in Tables 4.1 and 4.2.
In the summer the center of the trade winds shift north and moisture-laden breezes blow from the east
or south-east. In winter the trade winds shift southward and the winds are less constant. Weather is
then more influenced by fronts advancing from the northwest. This brings cooler conditions, although
temperatures rarely reach freezing, due to the fact that they are being moderated by the surrounding
waters. Cold fronts are typically preceded by winds from the southwest, which clock to the west then
northwest as the front passes,with strong winds of 20-25 knots and cooler air. In general terms,winds
are predominantly southeast during the summer and northeast during the winter.
Historical meteorology for Clam Bay is based on data collected for 30 years (from 1981 to 2010) from
the Naples Municipal Airport by the Florida Climate Center (NOAA & FSU). The following charts
present meteorological statistics for temperature and precipitation.
1981-2010 TEMPERATURE AND PRECIPITATION NORMALS GRAPH
110.0
100.0
90.0
70.0 •
60.0 {
0 R.sCh•5 F,
50.0
0.0
30.0
200_t1
1 0.0 ..
0.0
Jan Mar May Jul Sep Nov
4 Precip (in) 0 Min Tmp (`F) 0 Avg Tmp (`F) 0 Max Imp (T)
Table 4.1
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
Temperature
The monthly average temperatures range from 64.5°F to 83.2°F. The lowest monthly minimum
temperature is 54.2°F while the highest monthly maximum temperature is 91.2°F. The data reflect a
humid subtropical climate with a narrow fluctuation in air temperature.
Precipitation
Average annual rainfall for the Naples Municipal Airport NOAA station is documented at 51.89
inches. The data in the table indicates the highest rainfall occurs during the summer months of June,
July,August, and September.
1981-2012 TEMPERATURE AND PRECIPITATION NORMALS CHART
0 Precip tin) 0 Min Trnp(°F) 0 Avg Tmp(°F) O Max Trap(°F)
January 1.55 54.2 •
64.5 74.7
February 2.10 56.8 •
66.9 76.9
March 2.38 60.0 70.0 79.9
April 2.36 63.4 73.3 83.2
May 316 68.5 78.2 ' 87.8 •
June 8.82 73.9 81.9 89.9
July 7.27 749 83.1 1 912
•
August 8.58 75.3 83.2 91.0
i
• September 7.69 74.8 82.4 89,9
October 4.19 70,0 78.5 86.9
November 2.04 62.9 72.1 81.2
December 1.45 57.0 66.8 76.6
Table 4.2
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CLAM DAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
Winds
Winds are predominantly easterly throughout the year, but with a tendency to become northeasterly
from October to April and southeasterly from May to September. Wind speeds, not including storm
events are, on average, below 10 knots. During the winter months when fronts move through, for a
day or two at a time,winds out of the northwest to northeast may increase to about 25 knots.
Sea breeze
As the land surface around Naples and Clam Bay warms, the air above is heated. The warm air is less
dense and tends to rise creating a lower air pressure over the land than the water. The cooler air over
the water then flows inland creating a sea breeze. In the evening the reverse occurs and the cooler air
over the land will flow back toward the water creating a land breeze.
The incoming sea breeze acts as a lifting mechanism, resulting in the warmer air rising up to higher
altitudes. This creates cumulus clouds that begin to build which leads to the development of afternoon
showers and thunderstorms in the area.
Storms
Naples and Clam Bay specifically are within the Atlantic Tropical Cyclone basin. This basin includes
much of the North Atlantic, Caribbean Sea, and the Gulf of Mexico. On average, six (6) to eight (8)
tropical storms form within this basin each year. The hurricane season lasts from June 1st to December
1st. The formation of these storms and possible intensification into mature hurricanes takes place over
- - warm tropical and subtropical waters. Eventual dissipation or
Safflr-Simpson Hurricane Scale modification, averaging seven (7) to eight (8) days later, typically
Category Wind speed Storm surge
occurs over the colder waters of the North Atlantic or when the
mph 1t storms move over land and away from the sustaining marine
(km/h) (m)
Flue x'156 >18
environment.
(>250) (>5.5)
131-155 13-18
Four Due to the destructive nature of these storms, landfall can result in
(210-249) (4.0-5.5) significant damage to upland development and facilities from storm
Three 111-130 9-12
(178-209) (2.7-3.7) surge, waves, and wind. A good example of this would be
96-110 15-8 Hurricane Wilma which formed in 2005.
Two
(154-177) (1,8-2.4)
One 74-95 4-5 A tropical storm is defined by maximum sustained winds from 35-
(119-153) (1.2-1.5) 64 knots (40-74 mph). A hurricane has maximum sustained winds
Additional classifications that exceed 64 knots (74 mph). Hurricanes are classified into
Tropical 39-73 o-s different categories according to the Saffir-Simpson scale.
storm (r�"11 ) (0-09) ' Hurricanes can also spawn severe weather such as tornadoes as they
° I move inland.
The table below lists the number of tropical storms and hurricanes
that passed through or near Naples over the past 20 seasons including 1992 through 2012 as reported
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April 24,2014
Ver.4.4
by the National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center and
Hurricane City (www.hurricanecity.com). Analysis of the available information indicates that Naples,
on average, is brushed or hit by a tropical storm or hurricane once every 2.71 years and is directly hit
once every 7.05 years.
Table 4.4 Number of Named Storms Passin• throu•h or near Na•les
Year #of Storms Names Strength closest to Naples
1992 1 Andrew Hurricane Cat.3
1993 0
1994 1 Gordon Tropical Storm
1995 1 Jerry Tropical Storm
1996 0
1997 0
1998 1 Mitch Tropical Storm
1999 1 Harvey Tropical Storm
2000 1 Gordon Tropical Storm
2001 0
2002 0
2003 0
2004 1 Charley Hurricane Cat.3
2005 1 Wilma Hurricane Cat.2
2006 0
2007 0
2008 1 Fay Tropical Storm
2009 0
2010 0
2011 0
2012 0
2013 0
Hurricane Wilma image
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
Natural Communities
In this Section, a natural community refers to the mix of plant and animal species that form the natural
basis of the Clam Bay NRPA. A combination of factors including geology, climate, hydrology, soils,
and anthropogenic influences determines the specific types of plants found in any given area. These
plants are a major factor in what type of animal species that may be present. The Florida Department
of Transportation's Land Use, Cover,and Forms Classification System(FLUCFCS 1999)has been
used to identify the plant communities found within the Clam Bay NRPA.
FLUCFCS Community Description Upland or %of Clam Bay
Code Wetland NRPA
181 Swimming Beach Upland 5.95
186 Community Recreation Facilities Upland 0.40
322 Coastal Scrub Upland 3.98
428 Cabbage Palm Hammock Upland 0.45
540 Bays (with and without direct Wetland 23.16
connection to Gulf or Ocean)
612 Mangrove Swamp Wetland 64.60
642 Saltwater Marsh Wetland 0.04
651 Tidal Flat Wetland 1.44
911 Seagrasses** Wetland 0.84**
** included in the Bays (541)category
Several other components of the Clam Bay NRPA ecosystem are also addressed below. These
components include offshore hardbottom, oyster and other benthic faunal communities that are not
specifically addressed in the FLUCFCS classification system. Additional historical information on the
Clam Bay mangrove and seagrass habitats is included as appendices to the Plan.
FLUCFCS Code 181 - Swimming Beach
Beaches form when offshore sand deposits are moved landward by wave action usually during the
spring and summer. Sand, which is stirred up as the wave breaks on the shore, drops out of suspension
as the water moves up the beach face. Thus, the beach becomes gradually higher, wider, and steeper.
In the wintertime, larger, higher energy waves associated with winter storms overflow the beach area
and stir up the sand deposited earlier in the year. The sand is pulled off the beach as the wave recedes
and is deposited in an offshore sand bar. If these two forces are in equilibrium, the beach area will be
stable from year to year. However, naturally occurring factors such as storm events, littoral drift
(lateral movement of sand because waves approach the beach at an angle), and offshore winds, upset
this equilibrium and result in the ever shifting nature of the beach environment.
Dunes form because of onshore wind action on beach sand. When wind speeds are sufficient,
individual grains of sand start to roll and bounce along the surface. This windborne sand is transported
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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April 24,2014
Ver.4.4
landward until the wind speed drops below that needed to move the sand. Coastal vegetation is critical
for slowing wind speeds and causing sand to be deposited.
Landward of the highest tides, pioneer or frontal zone sites are stabilized by sand trapping action of
various rhizomatous grasses and low growing shrubs that are tolerant of salt spray. Only a few plant
species can tolerate the stresses of a dune environment, particularly frontal dune sites. Foredune plants
must be able to survive being buried by blowing sand, sand blasting, salt spray, salt water flooding,
drought,heat, and low nutrient supply. Coastal plants colonizing the dunes are key players in trapping
windblown sand and preventing coastal erosion as the first defense against heavy winds and surge of
tropical storms.
Many plant species that occur on dune areas have developed specific attributes to help them survive these harsh
environments. These include high growth rates, dense root systems, low profiles, and high flower and ed
production rates. Species common on the beaches of the Clam Bay system include; Sea oats (Useniola
paniculata), Seagrape(Coccoloba uvifera),and Railroad vine (Ipomoea pes-caprae). See page X for a
more complete list of common plant species found in this habitat.
There is approximately 8,675 linear feet of shoreline within the Clam Bay NRPA in three distinct
segments separated by the two Pelican Bay Foundation beach facilities. Contiguous beach habitat
extends from the NRPA habitat both north and south along the coast. Shorebirds feed on marine
invertebrates such as coquina clams and mole crabs at the water's edge and beaches are crucially
important habitat for nesting sea turtles.
This particular habitat has been monitored periodically in terms of width as part of the Collier County
Beach renourishment program though no conclusive statements can be made about the floral or faunal
details of the ecotone over the years. Large scale generalizations based on the annual aerial
photographs can be made that the overall size, composition, and health of the habitat have remained
relatively stable and, with the exception of the areas immediately adjacent to the Pass, are mostly
unaffected by the status of the Pass.
4
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Beach habitat within NRPA Boundary
25
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
FLUCFCS Code 322 - Coastal Scrub
Landward of the frontal (Beach)zone area is the back dune zone (also often called the coastal shrub or
scrub zone), a portion of the dune that is more stable, has greater organic matter, and supports less salt
tolerant grasses and shrubs as well as some trees.
Many of the woody species found in coastal scrub are low growing and shrubby due to low nutrient
and droughty conditions of sandy soils. High winds and salt spray often prune the terminal buds of the
trees and shrubs growing on the dunes and result in salt-pruned,windswept canopies.
Coastal scrub is represented by a conglomeration of coastal species generally found in a narrow band
between the Mangrove forest and the beach areas. Species common in the coastal scrub zone of the
Clam Bay system include; Seagrape (Coccoloba uvifera), Cabbage palm (Sabal palmetto),
Buttonwood (Conocarpus erectus) and Spanish bayonet(Yucca aloifolia). This is an important habitat
as it helps anchor the back dune sands and provides habitat for several listed plant and animal species
including the gopher tortoise (Gopherus polyphemus). See page X for a more complete list of common
plant species found in this habitat.
The primary management issues of concern in the coastal scrub are gopher tortoise habitat
management and exotic vegetation control.
14
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26
CLAM BAYNRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
Apr1.2v4.:::2:4.t4.1 14
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FLUCFCS Code 428 - Cabbage Palm Hammock
This forested zone is composed of the more protected dune vegetation farthest from the Gulf of
Mexico. The Cabbage Palm Hammock habitat is identified by the preponderance of cabbage palms
(Sabal palmetto). It is generally found in pockets located between the mangrove forest and the coastal
scrub zone or beach areas. Aside from the cabbage palms, sea grapes (Coccoloba uvifera),
buttonwood (Conocarpus erectus), and several other hammock species such as wax myrtle (Myrica
cerifera) and myrsine (Myrsine guianensis) are common. A hammock is a habitat that is densely
shaded by a canopy of trees. Hammocks usually have a sparse groundcover that leaves the forest floor
mostly open for animals to travel through. Hammocks also provide a reprieve from the sun for animals
and humans alike. In Clam Bay, this habitat is also susceptible to infestation by exotic vegetation such
as Australian pine (Casurina equisetifolia) and Brazilian pepper (Schinus terebinthifolius) which are
addressed further on(in this Section.
The primary management issues for this habitat are exotic control and preventing destructive visitor
•
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Cabbage Palm Hammock habitat within NRPA Boundary
27
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
FLUCFCS Code 540—Bays (with and without connection to the Gulf)
The Clam Bay NRPA contains the three larger bays associated with Clam Pass (Outer, Inner, and
Upper) as well as the interconnecting shallow creeks and small open water areas. Second in extent of
aerial coverage within the NRPA boundary, it is the bays and interconnections which serve as the life
blood of the estuary.
This open water habitat serves as the basis for many other communities. Seagrass beds, oyster bars,
clam beds, and other benthic communities can all be supported to varying degrees with the open waters
of the bays and interconnecting creeks. As outlined below, several of these communities are present
within the Clam Bay NRPA and will be considered when deciding on management activities outlined
within this Management Plan.
Multiple studies have indicated that the single most important thing that can be done to restore the
health of the Clam Bay system is to improve the total tidal flushing capacity of the system (Tackney
1996; Lewis 1996; Wilson Miller, et al 1996; Turrell 1996.). The dredging conducted within the Pass
and the interconnecting creeks, as well as the hand-dug flushing cuts, have been seen as the major
contributing factors to the restoration of the mangrove forest community within the system (Turrell
2008; Humiston&Moore 2003).
