PBSD Clam Bay Committee Agenda 03/12/2020 PELICAN BAY SERVICES DIVISION
Municipal Service Taxing and Benefit Unit
NOTICE OF PUBLIC MEETING MARCH 12, 2020
THE CLAM BAY COMMITTEE OF THE PELICAN BAY SERVICES DIVISION WILL
MEET AT 1:30 PM ON THURSDAY, MARCH 12 AT THE PELICAN BAY SERVICES
DIVISION, 3RD FLOOR OF THE SUNTRUST BUILDING, SUITE 302, LOCATED AT 801
LAUREL OAK DRIVE, NAPLES, FLORIDA 34108.
AGENDA
1. Roll call
2. Agenda approval
3. Approval of 01/09/2020 meeting minutes
4. Audience comments
5. Water Quality
a. Copper results
b. Second and third water quality report
c. 2019 Annual Water Quality Report
6. Clam Pass
a. February tidal ratio report
b. Video of H&M report
c. Timeline for dredging-related activities
7. Clam Bay
a. Update on monitoring
b. Hand-dug channel maintenance
c. Canoe trail marker 6 signage
d. Scaevola treatment proposal
e. Update on County boater safety signage
8. Beach Renourishment
a. County Survey Results
b. Update on County Beach Resiliency program
9. Draft of FY2021 Clam Bay Budget
10. Next meeting: May 12 or 14, 2020
11. Adjournment
*Reports are available on PBSD's website. Copies may be requested.
ANY PERSON WISHING TO SPEAK ON AN AGENDA ITEM WILL RECEIVE UP TO THREE (3) MINUTES 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
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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.
03/05/2020 10:26 AM
PELICAN BAY SERVICES DIVISION
CLAM BAY COMMITTEE MEETING
JANUARY 9, 2020
The Clam Bay Committee of the Pelican Bay Services Division met on Thursday, January 9 at
1:30 p.m. at the SunTrust Bank Building, 801 Laurel Oak Drive, Suite 302,Naples,Florida 34108.
In attendance were:
Clam Bay Committee Denise McLaughlin
Susan O'Brien, Chairman Rick Swider
Pelican Bay Services Division Staff Lisa Jacob, Project Manager
Neil Dorrill, Administrator Barbara Shea, Interim Operations Analyst
Chad Coleman, Operations Manager