Tidal Pass
Clam Pass is the only open water connection to the Gulf of Mexico for the Clam Bay NRPA. The
exchange of seawater between Clam Bay and the Gulf is critical to the ability of the estuary to export
organic matter, as well as to help regulate excess salt and freshwater. It also supplies oxygen rich
water from the Gulf of Mexico. In the absence of surface water circulation or tidal activity, estuarine
habitats such as mangroves can slowly die due to deleterious changes in the sediment: 1) in the
absence of oxygenated water, the sediments become anaerobic or anoxic, and 2) metabolic wastes and
hydrogen sulfide accumulate in the anoxic sediment(CBRMP, 1998).
Tides in the Gulf of Mexico are mixed, with the norm being two high tides and two low tides
experienced per day and normal amplitude (range) of approximately 2 feet. The highest tides (springs)
are experienced twice per lunar month at full and new moons when the gravitational pull on the earth's
surface waters is greatest. Neap tides also occur twice per lunar month when the planetary
(gravitational) influences of earth, moon and sun are perpendicular.
28
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
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29
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
It can be seen that the health of mangrove forests is directly related to the efficiency of the tidal pass.
Clam Pass and its associated waterway is a very dynamic creek whose location has varied over time
(Turrell 1995; Tackney 1996). Because of this, it is susceptible to outside events and can periodically
close, such as has happened at least six times in the last 25 years.
The following aerial photographs show how the Pass and its waterway have changed over the past 60
years.
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30
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
..:'..,....1. , ..‘t -„,, . ,,,„
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Tidal creeks are passageways for fish and marine invertebrates between the open waters of the Gulf
and the protected embayments of Clam Bay. Manatees,dolphins and sea turtles may also use the Pass.
Scouring action of the fast flowing tide generally prevents colonization by seagrasses and other benthic
plants and the substrate is typically sand and shell with the finer sediments carried in suspension and
deposited just outside the mouth of the pass (the ebb shoal delta) or to the interior of the system on the
incoming(flood)tide.
Management concerns related to the bays and associated creeks include maintaining sufficient flow
through them to accomplish flushing needs of the system, stabilization of the Pass without harming
other components of the NRPA, and educating recreational users of the NRPA of the need to protect
the shallow water habitats and the communities located therein.
31
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
�zz� r t,, t S ,;js - -71i7.11;:::‘
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FLUCFCS Code 612—Mangrove Swamps (Forest)
Mangroves are salt tolerant trees that grow in tidal areas of the tropics and are legally protected for
their ecological value,with such functions as;
• Providing habitat for marine,terrestrial and avian wildlife.
• Protecting coastal areas from storm surges and coastal erosion.
• Improving water quality by acting as a natural filter for land based freshwater run-off
• Forming the basis of a highly productive estuarine food chain which includes many commercially
valuable species.
• Enhancing the atmosphere by absorbing carbon dioxide and reducing greenhouse gasses.
Approximately 65% of the Clam Bay NRPA is composed of the three common mangrove species in
Florida, namely red mangroves (Rhizophora mangle), black mangroves (Avicennia germinans), and
white mangroves (Laguncularia racemosa)make up the mangrove forests within the Clam Bay NRPA.
All three species have special biological adaptations to cope with salt and unstable, mucky, low
oxygen soils that result from the tidal,hence continually waterlogged, environment. The dominance of
mangroves in tidal areas is a function of these adaptations and their ability to out-compete other
wetland plants. Tidal flushing allows nutrients to be distributed within the forest and provides for the
transportation of dead leaves,twigs, etc. As this material decays, it becomes food for marine life. It is
this mangrove detritus which is consumed by the many organisms at the base of the food chain and
which in turn create the next level of the food chain necessary to support the fish populations that
characterize the mangrove community.
Special attention has been given to the mangrove community in the past because of the die-off which
occurred between 1991 and 1997 (though stress in the community was documented as far back as the
late 1970's). The die-off affected black and red mangroves initially but eventually ended up
encompassing some white mangroves as well. More details on the recent history of the mangrove
management are provided in Appendix 1 included with this plan.
32
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
Red Mangroves
Red mangroves (Rhizophora mangle) are recognized by their tangle of reddish looking prop roots, long
cigar shaped seedlings (propagules) and their large, pointed evergreen leaves. Red mangroves flower
all year but reach maximum propagule production during the late spring and early summer months.
They are typically the most seaward of the three species with the prop roots and vertical drop roots
providing support. Small pores on the trunks called lenticels allow oxygen exchange via air as the
waterlogged soils become rapidly oxygen depleted. Salt is excluded from the plants cells through a
process called ultra-filtration in the roots. The characteristic propagules germinate on the parent tree
and drop and float for up to a year, finally becoming heavier at one end so that when encountering a
suitable substrate they are ready to root upright. The mass of prop and drop roots forms extensive
surface area under water for attachment of sessile, filter feeding marine species (such as sponges,
tunicates and mollusks) as well as hiding places for juvenile fish. Birds, butterflies, insects and
mammals find home and food within the canopy.
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Red Mangroves and Propagules (inset)
33
CLAM BA YNRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
Black Mangroves
Black mangroves (Avicennia germinans) are typically found a little further inland. Key identification
features include the snorkel like pneumatophores which radiate upwards out of the soil from the base
of the trunk, a grey-black rough bark and slightly pointed, oval leaves which are silvery with salt
deposits on the undersides. The pneumatophores play an important role in oxygen exchange and
unlike the red mangroves, which keeps salt out of body cells through filtration in the roots; the black
mangrove excretes salt out of the backside of the leaves. They are also reliant on adequate tidal
exchange but lack the supporting prop roots that typify the red mangrove. Small white flowers and
lima bean shaped propagules are typically apparent during the late spring and early summer months.
Black mangroves are cryptoviviparous as the embryo develops within the fruit while on the parent
plant. When these propagules fall from the parent tree, they are able to float for a short period before
rooting in the mucky soil.
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Black Mangrove Pneumatophores
34
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
White Mangroves
White mangroves (Laguncularia racemosa) are the third mangrove species and are often found further
inland than the other two species (although zonations described are typical they can frequently vary).
Since they often occur in drier areas, white mangroves do not exhibit the adaptations to soft, anaerobic
soil of the other species. The bark is characteristically grooved and furrowed and leaves are oval, mid-
green and leathery with two small glands on the petiole at the base of each leaf. White mangroves also
flower in the spring and early summer and the small seedlings have the shortest floating dispersal stage
of the three species. White mangroves are semi-viviparous and germinate inside the fruit during the
approximately five day dispersal,but not while attached to the parent plant
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35
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
The mangrove communities are composed of both riverine (along the creeks) and basin forest
components. The species composition of mangroves within these two community components is very
distinctive. Riverine mangrove areas are almost exclusively composed of red mangroves within the
Clam Bay NRPA while all three species, along with buttonwood(Conocarpus erectus) are found in the
forest component.
Riverine (Creeks)Mangroves
On the waterward edges of small islands and the tidal creeks, passes and estuarine waterways that
make up the Clam Bay system, a fringe of red mangroves will be found growing up to 25 feet in
height. This zone can be just one or two trees in depth or extend landward for some distance,
depending on topography. The habitat provided by the prop roots of these red mangroves is of great
importance to many fish and other aquatic organisms.
Forests
The majority of the Clam Bay mangrove habitat is low-lying basin forest where the dominant
mangrove species varies between red, white, and black throughout the forest habitat. This forest
community was the habitat affected by the mangrove die-off. The hand dug flushing channels were
constructed throughout this community to increase the flushing capacity through tidal inundation.
Associated plants within the mangrove habitat include Buttonwood (Conocarpus erectus), the
succulent groundcovers Saltwort (Batis maritime) and Glasswort (Salicornia cervicornis), (especially
where a fallen tree provides a break in the canopy and light penetration to the forest floor) and, further
inland and closer to freshwater sources,the Leather fern(Acrostrichum danaefolia).
,,,,,,,,‘
>r K 1:1/4,74,44_, �i ? > r vr tbp.� tG9 ,,,„
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Mangrove habitat within NRPA Boundary
FLUCFCS Code 642- Salt Marsh
At the interface between forested mangrove areas and the water management berm are depressional
areas. that have become colonized by aquatic freshwater plants such as cattails (Typha latifolia),
Carolina willow (Salix caroliniana), Bulrush (Scirpus californicus), Needlerush (Juncus romerianus)
and Leather fern (Acrostichum danaeifolium). Wildlife such as otters (Lutra canadiensis), alligators
36
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
Pelican Bay Services Division
April 24,2014
Ver.4.4
(Alligator mississippiensis), various turtles, and wading birds can be commonly observed. These areas
require regular maintenance to prevent the spread of nuisance and exotic plant species and ensure
optimal functioning and interface between the natural mangrove forest and the development water
management system. 7c
r i c r r-S�,-4 i ' 7� 1r �1f `•.W.y,-ti-��is-r,: w.^� 1;1110 3 s'► * � j' -� �r"iS77+7F'. a'�'}r3,� ' iF-y., 1�1 Tlr[�{ii'("�ls a '>�vt.-mi--t.. a ',i ar y ff '' - ,,fi;11,, Ad). 7 z•� &te
'f lT4.i t ��';,�`M'" �as-.-Xj�Fl `S °4� 'Y��.F �M''+t'� #�` �, “, }+ ! .. �t`'i a �
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Salt Marsh habitat within NRPA Boundary
FLUCFCS Code 651 -Tidal Flats
Tidal flats are flat bottomed, sub- or intertidal habitats that lack an oyster or seagrass community and
are located inside the outer coastal margin. The two most significant environmental characteristics that
control a flat's infauna (benthic organisms that live within the substrate) and epifauna (benthic animals
that live on the surface of a substrate) are: the height of the substrate relative to mean sea level and the
sedimentary consistency of the substrate. The position relative to mean sea level dictates whether the
habitat is emergent (in air) for part of a tidal cycle or how deep below the water it is. This latter
characteristic controls other physical water quality measures, such as dissolved oxygen, the frequency
and duration of hypoxic events, and light penetration. Firmness of the substrate affects the capacity to
support an epifauna by both supporting the organism on the substrate and permitting the burrowing of
the infauna.
The sand and mudflats of Clam Bay are rich feeding grounds for many species of fish and wading
birds. These organically rich sediments support a variety of mollusks, worms and invertebrates that
scavenge detritus or, in the case of many bivalve mollusks, extend siphons at high tide and filter vast
quantities of water. Birds such as a variety of herons, ibis, egrets and spoonbills pick through the
sediment for the invertebrate food sources.
The dredging of the pass associated with the 1998 Restoration and Management Plan resulted in an
increase of exposed tidal flats within the southern portion of the system. Increased tidal range
resulting from the dredging allowed more area to be periodically exposed during the tidal cycle. Some
of the area that had supported seagrasses prior to the dredging work were converted into the tidal flats
by the increased range and reduced phase lag. Management concerns related to the tidal flats include
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CLAM BA YNRPA MANAGEMENT PLAN(DRAFT)
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the templates established for the dredging, the resultant currents that could be expected as a result of
dredging,and the frequency of disturbance.
- "-"r `.‘t-T.-1";—.4e- .7killtp .-„,:i, , :.; . sie .
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4.
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Tidal Flat habitat within NRPA Boundary
FLUCFCS Code 911 -Seagrass Beds
Seagrasses are flowering marine plants of shallow, tropical regions. With a. creeping growth form
connected by horizontal rhizomes they serve to trap and anchor sediment. Both the grass blades
themselves and the surface area they represent provide food and� attachment for marine species.
Seagrass beds are renowned for their value as nursery habitats and are legally protected.
Several areas within the Clam Bay system host seagrass beds, specifically Outer Clam Bay and
waterways just inside Clam Pass. Three species are commonly found in these Clam Bay waters; the
largest Turtle grass (Thalassic testudinum) with flat strap shaped leaves, the smaller shoal grass
(Halodule beaudettei (fka wrightii)) with narrow, flat blades and Paddle grass (Halphila decepiens)
with the smallest, paddle shaped leaves. Shoal grass is by far the most common though a small area of
turtle grass has persisted since the original 1998 dredging. Paddle grass is much more ephemeral in
nature and diligence is required to be able to locate it during the time frames when it is present.
rTe.
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Seagrass habitat within NRPA Boundary
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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•
r
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Shoal grass(Halodule beaudettei) along interior channel south of Clam Pass
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Paddle grass (Halphila decepiens) in center of Outer Clam Bay
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CLAM BA YNRPA MANAGEMENT PLAN(DRAFT)
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Ver.4.4
p` a�rz ��� � w :a ; °" �`a- i. r. z ¢, '"� :.
Turtle grass(Thalassia testudinum)just south of County boardwalk in Outer Clam Bay
Seagrasses rely on good light penetration to enable photosynthesis and are sensitive to reduced tidal
water quality. Growing in shallow regions they are also vulnerable to physical damage by boats. A
variety of marine algae can be associated with grass species, differing in the lack of a true rooting and
vascular system. Several species of both brown and green alga have been observed.
Seagrass coverage in Clam Bay has varied over time but has always been found predominately in
Outer Clam Bay and the waterway between this bay and Clam Pass. A 1994 Collier County report
estimated seagrass coverage at approximately 10 acres. Pre-dredge surveys conducted in 1999
estimated coverage at about 5.13 acres. Annual monitoring of seagrass beds along the monitoring
transects has estimated coverage from a low of approximately 1.2 acres in 2003 to the current estimate
of 2.85 acres from the 2013 survey. It should be noted that the coverage estimates are taken from
along the survey transects only and do not account for other scattered grasses that may be located
elsewhere in the system.
Management concerns related to seagrasses include direct impacts due to recreational use and potential
dredging templates,turbidity and water quality concerns related to flushing(too much or too little)and
stormwater inputs, and algal infestations due to nutrient increases.
A history of the seagrass monitoring efforts in Clam Bay is included in the Appendix 2 attached to this
report.
Other Benthic Habitats
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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Oyster Bars
Oysters (Croassostrea americana) are filter-feeding bivalves, which were once common within the
tidal creeks of Clam Bay (Humm and Rehm 1972). Oysters play a significant role in shaping the
environment in which they live by forming a hard structure upon which an intricate biological
community is built. Similar to coral reefs, oyster reefs are `biogenic' (formed by the accumulation of
colonial animals) and provide structure and surface area for numerous other temporary and permanent
species.
Providing complex habitat structure is the most fundamental of ecosystem services that oysters
provide. The structure provides a place for algae and non-mobile invertebrates to attach, as well as a
place for mobile invertebrates and fishes to be protected from predators. Although the relationships
between sportfish and oyster habitats are not as well studied as in other estuarine habitats such as
seagrass beds,they are considered essential fish habitat.
The numerous ecosystem services provided by oysters can be summarized into three general
categories: habitat provision, water quality improvement, and.shoreline stabilization. Oyster reefs
provide habitat to a diverse array of flora and fauna. The role of oyster habitat to the estuarine food
chain is highly significant, as discussed in the previous paragraph. Through their feeding process
oysters filter large quantities of water which transfers energy and material from the water column to
the benthic community, subsequently reducing turbidity and water column nutrients. Through bio-
deposition, nutrients are made available to the flora and fauna which comprise the complex oyster bar
food web. Additionally, oyster reefs stabilize sediments, shorelines and adjacent habitats by buffering
wave energy,further aiding water quality.
Deteriorating conditions related to closures of Clam Pass is thought to have resulted in the
disappearance of oyster bars in the system; though some re-occurrence has been observed to the south
of the pass in the last few years during seagrass transect monitoring. Oysters have been documented
around the perimeter of Outer Clam Bay in past years monitoring efforts.
OYSTER PHOTO
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CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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A 2011 benthic habitat assessment conducted by the Conservancy of Southwest Florida found living
oyster clusters in the upper reaches of Upper Clam Bay (a single cluster), in the tributary between
Outer and Inner Clam Bays (a single cluster), and throughout the shoreline of Outer Clam Bay.
Management concerns related to oyster growth are similar to the seagrass concerns, namely protection
from recreation users,water quality, and flushing.
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P.5 I P a',..g - ; C— `app -i
CLAM BAY NRPA MANAGEMENT PLAN(DRAFT)
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Ver.4.4
These mollusks are generally found within the shoal and tidal flat areas of the system and could be
susceptible to impact during dredging or other disturbance operations. Management concerns would
be protection from recreational users,water quality, flushing, and dredging.
n.tl =r" cry v%� �
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,per ,�=�" ] ':` ��c'" ,.�" = c
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' 'ri r`' i" — ` s p,"^iiT•1 S"a`tf'.. n. yi:� ' k 14 = .C'6
t,.12'ASC -1n ..t ;37 ai14 art !n' 'W W w•�l F 1.-`'
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+� ' " ., ,:,,k T� ".`` 4.0,124".-,,,,":.4.;1:',4M.'s 1 4"74-ate4 'T .i •, 9
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Exhibit from Conservancy of Southwest Florida Report
Tubiculous Polychaetes
Tubiculous polychaetes (tube worms) are typically the most abundant biological assemblage in Clam
Bay and are primarily associated with muddy and sandy substrates. Polychaetes, including worm tubes
and mud tubes, shell-encrusted polychaete tubes (Polychaeta) and trumpet worm (Pectinaria gouldi)
tubes are a vital component of the estuarine food web, providing key linkages between primary
producers and higher trophic levels. Polychaetes create habitat and food for many organisms such as
mollusks, fish and even sea turtles. These worms are usually filter or deposit feeders that keep the
substrate aerated and free of waste accumulation. Polychaetes tend to dominate Inner and Outer Clam
Bays, with lower occurrences in Upper Clam Bay, the Lower Tributary, and, to a lesser extent, the
Upper Tributary.
Hardbottom Communities
Another important marine habitat marginally associated with the estuarine system is the hard bottom
reef community found just seaward of Clam Pass. In about 10-15 feet of water a variety of sponges,
stony corals, gorgonians, fish and associated invertebrates can be found within a system of rocks and
ledges. Outcroppings of similar habitat type occur along the length of Collier County and are a little
known resource of regional significance.
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Ver.4.4
t'-
Hardbottom outcrop off of Clam Pass
Collier County has mapped this resource through side scan sonar surveys in 2005 and 2009 as part of
its beach renourishment project. The information received from the County shows that the landward
edge of this habitat is located approximately 250 to 300 feet offshore from the Pass.
"",f, 1 , , ! ,. �' 1f,+L.+ry , s=+ dye,_ ` ;c', . kj' r i ff�d". 1 �'
5 a ' (t■r' '1 f ..e,fi_` �°k(p w / r'7,, .r�,: ;'t % + '
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-'L az Ft OUTER 11
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Management concerns related to this habitat include recreation use and potential turbidity impacts
resulting from dredging or other management activities within the Clam Bay NRPA.
Invasive exotic,Non-native and Problem Species
In an ecological context,an invasive species is one that is aggressive in growth and expansion of range
and tends to dominate other appropriate native species. Its establishment and dominance can cause
widespread harm to an ecological system by altering the species composition, susceptibility to fire and
hydrology of an area. Non-indigenous species(i.e.,non-native or exotic species) are those that have
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Ver.4.4
been introduced purposefully or accidentally to an area outside their normal range. The characteristics
of some of these species (high rate of growth/reproduction, no natural predators, easily dispersed, able
to out-compete native species)make them invasive. Some indigenous species (a species whose natural
range included Florida at the time of European contact circa 1500 AD or a species that has naturally
expanded or changed its range to include Florida) may also become invasive. Invasions by native and
non-native species often follow an alteration to ecosystem function, disruption of the food web, large-
scale fragmentation of an ecosystem and/or disturbance (e.g., clearing, fire, drought, etc.) of an area.
While some native species may become invasive,the establishment and dominance of non-native
species is of particular concern. The exotic species documented within the NRPA and those that have
a potential to occur within the NRPA are discussed in the following section.
Invasive and Problem Plant Species
The Florida Exotic Pest Plan Council (FLEPPC) maintains a list of exotic plans that have been
documented to (1)have adverse effects on Florida's biodiversity and plant communities, (2) cause
habitat loss due to infestations, and (3) impact endangered species via habitat loss and alteration. To
date, 9 non-indigenous plant species have been detected within the Clam Bay NRPA which are listed
by FLEPPC as Category I exotics. FLEPPC defines Category I plants as those that alter native plant
communities by displacing native species, change community structures or ecological functions, or
hybridize with natives. Category II plants have increase in abundance or frequency but have not yet
altered Florida plant communities to the extent shown by Category I species. These definitions do not
rely on the economic severity or geographic range of the problem,but rather on the documented
ecological damage caused by these plants (FLEPPC 2013).
FLEPPC Category I plants observed within the Clam Bay NRPA boundary:
- Brazilian Pepper(Schinus terrebinthifolius)
- Melaleuca(Melaleuca quinquenervia)
- Australian Pine (Casuarina equisetifolia)
- Beach Naupaka(Scaevola taccada)
- Earleaf Acacia(Acacia auriculiformis)
- Shoebutton Ardisia (Ardisia elliptica)
- Air Potato (Dioscorea bulbifera)
- Lantana(Lantana camara)
- Old World Climbing Fern (Lygodium microphyllum)
FLEPPC Category II plants observed within the Clam Bay NRPA boundary:
- Coconut Palm (Cocos nucifera)
- Wedelia(Sphagneticola trilobata)
- Oyster Plant(Tradescantia spathacea)
Mahoe (Talipariti tiliaceum)
Methodology outlining the management activities that will be used to treat exotics is found in Chapter
5 of this Management Plan.
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Listed Species
Smalltooth Sawfish (Pristis pectinata)
A juvenile smalltooth sawfish was observed in 2008 in the connector creek between Inner and Outer
Clam Bays. Smalltooth sawfish are found in the tropical and subtropical Atlantic Ocean. In the
western Atlantic they have historically ranged from New York to Brazil, including the Gulf of Mexico
and Caribbean Sea. Habitat destruction and overfishing have succeeded in eradicating the smalltooth
sawfish from the majority of its former range. Consequently, it survives in small pockets throughout its
current range. The last remaining population in U.S. waters is off south Florida, a small remnant of a
population that once ranged from New York to Texas.
This sawfish primarily occurs in estuarine and coastal habitats such as bays, lagoons, and rivers. It
does at times occur in deeper waters, however, and may make crossings to offshore islands. It can
tolerate freshwater. This fish is easily recognized by its flattened body and wing-like pectoral fins. The
mouth is located ventrally, the eyes are positioned dorsally. The "saw" is approximately 25% of the
body's total length. It is widest at the base, with teeth more broad than long, and spaced apart. The tips
of the teeth are sharp, becoming blunt over time. Dorsally, it is brownish or bluish gray body with a
white underside. The maximum length recorded is 24.7 feet (7.6 m); however, a length of 18 feet (5.5
m) is considered average. The average lifespan for the smalltooth sawfish is unknown.
On April 1, 2003 the U.S. National Marine Fisheries Service placed the smalltooth sawfish on the
Endangered Species List, making it the first marine fish species to receive protection under the
Endangered Species Act. Florida has also designated critical habitat areas to further protect its habitat.
Mangrove Rivulus (Rivulus marmoratus)
This small fish has not been identified within the Clam Bay system in previous surveys or field work
but the mangrove habitat is appropriate and they could be present in the upper reaches of the mangrove
forest. The mangrove rivulus is primarily a saltwater or brackish water species, with limited
occurrence in freshwater. Within the Everglades and along Florida's west coast, this fish occurs in
stagnant, seasonal ponds and sloughs as well as in mosquito ditches within mangrove habitats. The
mangrove rivulus is able to survive in moist detritus without water for up to 60 days during periods of
drought, anaerobic, or high sulfide conditions.
This fish can reach a maximum size of 2 inches (5 cm) in length, however it is more commonly
observed at lengths between 0.4-1.5 inches (1.0-3.8 cm). The head and body are maroon to dark
brown or tan, with small dark spots and speckling on the body, particularly the sides. The dorsal
surface is always darker than the creamy ventral surface. The color of the body is reflective of the
habitat, with light coloration in areas of light colored sediments and darker coloration in environments
with dark leaf litter substrates. A large dark spot surrounded by a band of yellow is located at the upper
base of the caudal fin in hermaphroditic individuals. Males lack this dark spot and have a red-orange
cast to their flanks and fins.
The mangrove rivulus was once listed as a threatened species in the Gulf of Mexico. However, recently
additional surveys have revealed the existence of numerous populations. In Florida it has been
downlisted to a species of special concern. In 1999, it was submitted by the National Marine Fisheries
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Service as a candidate for protection under the Endangered Species Act. As of yet, it has not been
officially listed as endangered or threatened.
The main threat to the survival of the mangrove rivulus is habitat degradation and destruction as well
as exposure to pollutants. Disturbances that alter salinity and temperature as well as vegetation cover
may also reduce naturally occurring populations.
Loggerhead Sea Turtle (Caretta caretta)
Loggerhead sea turtles have been documented nesting on beaches within the Clam Bay NRPA.
Loggerheads are circumglobal, occurring throughout the temperate and tropical regions of the Atlantic,
Pacific, and Indian Oceans. They are the most abundant species of sea turtle found in U.S. coastal
waters. In the Atlantic, the loggerhead turtle's range extends from Newfoundland to as far south as
Argentina.
During the summer, nesting occurs primarily in the subtropics. Although the major nesting
concentrations in the U.S. are found from North Carolina through southwest Florida, minimal nesting
occurs outside of this range westward to Texas and northward to Virginia. Adult loggerheads are
known to make extensive migrations between foraging areas and nesting beaches. During non-nesting
years, adult females from U.S. beaches are distributed in waters off the eastern U.S. and throughout the
Gulf of Mexico, Bahamas, Greater Antilles, and Yucatan.
Loggerheads were named for their relatively large heads, which support powerful jaws and enable
them to feed on hard-shelled prey, such as whelks and conch. The top shell (carapace) is slightly heart-
shaped and reddish-brown in adults and sub-adults, while the bottom shell (plastron) is generally a pale
yellowish color. The neck and flippers are usually dull brown to reddish brown on top and medium to
pale yellow on the sides and bottom.
In the southeastern U.S., mating occurs in late March to early June and females lay eggs between late
April and early September. Females lay three to five nests, and sometimes more, during a single
nesting season. The eggs incubate approximately two months before hatching sometime between late
June and mid-November.
Loggerheads occupy three different ecosystems during their lives: beaches (terrestrial zone), water
(oceanic zone), and nearshore coastal areas ("neritic" zone). Because of this,NOAA Fisheries and the
U.S. Fish and Wildlife Service (USFWS) have joint jurisdiction for marine turtles, with NOAA having
the lead in the marine environment and USFWS having the lead on the nesting beaches.
The loggerhead turtle was first listed under the Endangered Species Act as threatened throughout its
range on July 28, 1978. In September 2011,NMFS and U.S. Fish and Wildlife Service listed 9 Distinct
Population Segments of loggerhead sea turtles under the ESA. The population in our Northeast
Atlantic Ocean Segment is listed as endangered. The agencies are currently proposing Critical Habitat
designations on several areas which contain a combination of nearshore reproductive habitat, winter
area, breeding areas, and migratory corridors. The Clam Bay NRPA is contained within the LOGG-N-
27 segment of this proposed critical habitat area.
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Gopher Tortoise (Gopherus polyphemus)
Gopher tortoises and their burrows are found along the coastal strand portions of the Clam Bay NRPA.
The range of the tortoise includes southern portions or Alabama, South Carolina, Louisiana,
Mississippi, and Georgia as well as most of Florida.
Gopher tortoises are one of the few species of tortoise that dig burrows. These burrows can be up to ten
feet deep and 40 feet long, and are as wide as the length of the tortoise that made it. In addition to
providing the tortoise a home, it has been documented that as many as 350 other species also use the
burrows including the indigo snake, Florida mouse, gopher frog and burrowing owl.
Gopher tortoises can live 40 to 60 years in the wild and average 9 to 11 inches in length. These
tortoises are superb earth-movers, living in long burrows from 5 to 45 feet long and up to 10 feet deep
that offer refuge from cold, heat, drought, forest fires and predators. The burrows maintain a fairly
constant temperature and humidity throughout the year and protect the gopher tortoise and other
species from temperature extremes, drying out, and predators. The mating season generally runs from
April through June and gestation for the eggs is between 80 and 100 days.
The shell or "carapace" of the gopher tortoise is mostly brownish gray and the underside of the shell, or
"plastron," is yellowish tan. Their front legs are shovel-like which helps them when digging their
burrows.
The gopher tortoise has been regulated in Florida since 1972 and has been fully protected since 1988.
Despite the afforded protection, gopher tortoise populations throughout the state have declined. As a
response to the continuing decline of the species, a new management plan was drafted and approved in
September 2007 as a precursor to reclassifying the gopher tortoise from a "species of special concern"
to a "threatened species." The threatened status was approved and went into effect on November 8,
2007.
Piping Plover (Charadrius melodus)
Piping plovers have been rarely sighted foraging or resting along the shoreline within the Clam Bay
NRPA boundaries. No nesting activities have been documented within the NRPA.
Piping plovers are small shorebirds approximately seven inches long with about a 19 inch wingspan.
They have sandy/grey colored plumage on their backs and crown and white underparts. Breeding birds
develop a single black breast band, a black bar across the forehead, bright orange legs and bill with a
black tip on the bill. During the winter, the birds lose the black bands, the legs fade to pale yellow, and
the bill becomes mostly black.
Piping plovers breed in three geographic regions of North America: the Atlantic Coast(which is where
the Clam Bay NRPA is located), the Northern Great Plains, and the Great Lakes. Nesting in the
Atlantic Coast region occurs on coastal beaches, sand flats and bars associated with barrier islands,
gently sloped and sparsely vegetated dunes, and washover areas cut into or between dunes. Plovers
from all three breeding populations winter along South Atlantic, Gulf Coast, and Caribbean beaches
and barrier islands, primarily on intertidal beaches with sand and/or mud flats with no or very sparse
vegetation.
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Piping plover populations were federally listed as threatened and endangered in 1986. The Northern
Great Plains and Atlantic Coast populations are threatened, and the Great Lakes population is
endangered. Piping plovers are considered threatened throughout their wintering range. The highest
concentration of birds reported in winter censuses are found in Texas, Louisiana, and Florida. In recent
decades, piping plover populations have drastically declined as breeding habitat has been replaced with
shoreline development and recreation. (USFWS).
West Indian Manatee (Rivulus marmoratus)
Manatees have been sighted on numerous occasions within the Clam Bay NRPA boundaries. Manatees
can be found in shallow, slow-moving rivers, estuaries, saltwater bays, canals, and coastal areas
particularly where seagrass beds or freshwater vegetation flourish. Manatees are a migratory species.
Within the United States, they are concentrated in Florida in the winter. In summer months, they can
be found as far west as Texas and as far north as Massachusetts, but summer sightings in Alabama,
Georgia and South Carolina are more common.
Manatees are large, gray aquatic mammals with bodies that taper to a flat, paddle-shaped tail. They
have two forelimbs, called flippers, with three to four nails on each flipper. The average adult manatee
is about 10 feet long and weighs between 800 and 1,200 pounds. They eat a large variety of
submerged, emergent, and floating plants and can consume 10-15% of their body weight in vegetation
daily. Because they are mammals, they must surface to breathe air. They rest just below the surface of
the water, coming up to breathe on an average of every three to five minutes. It is believed that one
calf is born every two to five years, and twins are rare. The gestation period is about a year. Mothers
nurse their young for one to two years, during which time a calf remains dependent on its mother.
Protections for Florida manatees were first enacted in 1893. Today, they are protected by the Florida
Manatee Sanctuary Act and are federally protected by both the Marine Mammal Protection Act and the
Endangered Species Act
Other Species
Plant Species-List based on FLUCFCS Mapping
FLUCFCS Code 181 —Swimming Beach
COMMON NAME SCIENTIFIC NAME
Seagrape Coccoloba uvifera
Sea Oats Uniola paniculata
Railroad vine Ipomoea pes-caprae
FLUCFCS Code 322—Coastal Scrub
COMMON NAME SCIENTIFIC NAME
Seagrape Coccoloba uvifera
Cabbage Palm Sabal palmetto
Buttonwood Conocarpus erectus
Spanish Bayonet Yucca aloifolia
Saltbush Baccharis halimifolia
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Beach Naupaka Scaevola taccada
FLUCFCS Code 428— Cabbage Palm Hammock
COMMON NAME SCIENTIFIC NAME
Cabbage Palm Sabal palmetto
Seagrape Coccoloba uvifera
Strangler Fig Ficus aurea
Saffron Plum Sideroxylon celastrinum
Coinvine Dalbergia ecastaphyllum
Brazilian Pepper Schinus terebinthifolius
Beach Naupaka Scaevola taccada
FLUCFCS Code 612—Mangrove Swamps (Forest)
COMMON NAME SCIENTIFIC NAME
Red Mangrove Rhizophora mangle
White Mangrove Laguncularia racemosa
Black Mangrove Avicennia germinans
Buttonwood Conocarpus erectus
Leather Fern Acrostichum danaeifolium
Saltwort Batis maritima
FLUCFCS Code 642—Salt Marsh
COMMON NAME SCIENTIFIC NAME
Lance-leaf Arrowhead Sagittaria lancifolia
Needlerush Juncus roemerianus
Bulrush Scirpus californicus
Carolina Willow Salix caroliniana
Peruvian Primrosewillow Ludwigia peruviana
Animal Species
The following lists of species have been observed within the Clam Bay NRPA and the adjacent Pelican
Bay development areas. These lists are not all inclusive but represent a wide array of the species found
within and adjacent to the Clam Bay NRPA habitats.
Fish
COMMON NAME SCIENTIFIC NAME
Atlantic needlefish Strongylura marina
Barracuda Sphyraena barracuda
Bay anchovy Anchoa mitchilli
Blacktip Shark Carcharhinus limbatus
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Blue crab Callinectis sapidus
Cowfish Acanthostracion quadricomis
Flounder Paratichthys alblgutta
Gray snapper Lutjanus griseus
Great barracuda Sphyraena barracuda
Gulf killifish Fundulus grandis
Inshore Iizardfish Synodusfoetens
Killifish spp. Fundulus spp.
Leatherjacket Oligoplites saurus
Longnose killifish Fundulus simitis
Mangrove snapper Lutjanus griseus
Mullet Mugil cephalus
Mutton snapper Lutjanus anatis
Needlefish Strongylura marina
Permit Trachinotus falcatus
Pigfish Orthopristus chrysoptera
Pinfish Lagodon rhomboides
Pipefish Syngnathus spp.
Puffer Sphoeroides parvus
Sailfin molly Poecilia latipinna
Sand perch Diplectrum bivittatum
Scaled sardine Harengula pensacolae
Sea robin Prionotus scitulus
Sheepshead Archosargus probatocephal
Sheepshead minnow Cyprinodon variegatus
Silver jenny Eucinostomus gula
Smalltooth Sawfish Pristis pectinata
Snook Centropomus undecimalis
Spot Leiostomus xanthurus
Spotfin mojara Eucinostomus argenteus
Spotted seatrout Cynoscion nebulosus
Tidewater silverside Menidia peninsulae
Triggerfish Batistes capriscus
White grunt Haemulon plumierii
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Whiting Menticirrhus tittoratis
Reptiles and Amphibians
COMMON NAME SCIENTIFIC NAME
SNAKES
Banded water snake Nerodia faciata faciata
Black racer Coluber constrictor
Common garter snake Thamnophis sirtalis
Eastern coachwhip Masticophis flagellum
Mangrove salt marsh water snake Nerodia clarkii
Mud snake Farancia abacura
Red rat snake Elaphe guttata guttata
Ring-necked snake Diadophis punctatus
Yellow rat snake Elaphe obsoleta
LIZARDS AND CROCODILIANS
American alligator Alligator mississippiensis
Brown anole Anolis sagrei
Brown basilisk lizard** Basiliscus vittatus
Cuban knight anole** Anolis equestris
Eastern glass lizard Ophisaurus ventralis
Green anole Anolis carolinensis
Southeastern five-lined skink Eumeces inexpectatus
FROGS AND TOADS
Cuban treefrog Osteopilus septentrionalis
Eastern narrow-mouthed toad Gastrophryne carolinensis
Eastern spadefoot toad Scaphiopus holbrookii
Giant marine toad** Rhinella marina (fka Bufo marinus)
Green treefrog Hyla cinerea
Oak toad Anaxyrus quercicus
Southern leopard frog Lithobates sphenocephalus
Southern toad Bufo terrestris
Squirrel treefrog Hyla squirella
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TURTLES AND TORTOISES
Chicken turtle Deirochelys reticularia
Florida box turtle Terrapene carolina bauri
Florida redbelly cooter Pseudemys nelsoni
Florida snapping turtle Chelydra serpentina osceola
Florida softshell turtle Apalone ferox
Gopher tortoise Gopherus polyphemus
Green sea turtle Chelonia mydas
Loggerhead sea turtle Caretta caretta
Penninsula cooter Pseudemys peninsularis
Pond(yellowbelly) slider Trachemys scripta scripta
Striped mud turtle Kinosternon baurii
Birds
COMMON NAME SCIENTIFIC NAME
American avocet Recurvirostra americana
American coot Fulica americana
American kestrel Falco sparverius
American oystercatcher Haematopus palliatus
American Robin Turdus migratorius
Anhinga Anhinga anhinga
Bald eagle Haliaeetus leucocephalus
Barred owl Strix varia
Belted kingfisher Megaceryle alcyon
Black skimmer Rynchops niger
Black vulture Rynchops niger
Black-and-white warbler Mniotilta varia
Black-bellied plover Pluvialis squatarola
Black-crowned night heron Nycticorax nycticorax
Black-necked stilt Himantopus mexicanus
Blue jay Cyanocitta cristata
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Blue-gray gnatcatcher Polioptila caerulea
Boat-tailed grackle Quiscalus major
Brown pelican Pelecanus occidentalis
Brown thrasher Toxostoma rufum
Budgerigar Melopsittacus undulatus
Caspian tern Hydroprogne caspia
Cattle egret Bubulcus ibis
Chuck-will's-widow Caprimulgus carolinensis
Common grackle Quiscalus quiscula
Common ground-dove Columbina passerina
Common moorhen Gallinula chloropus
Common nighthawk Chordeiles minor
Common snipe Gallinago gallinago
Common tern Sterna hirundo
Common yellowthroat Geothlypis trichas
Double-crested cormorant Phalacrocorax auritus
Dowitcher long-billed Limnodromus scolopaceus
Dowitcher short-billed Limnodromus griseus
Downy woodpecker Picoides pubescens
Dunlin Calidris alpina
Eastern screech owl Megascops asio
Eurasian collared dove Streptopelia decaocto
European starling Sturnus vulgaris
Fish crow Corvus ossifragus
Forster's tern Sterna forsteri
Glossy ibis Plegadis falcinellus
Gray catbird Dumetella carolinensis
Great blue heron Ardea herodias
Great crested flycatcher Myiarchus crinitus
Great egret Ardea alba
Great horned owl Bubo virginianus
Greater yellowlegs Tringa melanoleuca
Green heron Butorides virescens
Green-winged teal Anas crecca
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Herring gull Larus argentatus
Hooded merganser Lophodytes cucullatus
House sparrow Passer domesticus
Killdeer Charadrius vociferus
Laughing gull Leucophaeus atricilla
Least sandpiper Calidris minutilla
Limpkin Aramus guarauna
Little blue heron Egretta caerulea
Loggerhead shrike Lanius ludovicianus
Magnificent frigate bird Fregata magnificens
Mangrove cuckoo Coccyzus minor
Merlin Falco columbarius
Mocking bird Mimus polyglottos
Mottled duck Anas fulvigula
Mourning dove Zenaida macroura
Muscovy duck Cairina moschata
Northern cardinal Cardinalis cardinalis
Northern gannet Morus bassanus
Northern parula Parula americana
Northern waterthrush Seiurus noveboracensis
Osprey Pandion haliaetus
Painted bunting Passerina ciris
Palm warbler Dendroica palmarum
Peregrine falcon Falco peregrinus
Pied-billed grebe Podilymbus podiceps
Pilleated woodpecker Dryocopus pileatus
Piping plover Charadrius melodus
Prairie warbler Dendroica discolor
Purple gallinule Porphyrula martinica
Red knot Calidris canutus
Red-bellied woodpecker Melanerpes carolinus
Red-breasted merganser Mergus serrator
Reddish egret Egretta rifescens
Red-shouldered hawk Buteo lineatus
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Red-tailed hawk Buteo jamaicensis
Red-winged blackbird Agelaius phoeniceus
Ring-billed gull Larus delawarensis
Roseate spoonbill Platalea ajaja
Royal tern Sterna maxima
Ruby-throated hummingbird Archilochus colubris
Ruddy turnstone Arenaria interpres
Sanderling Calidris alba
Sandwich tern Sterna sandvicensis
Semipalmated plover Charadrius semipalmatus
Snowy egret Egretta thula
Spotted sandpiper Actitis macularia
Swallow-tailed kite Elanoides forficatus
Tri-colored heron Egretta tricolor
Turkey vulture Cathartes aura
Western sandpiper Calidris mauri
White ibis Eudocimus albus
White pelican Pelecanus erythrorhynchos
Willet Catoptrophorus semipalmatus
Wood stork Scolopax minor
Yellow-bellied sapsucker Sphyrapicus varius
Yellow-crowned night heron Nyctanassa violacea
Yellow-rumped warbler Dendroica coronata
Yellow-throated warbler Dendroica dominica
Mammals
COMMON NAME SCIENTIFIC NAME
Big brown bat Eptesicus fuscus
Bobcat Lynx rufius
Bottle-nosed dolphin Turciops truncatus
Brazilian free-tailed bat Tadarida braziliensis
Coyote Canis latrans
Eastern gray squirrel Sciurus carolinensis
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Eastern mole Scalopus aquaticus
Feral domestic cat Felis catus
Florida Black bear Ursus americanus floridanus
Florida Panther Puma concolor coryi
Gray fox Urocyon cinereoargenteus
House mouse Mus musculus
Marsh rabbit Sylvilagus palustris
Nine-banded armadillo Dasypus novemcinctus
Raccoon Procyon lotor
River otter Lutra canadensis
Roof rat Rattus rattus
Virginia opossum Didelphis Virginia
West Indian manatee Trichechus manatus
Hydrology
Hydrological regime, sometimes referred to as the surface water or surficial hydrology, in simple terms
describes the long term spatial variation in the water depths and period of inundation within a wetland
system. This is because the surficial hydrology has both horizontal and vertical components and
provides key ecological functions to the mangrove forest. (Lewis,pers. comm. 2008)
With respect to the horizontal component, incoming water (both tidal and surface water run-off) into
an estuary brings with it nutrients, dissolved oxygen, and marginally lower salt concentrations.
Conversely, the outgoing water leaving a mangrove wetland (through tidal exchange) removes
metabolic waste products (e.g., carbon dioxide and toxic sulfides) and excess salt. The vertical
component refers to incoming water that percolates down into the sediment and root zone, and the
sediment drainage, on a falling tide,which removes metabolic wastes and excess salt.
It is the inflow and outflow of sea water that is critical to the ability of the estuary to manage these two
ecological functions and as such dissipate salts, organic matter and freshwater. It follows that anything
that affects the system and alters the ability of the system to perform these functions, will, in most
instances, cause stress to the system and, at some point in time, result in the death of the system, or
portions of it.
Hydrologic studies indicate that the tidal flushing capacity of Clam Bay prior to the restoration
dredging was limited and almost insignificant in Upper Clam Bay. The preliminary hydrographic
assessment of the Clam Bay system prepared by Tackney & Associates, Inc. (August 1996)
demonstrated rather dramatically that there was a significant reduction in tidal range between the
middle boardwalk and Inner Clam Bay. Tackney described the flow in that area as "measurably
reduced" and "very inefficient". This connecting tidal creek is the key conduit for tidal input and
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outflow to the northern reaches of the Clam Bay system. And its constriction and the ancillary
constriction of tributaries connection to it, impact the quantity and quality of the flushing that can
occur in Inner and Upper Clam Bay.
Another key aspect of the surficial hydrology is the vertical location of the water level elevation
relative to the sediment elevation. Specifically, the mean low water (tide) elevation has to be
sufficiently lower than the sediment elevation in order for sediments to drain during low tide. A
persistent high surface water elevation stops sediment drainage and results in anoxic sediment and the
accumulation of toxic waste products. The absence of meaningful exchange was certainly a
contributor to the significant degradation of the mangrove system within Clam Bay. (Tackney 1996;
Lewis pers. comm. 2008).
In this context Tackney observed that even in the absence of rainfall, the average water surface
elevations for the inner and upper bays were higher than the average surface elevation for the Gulf.
Analysis of the tidal data indicated that average water surface elevations in the Inner and Upper Clam
Bays were both elevated above the average Gulf water surface elevation by approximately 0.2 feet.
This indicated that the tidal range in Inner and Upper Clam Bays was muted and that the system was
receiving significant additional water through runoff and restricted capacity to drain additional inflow.
In fact, during portions of the Tackney study no tidal fluctuation was noted in the Upper Clam Bay and
only marginal tidal effects were observed in Inner Clam Bay.
The reduced tidal ranges were also accompanied by relatively large phase lags. The phase lag is the
average time delay measured in hours and minutes between the occurrence of slack(high or low)water
in the Gulf of Mexico and the measurement stations. It is affected by both the distance between
measurement stations and the amount and quality of hydraulic resistance of the connecting channel.
The longer the distance and the higher the resistance,the more pronounced one would expect the phase
lag to be. In the upper bays, high and low waters generally occurred over three hours later than the
Gulf tides.
These conditions indicate that the tidal creeks connecting the interior bays are hydraulically very
inefficient. As a result, the upper bays are prone towards extended periods of flooding as a result of
freshwater runoff and the inability of the system to drain efficiently. During Tackney's field studies of
May 1996, rainfall of approximately 4 inches in three days was adequate to flood the Upper Clam Bay
above high tide levels and sustain this flooded condition for over two days. Accordingly, he concluded
that the creeks and bays that serve to connect the Inner and Upper Bays were significantly less efficient
in the ebb tide stage than they were in the flood stage. Studies undertaken by both Lewis
Environmental Services, Inc. and Turrell & Associates, Inc. would support this conclusion. (Turrell
1995).
Finally, an additional attribute of the system that is directly related to tidal prism and the quantity of
inflow and outflow is the question of inlet stability. Inlet stability refers to a tidal inlet's capacity to
adequately scour out deposited sediments and prevent inlet closure. For a given wave environment,
inlet stability is governed primarily by the volume of water (tidal prism) carried by the inlet. To
remain stable, an inlet must have the characteristic that a temporary constriction in cross sectional area
produces an increase in current velocities adequate to scour out the constriction. To function without
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mechanical intervention, the system must generate a sufficient volume of water on the ebb tide to scour
out the inlet naturally, otherwise the inlet will, over time, continue to close. This is particularly true
during periods of high wave activity and low tidal ranges. (Turrell 1995; Tackney 1996). The six
closures of Clam Pass that have occurred in the past twenty-five years indicate that stability of Clam
Pass is marginal. (Turrell 1995; Tackney 1996, Humiston 2010).
Freshwater Component
Under predevelopment conditions, much of the area's rainfall was held on the surface of the land in
sloughs and other low areas. This water would either slowly filter through the soil to recharge the
shallow aquifer or move through the mangrove community to the bay. Less than ten inches of the
approximately 53 inch average rainfall is estimated to have been lost from the uplands east of Clam
Bay as surface runoff. The storage capabilities of the land thus moderated surface flows, preventing
extremely high flow rates during the rainy season and serving to maintain surface flow and
groundwater flow during the dry season. (FDER 1981).
The development of Pelican Bay had limited fill impact to the Clam Bay system, but it did modify the
pattern of freshwater entering the Clam Bay system. (Wilson, Miller et.al. 1996). The stormwater
management system as designed, permitted and implemented at Pelican Bay employs a series of
detention ponds, swales and culverts to regulate the discharge of run-off into Clam Bay. Discharge
occurs almost continuously along the eastern perimeter of the conservation area. Run-off from the
northern end of Pelican Bay is collected and discharged into Upper Clam Bay. Irrigation water for 27
holes of golf and landscaping in Pelican Bay is approximately 3.0 MGD which approximates 26 inches
per year of additional rainfall equivalent, (Wilson, Miller et.al., 1996). When added to the average
rainfall for South Florida of approximately 53 inches per year,the local area has an effective rainfall of
approximately 80 inches plus annually. This is significant, particularly when viewed in the context of
predictable storm events that have the potential for altering the amount of average rainfall entering the
Clam Bay system.
The "Pelican Bay Water Management System — Stormwater Detention Volume and Water Budget
Analysis" (Wilson, Miller, Barton & Peek, Inc. April, 1996) describes the water management system
as being divided into six watersheds or drainage systems. Rainfall, including irrigation, reaches the
ground and either seeps into the ground or runs off to a stormwater detention area within each system.
The stormwater detention plan for Pelican Bay has a standard, permitted design capacity to hold the
first inch of stormwater during a 25-year storm event. The stormwater is detained for flood protection
and water quality treatment. Stormwater discharge is controlled by a series of weirs designed such that
the post-development stormwater run-off rate does not exceed pre-development rates. Stated
differently, the system is designed to discharge stormwater in the development portion of Pelican Bay
in the same manner that it discharged stormwater prior to development. The stormwater discharge
exits the weir system for a final release into Clam Bay.
Stormwater runoff from an additional 130 acres of watersheds, outside of Pelican Bay, contributes an
additional and significant volume of discharge to Clam Bay. This water represents 7.9% of the total
stormwater discharge to Clam Bay.
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fi �' r1u 'a�Y*arc)l'. i
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Approximate locations of Drainage Basins within the Pelican Bay Development(photo is oriented with north up and west
to the left).
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As the area of Pelican Bay to the east has undergone development, it has increased the impervious
surface area, with a concomitant increase in surface runoff, which is eventually discharged to Clam
Bay. The daily irrigation water volume enhances the saturation of the uplands which reduces their
ability to accommodate rainfall volume,thus effectively increasing surface and groundwater discharge.
Groundwater discharge can be commonly observed throughout-the eastern side of Clam Bay and is
discernable as a very slight sheet flow. Where this water encounters a discharge system, even one that
is not operating at peak efficiency (from an engineering,not historical, standpoint), such as Outer Clam
Bay, excess water is effectively removed from the system. However, in the northern section, sheet
flow was not efficiently removed due to lack of flow through the forest. Thus, it accumulated,
increasing soil saturation and raising the mean water table elevation, and apparently overwhelming the
black mangrove's anaerobic soil/gas exchange mechanisms. Mangroves in these areas became
stressed and died.
Water Quality
During the initial environmental permitting of Pelican Bay, the agencies required water quality testing
within the Pelican Bay subdivision and the Clam Bay estuary to help evaluate the impact of
development on Clam Bay. The water quality-testing program was first implemented by Pelican Bay
Improvement District (PBID) starting in the early 1980's. In 1990 PBID became the Pelican Bay
Services Division (PBSD), a dependent Division of Collier County. PBSD continued the testing
program after 1990. PBSD is currently the responsible entity for the testing program.
The water quality testing is performed at several sample points within Pelican Bay and Clam Bay. The
sample point locations are shown on the exhibit below. There are currently nine sampling locations
within Pelican Bay and Clam Bay. Sample points W-7 (located in the creek near the north Foundation
boardwalk), W-6 (located in the creek near the south Foundation boardwalk), W-1 (located near the
kayak launch area at the southern end of Outer Clam Bay),North Seagate (located on the north side of
the Seagate Culverts between Venetian Bay and Outer Clam Bay), and Upper Clam Bay (located at the
very north end of Upper Clam Bay) are within Clam Bay, which are categorized as Class II waters by
the Florida Department of Environmental Protection (FDEP). The remaining five sampling points are
PB-13 (located north of the Sandpiper parking lot on both sides of the berm), PB-11 (located between
the St. Maarten condominium and the Commons on the east side of the berm), Glenview (located
between the Glenview and Stratford condominiums on the east side of the berm), and St. Lucia
(located adjacent to the St. Lucia condominium on the east side of the berm), are located in the
stormwater treatment portion of the property (Class III waters)within Pelican Bay.
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CLAM BAY NRPA MANAGEMENTPelicanBayServices AN Di(DRAFVer.visiT)
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4on
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Sampling Locations
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Water quality sampling is conducted within the Clam Bay system on a monthly basis. The samples are
collected by PBSD staff and transported to the Collier County Pollution Control laboratory for
processing. Parameters sampled and collected, include;
• Field pH
• Field Temperature
• Field Salinity
• Field Dissolved Oxygen
• Ammonia
• Carbon- Total Organic
• Chlorophyll a
• Copper* (added to the parameter suite in 2013)
• Nitrate-Nitrite(N)
• Nitrite (N)
• Nitrogen-Total Kjeldahl
• Orthophosphate (0PO4)
• Pheophytin
• Phosphorus-Total
• Residues-Filterable (TDS)
• Silica(SiO2)
Water quality sampling results of nutrient loading seem to indicate that the development stormwater
management system is doing its job. No evidence of nutrient loading has been observed within the
Class II waters though several spikes and elevated nutrient(N and P) levels have been observed from
the testing locations along the berm. It is believed that the spikes observed are correlated with
fertilizer application within the community.
The Florida Department of Environmental Protection (FDEP)conducted water quality sampling within
the Clam Bay NRPA in 2001 and 2012. Based on their sample results, FDEP had made an initial
determination that Clam Bay could be impaired for both Dissolved Oxygen (DO) and Copper.
Subsequent coordination between FDEP, PB SD,the Pelican Bay Foundation, and involved
consultants, FDEP made a determination that the oxygen levels in Clam Bay were natural and the
system was not listed as impaired for DO.
FDEP did determine that the system was impaired for copper and was placing the system on the
Everglades West Coast verified list for copper with a medium TMDL priority(5 to 10 years for TMDL
development). Subsequent copper testing undertaken by PBSD has also shown periodic elevated
levels of copper within the Clam Bay Class II waters.
FDEP acknowledged that the Pelican Bay community is developing on an upland stormwater and
nutrient management program that is designed to reduce nutrient and copper inputs into the stormwater
system. Once completed, this program can be given to FDEP for review and if satisfied with the
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anticipated reduction of copper resulting from the implementation of the plan,the system could be
removed from the impaired list. While the upland nutrient management plan is not part of this
Management Plan,PBSD will work closely with the Pelican Bay Foundation to coordinate and share
information and to integrate management decisions and activities into this Management Plan where
appropriate.
Archaeological Resources
The Florida Division of Historical Resources Master Site File lists three known archaeological sites
within the Clam Bay NRPA boundary. All three are located within the mangrove forest habitat. Two
of the sites (CR476 and CR547) are located north of the Pass and south of Inner Clam Bay. The third
site (CR576) is located south of the Pass and north of the Clam Pass Park boardwalk.
Site CR476 is identified as a prehistoric campsite and shell midden possibly supporting the use of
several cultures dating from 8500 B.C.to A.D. 1700.
Sites CR547 and CR576 are identified as shell middens which were in use between 1000 B.C. and
A.D. 1700.
All three of the sites are within the mangrove forest and outside of the footprint of any previous or
future anticipated dredging activities.
Inlet Dynamics—To be added from Engineer's report(s)
Recreational Use
The Clam Bay NRPA provides a variety of opportunities for recreation such as walking, kayaking,
canoeing,paddle boarding, swimming, fishing, and snorkeling. Many Collier County residents and
visitors enjoy the natural environment of the preserve. Recent stakeholder input as well as prior
reports supports the use of the Clam Bay NRPA for recreational endeavors. It is important that all who
participate in recreational activities within the system do no harm to the unique flora and fauna.
Clam Bay's dense forest of mangroves significantly limits walking in the preserve. Most walkers
seeking to enjoy the rich natural environment of Clam Bay use the three boardwalks that cross the
preserve and provide access to the beach. Residents and guests of Pelican Bay residents use the
northern and middle boardwalks. The southern most boardwalk is open to the public and accessed
from the parking lot at the south end of the system. Trams are used on all three boardwalks to transport
those choosing not to walk on the boardwalk to the beach.
Kayaks, canoes and paddleboards are used by those wanting to enjoy the natural setting and serenity of
Clam Bay's waterways. There is a public launching area adjacent to the parking lot at the south end of
the bay, and there is also a private launch for Pelican Bay residents on the northern boardwalk. The
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canoe/kayak trail is clearly designated by canoe trail markers from Outer Clam Bay to Upper Clam
Bay.
Fishing and swimming are also popular pastimes. Fishing can be done from the boardwalks and canoes
or by wading into the water. Swimming is usually confined to the beach areas, but some swimmers and
waders, if conditions permit, venture into Clam Pass.
The use of motorized vessels is restricted by the ephemeral nature of Clam Pass and the shallow waters
of the bay system (Collier County Manatee Protection Plan, 1995). Under Florida Statute 327.46,the
speed of motorized vessels in portions of the Clam Bay NRPA can be restricted to either idle speed/no
wake or slow speed/minimum wake through the enactment of Collier County ordinances and
subsequent approval by the Florida Fish and Wildlife Conservation Commission. In the future should
any adverse effects on Clam Bay's natural resources or water quality be found to be related to
motorized watercraft, additional management options will be explored to ameliorate these adverse
effects.
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4.0 Authorized Construction Activities
List of permits for work undertaken to date and relevant legal framework
Eighteen years ago, Collier County processed a permit to dredge limited areas of Clam Pass to
facilitate the movement of tidal water in and out of Clam Bay. The FDEP permit for this activity was
issued on March 28, 1996 with the companion USACOE permit being issued on April 2, 1996. The
FDEP permit was modified on April 10, 1996 with the authorized work being undertaken and
completed on April 17, 1996. The practical effect of implementing this Permit was to reopen the Pass,
but it was clear that without a more comprehensive strategy, this effort, standing alone, would not
revitalize the Clam Bay ecosystem.
A permit to improve the channel flow within defined areas of the Clam Bay system by a combination
of blasting and hand excavation was issued on June 26, 1996. The work was undertaken and
completed in two segments. The first channels were opened in August 1996 and the second channels
were opened in November 1996. The results of these two initiatives were positive in that measurable
improvements in tidal flow were discernible and with that have come improved conditions for natural
re-vegetation.
A permit was issued on January 5, 1997 to construct a portable pump and pipe system as an interim
measure to divert freshwater within the Clam Bay system to the Gulf while a more permanent solution
contemplated by the construction of an outfall structure was reviewed. Although this plan was never
implemented and is no longer considered, it envisioned two pumps that would be operational when the
water surface elevation within Clam Bay exceeded a specified threshold. The Management Plan
anticipated the direct discharge of excess water into the Gulf with the expectation that this system
would augment the natural discharge through the tidal mechanism after severe storm events.
Subsequently, Collier County authorized the pursuit of a ten-year permit to allow the County, or its
designee (which in this case was the Pelican Bay Services Division), to maintain Clam Pass in an open
condition. The application, as filed, did not address any other issues affecting the operational
characteristics of Clam Bay and essentially mirrored the 1996 Permit described in the first paragraph
above. Agency comments and concerns which arose as part of the permit review led to the creation of
the 1998 Clam Bay Restoration and Management Plan. The CBRMP addressed agency concerns at the
time and included provisions for adding one-way flap gates to the Seagate culverts, dredging within
three sections of the creek north of Clam Pass, a network of hand dug channels throughout the forest
area, in addition to the dredging of the Pass. This permit was issued in 1998 and the Management Plan
created in support of the permit has been the guiding document for the maintenance activities
undertaken in the Clam Bay system since then.
It is anticipated that FDEP and USACE 10-year permits will be sought in conjunction with this new
Management Plan. The permits will allow for ongoing maintenance activities to continue along with
occasional, modest removal of material by dredging within a discreet area of Clam Pass in order to
maintain the existing tidal regime within the system. Any changes to the submitted dredging scope or
other new management initiatives will be reviewed by the PBSD Board and Collier County
Commissioners before seeking any additional permit(s) which may be necessary for the modified
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activities. Additional investigations which may be undertaken at a later date to look at, for example,
faunal investigations, more in-depth water quality concerns, or other issues that may arise as a result of
stakeholder discussions could also necessitate permitting which will have to be reviewed by the PBSD
and BCC prior to any such permit applications being submitted. This Management Plan is specifically
tasked to maintain the improvements and benefits already realized and to insure that the restoration
success observed to date is continued. Dredging for navigation or beach renourishment will not be
done.
The following list contains more details related to existing and historical permits issued for the Clam
Bay system.
Permit Details
South Florida Water Management District Surface Water Permit No.: 11-00065-S
Date of Issue: August 10, 1978
Expiration Date: Operational phase doesn't expire
Project Description: To construct and operate water management systems 1 and 2 serving 539 acres of
residential lands discharging by westerly sheet flow to Inner, Outer,and Upper Clam Bays.
Department of Environmental Regulation Construction Permit/Certification No.: 11-50-3769
Date of Issue: May 23, 1979
Expiration Date: May 15, 1984
Project Description: To provide construction sites for residential development in a planned community
by: placing approximately 700,000 cy of clean upland fill material onto approximately 94 plus acres
of submerged lands of waters of the state landward of the line of mean high water.
Department of the Army Corps of Engineers Permit No.: 00754929
Date of Issue: November 18, 1981
Expiration Date: November 18, 1984
Project Description: This permitted the filling of 75+ acres of mangrove wetlands north, east and west
of Upper Clam Bay and south of Vanderbilt Beach Road.
Department of Environmental Regulation Modification Permit No.: 11-50-3769
Date of Issue: December 23, 1981
Expiration Date: November 18, 1986
Project Description: This modification extended the expiration date of the permit to November 18,
1986.
Department of the Army Corps of Engineers Permit No.: 79K-0282
Date of Issue: August 2, 1983
Expiration Date: November 18, 1986
Project Description: This was an extension of the permit authorizing the filling of 75+ acres of
mangrove wetlands north, east and west of Upper Clam Bay and south of Vanderbilt Beach Road, plus
approximately 2 acres of mangroves at the existing Collier County beach access at Vanderbilt Beach
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Road. The request was reviewed and no objections were raised to the proposed work schedule;
therefore,the completion date of the permit was extended for 2 years until November 18, 1986.
South Florida Water Management Plan Modification of Surface Water Management Permit No.: 11-
00065-5
Date of Issue: December 15, 1983
Date of Expiration: Operational phase doesn't expire
Project Description: Approved modifications to 1) Revise system V, drainage area 3. 2) Construction
and operation of water management system number VI.
Department of Environmental Regulation Permit/Certification No: 110974055
Date of Issue: September 12, 1985
Expiration Date: September 11, 1987
Project Description: To construct approximately 2900 linear feet of 10' wide public access elevated
boardwalk and pier with a 6' wide navigation access lift gate in Outer Clam Bay.
Department of the Army Corps of Engineers Permit No.: 86IPT-20328
Date of Issue: December 18, 1986
Expiration Date: December 18, 1991
Project Description: Discharge±2.3 acres of clean fill to construct an access road.
Department of Environmental Regulation Modification Permit No.: 11-50-3769
Date of Issue: January 7, 1987
Expiration Date: December 18, 1991
Project Description: This permit modification extended the expiration date and reduced the amount of
fill in the area extending south along the coastal edge from approximately 13 acres, as permitted, to
2.43 acres in order to construct a linear access road (for The Strand in Bay Colony).
Department of Environmental Protection Permit/Certification No: 112659015
Date of Issue: March 14, 1995
Expiration Date: March 14, 2000
Project Description: Re-establish the connection between the Gulf of Mexico to the Clam Bay system,
by dredging from the mouth of Clam Pass and spoiling the sand over an upland beach site.
Collier County Ordinance No: 96-16
Date of Issue: April 9, 1996
Expiration Date: n/a
Project Description: To impose idle speed/no wake zones in the Clam Bay system.
Department of Environmental Protection Permit/Authorization No.:0128463-001-JC
Date of Issue: July 06, 1998
Expiration Date: July 06, 2008
Project Description: This Permit authorized activities to improve the hydrodynamics of, and thus
restore and manage, the Clam Bay ecosystem.
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Department of the Army Corps of Engineers Permit No.:199602789 (IP-CC)
Date of Issue: August 11, 1998
Expiration Date: July 08, 2008
Project Description: This Permit authorized the following works: 1) Replacement of Seagate Drive
Culverts and installation of one-way check valves on the culverts (pages 45 — 50 of the CBRMP). 2)
Clam Pass main channel dredging for Cuts 1, 2, 3 and 4(pages 49—65 of the CBRMP). 3) Excavation
and maintenance of Interior Tidal Creeks (pages 65 —71 of the CBRMP).
Department of Environmental Protection Permit Modification DEP Permit No:0128463-001-JC
Date of Issue: December 15, 1998
Expiration Date: July 06, 2008
Project Description: This permit modification authorized: 1) an alternative to upland spoil disposal
area for Cut#1;2) an increase in the width of the channel Cut#4 through Clam Pass; and 3)alternative
pipeline corridors between the dredge cuts and the disposal areas.
Department of Environmental Protection Permit Modification for Permit No: 0128463-001-JC
Date of Issue: February 16, 1999
Expiration Date: July 6, 2008
Project Description: Authorize minor revisions to the mangrove trimming procedures pursuant to site
verification.
Department of the Army Corps of Engineers Modification for Permit No.:199602789 (IP-CC)
Date of Issue: February 26, 1999
Expiration Date: July 08, 2008
Project Description: This application requested a modification to: 1) discharge the dredge material
from Cut#1 to new disposal area identified as an upland parking area; 2) increase the width of channel
Cut #4; 3) remove native vegetation and excavate a portion of upland Disposal Site #2; 4) remove
native vegetation and excavate a portion of upland Disposal Site #3. Issues 1 & 2 were found to be
insignificant and the permit was modified. The requests regarding issues 3 & 4 were not approved at
this time.
Department of the Army Corps of Engineers Modification for Permit No.:199602789 (IP-CC)
Date of Issue: March 08, 1999
Expiration Date: July 08, 2008
Project Description: This application requested a modification to: 1) discharge the dredge material
from Cut#1 to new disposal area identified as an upland parking area; 2) increase the width of channel
Cut #4; 3) remove native vegetation and excavate a portion of upland Disposal Site #2; 4) remove
native vegetation and excavate a portion of upland Disposal Site #3. The proposed modification to
widen channel Cut #4 is to be done without any additional seagrass impacts. Based on the review and
coordination with FWS,the permit was modified in accordance with these requests.
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Department of Environmental Protection Permit Modification for Permit No: 0128463-001-JC
Date of Issue: May 19, 1999
Expiration Date: May 28, 1999
Project Description: Re-grade beach fill material during the marine turtle nesting season to remove
pockets of fine silty material and to remove an escarpment which may interfere with nesting marine
turtles.
Florida Fish and Wildlife Conservation Commission File No: 2003-0511-016BS for Permit No: CO-
016
Date of Issue: March 24, 2000
Expiration Date: n/a
Project Description: This Permit granted approval for placement of canoe trail markers in Clam Bay.
Department of the Army Corps of Engineers for Permit No: 200001076 (NW-EF)
Date of Issue: April 13, 2000
Expiration Date: February 11, 2002
Project Description: Approved the installation of 32 waterway markers for a canoe trail in the Clam
Bay system.
Department of the Army Corps of Engineers Modification for Permit No.:199602789 (IP-CC)
Date of Issue: May 05, 2000
Expiration Date: July 08, 2008
Project Description: This application requested modifications to the monitoring and reporting schedule
referenced on page 93 (Biological Monitoring) of DA Permit (CBRMP). The request was to submit
annual reports instead of semi-annual reports. The permit was modified as requested.
Department of Environmental Protection Permit for Permit No: CO-732
Date of Issue: October 25, 2002
Expiration Date: October 25, 2003
Project Description: Perform dune and beach restoration, and plant salt-tolerant native dune vegetation
in association with interim maintenance dredging event.
Department of the Army Corps of Engineers Permit No.:199602789 (IP-CC)Extension
Date of Issue: May 8, 2008
Expiration Date: July 08, 2009
Project Description: This Permit authorized the extension of the expiration date for a period of one
year.
Department of Environmental Protection Permit/Extension No. 0128463-001-JC
Date of Issue: June 5,2008
Expiration Date: July 06, 2009
Project Description: This modification extends the expiration date for a period of one year.
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Department of Environmental Protection Permit No: 11-0128463-005
Date of Issue: December 17,2010
Expiration Date: December 17, 2015
Project Description: Continue maintenance activities to the hand-dug channels in the Clam Bay
system originally permitted under Permit No. 0128463-001-JC.
Department of the Army Corps of Engineers Permit No: SAJ-1996-02789 (IP-LAE)
Date of Issue: February 8, 2011
Expiration Date: February 8, 2021
Project Description: Continue maintenance activities to the hand-dug channels in the Clam Bay
system originally permitted under Permit No. 1996-02789 (IP-CC).
Department of Environmental Protection Permit No: 11-0295193-004
Date of Issue: November 2, 2011
Expiration Date: November 2,2016
Project Description: Install 32 canoe trail markers and informational signage.
Department of Environmental Protection Permit No: 0296087-001-JC
Date of Issue: August 14, 2012
Expiration Date: August 14, 2022
Project Description: Restore the alignment of Clam Pass to the previously approved location and
conducting periodic maintenance dredging of a portion of the Clam Pass Channel in order to maintain
tidal exchange between Clam Bay and the Gulf of Mexico.
United States Fish and Wildlife Service Biological Opinion Activity Code No: 41420-2010-CPA-0395
Date of Issue: February 22, 2013
Expiration Date: n/a
Project Description: FWS analysis of the potential effects of the dredging of the Pass on the threatened
piping plover (Charadrias melodus), threatened loggerhead sea turtle (Caretta caretta), endangered
Hawksbill (Eretmochelys imbricate), leatherback (Dermochelys coriacea), green (Chelonia mydas),
and Kemp's ridley (Lepidochelys kempii) sea turtles, and the endangered West Indian manatee
(Trichechus manatus).
Department of the Army Corps of Engineers Permit No: SAJ-1996-02789 (NWP-WDD)
Date of Issue: February 28, 2013
Expiration Date: March 18, 2017
Project Description: Dredging from Clam Pass and tidal creek to restore tidal exchange into Clam
Bay.
Department of Environmental Protection Permit Modification to Permit No: 0296087-002-JN
Date of Issue: March 1, 2013
Expiration Date: August 14, 2022
Project Description: Modification of August 2012 permit to re-open Clam Pass by mechanical
dredging of the Pass and flood shoal areas.
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5.0 Management Plan Goal and Supporting Objectives
The following goal and supporting objectives for the management of the Clam Bay Natural Resource
Protection Area were developed in accordance with the directives of the Collier County Board of
County Commissioners (BCC) and the Pelican Bay Services Division, which serves as an advisory
board to the BCC. The goal and supporting objectives were formed in conjunction with stakeholder
input and are based on the management issues present in the preserve as well as the purposes for which
the land is held in public trust. The document goal and supporting objectives set forth in this
Management Plan should not appreciably change over time but the management techniques and
activities proposed may be modified based on ongoing coordination with stakeholder and user groups
or when management objectives are not being met.
Management concerns are addressed in the following sections along with the management techniques
or activities proposed for addressing those concerns. The ability to implement specific goal objectives
presented in this Management Plan will be based on funding and staffing availability. The following
framework was identified during the stakeholder and PBSD committee meetings.
GOAL
The goal of the Clam Bay NRPA Management Plan is to protect, preserve, maintain, and
monitor the native floral and faunal communities to ensure protection and long-term
sustainability of the natural resources by incorporating, evaluating and prioritizing all relevant
information into a cohesive management strategy that supports compatible recreational activities
within its boundaries while protecting the long-term health of the ecosystem and its natural and
historical resources.
Objectives to support this goal include:
1. Maintain and protect the native floral and faunal communities within the Clam Bay
NRPA
2. Ensure the estuary has adequate tidal and freshwater flows to maintain ecological health
within the Clam Bay NRPA
3. Monitor, maintain, and protect water quality within the Clam Bay NRPA
4. Monitor archaeological sites within the Clam Bay NRPA
5. Ensure recreational activities are environmentally compatible within the Clam Bay
NRPA
These objectives were formed to allow for adaptive management, whereby the compilation and
analysis of all data will occur holistically and provide direction to adjust strategies to better achieve the
goal.
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Objective 1 - Maintain and protect the native floral and faunal communities within the Clam Bay
NRPA
A. Maintain healthy, native floral and faunal populations
Establish plots and photo points in Scrub and Hammock habitats and monitor annually
in conjunction with seagrass and mangrove monitoring.
*Monitor annually established plots in the mangroves.
*Monitor annually established transects in seagrasses.
*Document annually observed wildlife utilization.
*Add to current species lists as new species are sighted.
Conduct bird surveys as needed to keep species list current and in support of on-going
management activities.
Conduct fish surveys as needed to keep species list current and in support of on-going
management activities.
Monitor benthic organisms as needed in conjunction with planned management
activities or to update species lists.
*Compile and review monitoring results annually and make recommendations for
adapting management strategies as appropriate.
B. Protect Listed Species
Coordinate or collect gopher tortoise burrow data as needed to track population trends
within the NRPA boundary.
Coordinate with County to review and track sea turtle nesting data within the NRPA
boundary.
*Update listed species management practices as needed if species status changes.
*Conduct surveys as needed prior to disturbance events.
*Update educational information on species, such as the Clam Bay Field Guide, as
needed.
*Review listed species information annually and make recommendations for adapting
management strategies as appropriate.
C. Remove Exotic and Nuisance Flora and Fauna
*Locate and identify exotic, nonnative and nuisance species.
*Remove Category I and II invasive exotic species and nuisance species as appropriate.
*Report monitoring and maintenance activities in an annual report.
Make recommendations annually to improve conservation strategies.
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Objective 2 - Ensure the estuary has adequate tidal and freshwater flows to maintain ecological
health within the Clam Bay NRPA
A. Identify the minimum tidal flow necessary to ensure a healthy ecosystem. Provide
sufficient tidal exchange to maximize benefits while minimizing negative environmental
impacts.
Conduct bathymetric surveys of Clam Pass annually or as needed to document changes
that might necessitate management actions (i.e. dredging).
Conduct an initial bathymetric survey of interconnecting waterways between Inner,
Outer, and Upper Clam Bays and update as needed to document changes that might
necessitate management actions.
*Conduct, at minimum, an annual analysis of tidal data.
*Maintain tidal gauges in good working order. Consider upgrading to newer equipment
as technologies improve.
*Determine through regular biological monitoring whether ecological health warrants
intervention strategies.
Consider the need for dredging if data documents the need.
B.Ensure appropriate freshwater inputs and drainage
*Conduct annual monitoring of hand-dug channels.
*Perform annual maintenance of prioritized sections of hand-dug channels as funding
allows.
Monitor berm and spreader swale for adequate freshwater dispersal throughout the
system.
Consider the need for intervention strategies if data documents the need.
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Objective 3 - To monitor and maintain water quality within the Clam Bay NRPA
A. Develop a long-term water quality program that assesses physical, chemical and
biological processes to ensure a sustainable healthy environment for all users
*Continue program of monthly water quality data collection, making certain that it
complies with FDEP guidelines and standards and addresses the Site Specific
Criteria approved by FDEP.
*Report and review water quality data on a quarterly basis. Include comparison of
recent data to historical data.
Develop intervention strategies when results do not meet standards.
*Enter data into STORET system on an annual basis.
Develop plan to address copper impairment to Clam Bay.
B. Promote comprehensive programs for controlling water pollution from point and
nonpoint sources
*Continue to coordinate with Pelican Bay Foundation, PBSD Landscape and Water
Management Committee, and upland developments to reduce copper in upland
stormwater ponds in Pelican Bay.
*Continue to work with Pelican Bay Foundation, PBSD Landscape and Water
Management Committee, and upland developments to reduce the application of
fertilizers in Pelican Bay.
*Continue to work with PBSD Landscape and Water Management Committee to
increase the use of best management practices in Pelican Bay.
Develop a plan to determine the impact of upland land use on water quality in the Clam
Bay NRPA.
Objective 4—Monitor archaeological sites within the Clam Bay NRPA
A. Monitor conditions of known archeological sites.
Review historical records of Florida Division of Historical Resources (DHR) on known
archeological sites.
Establish baseline conditions of known archeological sites.
Inspect known archeological sites at least annually.
Report disturbances or looting as appropriate to DHR.
B. Implement strategies for protecting archeological sites as needed.
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Objective 5 - Ensure recreational activities are safe and environmentally compatible within the
Clam Bay NRPA
A. Monitor access points into NRPA for recreational uses.
Inspect boardwalks as needed for mangrove encroachment and potential trimming
activities.
Report vegetation or litter needing to be trimmed or removed to responsible entity.
Report facilities needing repair or replacement to responsible entity.
B. Maintain existing canoe trail.
Inspect signage at least annually.
Repair/replace signage as needed.
Revise/reprint canoe trail guide as needed.
C. Maintain existing signage for safe swimmer and boater usage.
Inspect signage at least annually.
Repair/replace signage as needed.
D. Monitor and document improper use of NRPA.
Establish a mechanism for citizens to report incidents of unlawful, unsafe and/or
environmentally harmful use.
Coordinate with Collier County Sheriff's Department as appropriate.
Develop materials to guide recreational use as needed.
E. Maintain materials to educate visitors about the unique features of the Clam Bay
NRPA.
Report signage needing repair/replacement to responsible entity.
Develop new educational materials as needed.
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Clam Bay NRPA Management Plan Amendments
Studies within the Clam Bay Estuary as well as in other similar local ecosystems are either ongoing or
expected to occur within the asked for time frame of this document. The Management Plan is not
expected to be a static document and ongoing research and data collection related to water quality;
hydrographic changes in the various areas of the system; benthic community health; mangrove
community health; exotic and nuisance vegetation control; and public education will be conducted
and/or collected. Conclusions, recommendations, or alternative management activities that come about
as a result of studies conducted outside of the scope of this Management Plan will be examined and
considered by the Pelican Bay Services Division and its consultants. Those modification that are
found to be viable,pertinent, and economically feasible alternatives or additions allowed under the
scope of this Management Plan will be added to the Management Plan. Those changes in management
activities or new work items that are outside of the scope of the Management Plan but are considered
important or practicable by the Pelican Bay Services Division and its consultants will be submitted to
FDEP and the USACE for consideration and inclusion into this Management Plan.
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April 24,2014 Clam Bay Committee of the Pelican Bay Services Division
Submitted by Susan O'Brien,April 18,2014
Minor edits
p. 1 par. 2 line 9 make it the goal and objectives.
p. 1 par. 4 line 3 add of after implementation
p. 3 par 1 line 2 change to "interested citizens" from concerned citizen's groups
p. 5 par 2 line 2 make it Wiggins
p. 5 par 4 line 1 use colon instead of semicolon
p. 7 par 1 line 1 make it Clam Bay NRPA
P. 7 par 2 line 9 add a comma after property
p. 62 par 1 line 4 delete comma after information
Stakeholder list for USACE change to Royal; for US Fish and Wildlife change to Beach; for Sierra Club make
it Calusa Group of the Sierra Club; Consider adding Annice Gregerson (Annice@comcast.net)who has
attended many meetings. You may also want to list Mary Johnson, a PBF Board member, either under the PBF
or separately because she has attended many meetings.
Organizational edits
Table of Contents- Page numbers and list of materials in appendices are needed.
3.0 Table of Contents uses Resource Descriptions and on page 17 Resource Descriptions and Assessment is
used as the heading.
Insert the heading Exotic Species, perhaps on page 43, because it is used in the Table of Contents.
Insert the heading Other Wildlife Species in text because it appears in the Table of Contents
Substantive edits
p. 5 par. 4 lines 6 &7 Delete"The operation of motorized watercraft is limited to idle speed/no wake per
Collier County Ordinance 96-16" and substitute "Under Florida statute 327. 46,the speed of motorized vessels
in areas of the Clam Bay NRPA can be restricted to either idle speed/no wake or slow speed/minimum wake
through the enactment of Collier County ordinances with the approval of the Florida Fish and Wildlife
Conservation Commission."
p. 8 par. 1 line 3. Consider adding, "Collier County's Department of Parks and Recreation oversees the
management of this park. Through an agreement between the County and the hotel near the park, much of the
day-to-day operation of the park is provided by the hotel."
p. 63 par. 2 Delete par. and add "The use of motorized vessels is restricted by the ephemeral nature of Clam
Pass and the shallow waters of the bay system (Collier County Manatee Protection Plan, 1995). Under Florida
statute 327.46 the speed of motorized vessels in areas of the Clam Bay NRPA can be restricted to either idle
speed/no wake or slow speed/minimum wake through the enactment of Collier County ordinances with the
approval of the Florida Fish and Wildlife Conservation Commission."
p. 70 par 3 edit goal so it reads, "The goal of the Clam Bay NRPA Management Plan is to protect,preserve,
maintain and monitor the native floral and faunal communities to ensure protection and long-term sustainability
of the natural resources by incorporating, evaluating, and prioritizing all relevant information into a cohesive
management strategy that supports compatible recreational activities within its boundaries while protecting the
long-term health of the ecosystem and its natural and historical resources."
April 24,2014 Clam Bay Committee of the Pelican Bay Services Division
AN ORDINANCE RELATING TO VEESSEL CONTROL AND WATER
SAFETY IN THE CLAM BAY SYSTEM; PROVIDING FOR INTENT
AND PURPOSE; PROVIDING TITLE AND CITATION; SETTING
FORTH APPLICABILITY; PROVIDING FOR VESSEL SPEED
REGULATION; PROVIDING DEFINITIONS; PROVIDING
PENALTIES; PROVIDING FOR ENFORCEMENT; PROVIDING
FOR CONFLICT AND SEVERABILITY; AND PROVIDING AN
EFFECTIVE DATE.
WHEREAS,Collier County, pursuant to Section 327.4668(1)(b)(1),(1)(c)(1) and
(1)(c)(2)(c),Florida Statutes (as amended),has the legal authority to adopt this Ordinance
to ' restrict vessel speeds on waterways in the unincorporated areas
of the County; and
WHEREAS,the Collier County Manatee Protection Plan, adopted by the Collier
County Board of County Commissioners on May 23,1995, has identified-recommended the
Clam Bay System as an idle speed zone; and
WHEREAS,it is necessary that the speed and operation of vessels located in the
Clam Bay System as specified herein be controlled in order to protect manatees an`' their
habitntthe safety of the public; and
WHEREAS,the Clam Bay System has been designated as a Natural Resource
Protection Area in Collier County and
WHEREAS, it is in the interest for the safety and welfare of the canoeing public,
kayakers, and small boat operators, that certain controls and regulations be enacted to
reduce risk and injury to the canoeing public, kayakers, and small boat operators and
ensure the enjoyablity of these natural resources by the general public.
NOW,THEREFORE,BE IT ORDAINED BY THE BOARD OF COUNTY
COMMISSIONERS OF COLLIER COUNTY,FLORIDA,that:
SECTION ONE: INTENT AND PURPOSE
It is the intent and purpose of this Ordinance to protect and promote the health,
safety,and welfare of the public,including residents and visitors to Collier County and in
particular to the Clam Bay area by providing reasonable regulation to the operation of
vessels as defined. It is further intended that this ordinance shall be liberally construed to
effect such intent and purpose.
1
to\ e*6,
C°'
LApril 24,2014 lam Bay Committee of the Pelican.ay Services Division
006
it" )614 *
‘ I* \ ..4444? ‘ .
SECTION TWO: TITLE AND CITATION ` `
This Ordinance shall be known and be cited as the"Clam Bay System Water Safety
and Vessel Control Ordinance."
f
't
SECTION THREE: APPLICABILITY , 4,.
This Ordinance shall apply to and be enforced on all the waters of the following
described Restricted Areas:
1. The Clam Bay System including the interconnecting watenvays between Upper
Clam Bay,Inner Clam Bay,Outer Clam Bay,and Clam Pass. ‘..,,,,.,
. The restricted areas are as specified on the map attached hereto as
"Exhibit A."
2. Reserved. .�•
k., \-:.
SECTION FOUR: VESSEL SPEED REGULATION
Except during an emergency or operation by an official of the government y; hilei
engaged in official business,the operation of any vessel in excess of idle speed, as defined
herein,within 500 feet of the kayak launch area or en-within any-the shallow waterk
d,
limited visibility interconnecting waterways f th Clam Ba.,Syst ��between Outer Clam
Bay,Inner Clam Bay,and Clam Pass is hereby prohibited and is a violation of this
Ordinance. The operation of any vessel in excess of slow speed within the waterway
between Clam Pass and Outer Clam Bay is also hereby prohibited and is a violation of this
ordinance. Said prohibitions isare effective and enforceable provided the"no-Fakeidle
speed" ans"slow speed" areas is-are designated by regulatory marker, signage, buoy, or
any other notice of the "no wakeidle speed" or"slow speed" status. The locations of such
notices shall be placed at the discretion of the County Staff. All such notices posted by the
County are official notices of the County. It is no defense to a violation of this Ordinance to
allege that the Defendant did not observe notice of the " eidle speed" or"slow
speed" status of the waters of the Clam Bay System.
SECTION FIVE: DEFINITIONS
For the purposes of this Ordinance,the following words are defined as follows:
A. IDLE SPEED means the minimum speed through or over the surface of the water
that will allow the vessel operator to maintain steerage of the vessel.
2
April 24,2014 Clam Bay Committee of the Pelican Bay Services Division
B. OPERATE means to be in control of the speed of a vessel traveling over or in water.
C. VESSEL means a motor propelled and/or artificially propelled boat,sailboat, barge,
airboat or other watercraft used or capable of being used as a means of transportation of
one ( 1) or more persons over or in the water,whether propelled by wind, propeller,or
forcing flow of water by propeller or impeller, or otherwise. Vessel does not include a
canoe,kayak, or similar small minimum wake type vessels provided the vessel is then being
propelled only by paddle and not by motor,pump, or sail. "Vessel" does not include
seaplane.
SECTION SIX: PENALTIES
Each violation of this Ordinance is a civil infraction. If a Citation of Violation is not
contested and is paid in full and on time,the fine shall be fifty dollars ($50.00) for the first
violation within any six (6) month period, and one hundred dollars ($100.00) for a second
violation by the same person within any one(I)year period. If the fine is not paid in full
and on time,the Court may impose a fine of up to five hundred dollars ($500.00) plus court
costs and any other costs and/or fees authorized to be imposed by the Court by Florida
Statutes. As an alternative means of enforcement,violations of this Ordinance may be
referred to the Collier County Code Enforcement Board.
SECTION SEVEN: ENFORCEMENT
The provisions of this Ordinance shall be enforced by any member of any duly
authorized law enforcement agency or officers having enforcement jurisdiction in Collier
County,Florida. Civil Citations may be used to notify the defendant of allegations of
violations of this Ordinance.
SECTION EIGHT: CONFLICT AND SEVERABILITY
In the event this Ordinance conflicts with any other ordinance of Collier County or
other applicable law,the more restrictive shall apply. If any phrase or portion of the
Ordinance is held invalid or unconstitutional by any court of competent jurisdiction, such
portion shall be deemed a separate distinct and independent provision and such holding
shall not affect the validity of the remaining portion.
SECTION NINE: INCLUDSION IN THE CODE OF LAWS AND ORDINANCES
The provisions of this Ordinance shall be come and be made a part o the code of
Laws and Ordinances of Collier County,Florida. The Sections of the Ordinance may be
renumbered or relettered to accomplish such,and the word "ordinance" may be changed
to"section," "article," or any other appropriate word.
3
April 24,2014 Clam Bay Committee of the Pelican Bay Services Division
SECTON TEN: EFFECTIVE DATE
This ordinance shall take effect upon filing with the Secretary of State.
PASSED AND DULY APDOPTED BY THE Board of County commissioners of
Collier County,Florida,this day of ,20
4
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_4
April 24,2014 Clam Bay Committee of the Pelican Bay Services Division
Submitted by Susan O'Brien,April 22,2014
Possible New Reports/Activities for Clam Bay for FY 2015
Inspect archeological sites $ 750
Monitor gopher tortoise burrows 3,750
Conduct surveys 5,000
Monitor plots in scrub and hammock habitats 6,000
Inspect canoe trail and Clam Bay signage 300
Monitor upland activities that could affect flow 600
Promote educational information re: exotic and nuisance species 700
Monitor sea turtle nesting
Coordinate with Collier County and Waldorf 500
re: vegetation and litter control
Biological activities/reports 17,600
Bathymetric survey of Clam Pass (annual) 28,000
*Bathymetric survey of interconnecting waterways (initial)
*Cost estimate to be provided at meeting
Engineering
` d ' (tel
�J of
Worley's article on the reasons to dredge and Dr.�abees' i 5
Suggested language from Kathy y M�
April,2014 report ( I ,
When and why to dredge Clam Pass li d-'t
AI
There are two circumstances that could necessitate dredging. GCS"" .e
cp
nn
The first is if Clam Pass closes completely due to a storm or natural event or is in eminent
danger of immediate closure following a weather-driven event In this situation the inlet
should be dredged as soon as possible.
The second is if the inlet has lost hydraulic efficiency that is not recoverable through
natural processes,and the health of the estuary is in jeopardy. This determination is made
by reviewing and comparing current and past data on tidal hydraulic monitoring as well as
data on the present health of the floral and faunal communities of the Clam Bay NRPA.
In both cases the Pelican Bay Services Division Board would approve and recommend an
appropriate set of construction drawings for the dredging event to the Board of County
Commissioners for its approval prior to their submittal to the regulatory agencies.
Dredging will only be done for the health of the Clam Bay NRPA,not for navigation or sand
for area beaches.
Monitoring Clam Pass
The purpose of regular monitoring is to evaluate inlet characteristics on a comprehensive
long-term basis with less emphasis on short-term or seasonal changes.
Data on the below-listed variables will be regularly,collected and used to determine if
dredging is needed.
Bay Tide Range
Tidal data have been collected annually since 1999 and will continue to be collected and
reported to the consulting engineer monthly. An annual tidal analysis report will continue
be completed.
Data are collected from gauges at four locations (Class Pass Park Boardwalk,Pelican Bay
South Boardwalk,Pelican Bay North Boardwalk,and Upper Clam Bay). These gauges
provide a record of the tidal range in the bay which is a indicator of the tidal prism or
volume of water flowing through Clam Pass at each tidal cycle.
Based on an analysis of data from the gauges at the South Boardwalk and the Clam Pass.
Park Boardwalk from 1998 to the present when the inlet was hydraulically stable,the ratio
between the bay and gulf tide was between 0.6 to 0.7 over 90%of the time. Therefore,if
the ratio between the bay and gulf tide falls below 0.6,further monitoring and/or
intervention may be needed. See pages x and y for additional information(pages 5&6
from April,2014 H&M report.)
1
Cross Section of Flow Area
Annual bathyme'cric surveys and reports were done from 1999 to 2008. Post-dredging
bathymetric surveys and reports were completed at 3-month,6-month,and 12-month
intervals following the opening of Clam Pass in April,2013. Going forward bathymetric
surveys and reports will be completed at least annually. Bathymetric surveys provide data
on the physical conditions of the inlet channel,flood shoal and ebb shoal.
To establish benchmarks for this variable the data analysis included evaluation of the flow
cross-section areas in the three main sections of the dredging template. Section A
represents the inlet channel; Section B the seaward part of the flood shoal; and Section C
the bay side part of the flood shoal. The analysis included evaluation of the cross section of
flow between mean high water and the volume of sand within each segment.The cross
section of flow was computed at each survey station spaced approximately 50 feet apart.
The average and minimum cross section areas were used as indicators of the physical
condition of the flow area of the three segments. The cross sections were compared to the
design cross section area of the 2013 dredging and the inlet conditions in 2004 and 2008
when inlet conditions were near equilibrium 24 months and 16 months,respectively,
following a dredging event.
Benchmarks for the average cross-section of flow areas are as follows:
Section A greater than 300 sq ft.
Section B greater than 450 sq ft
Section C greater than 400 sq ft.
Therefore,if the average cross-section of flow area falls below these numbers,further
monitoring and/or intervention may be needed.
See pages x for additional information. (pages 12, 16 and 22 from April,2014 H&M
report.)
Inlet Channel Length
The channel length is an important factor in the inlet stability parameters. A longer inlet
channel will provide greater resistance to flow. Higher flow resistance will reduce the tidal
range and increase the phase lag with the gulf tide which reduces the tidal prism and flow
through Clam Pass.
To establish a benchmark for channel length a selection of aerial photos of Clam Pass from
2004 to 2013 were studied as well as data on the approximate length of the channel
following dredging events in 2002,2007,and 2013.
Based on this analysis,the benchmark for inlet channel length is less than 400 feet. See
pages x,y&z (pages 24, 25, 26 from April,2014 H&M report.
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Ebb Shoal
The size and shape of the ebb shoal is a key factor to the stability of the inlet that supports
the stability of Clam Pass. The ebb shoal helps to keep the inlet open when facing storms
and big wave events. The ebb shoal delta provides sheltering to the channel and sand
bypass pathway around the inlet without filling in the Pass. The shape and volume of the
ebb shoal are additional indicators of the stability of the inlet. Ebb shoal critical conditions
include onshore collapse of the ebb shoal that can be indicated by significant change in ebb
shoal offshore distance,volume,and increase in dry beach areas adjacent to the inlet.
The recommended length of the seaward extent of the ebb shoal is less than 250 feet.
Therefore,if the length becomes more than 250 feet,further monitoring and/or
intervention may be needed. See page x for additional information. (page 27 from April,
2014 H M report)
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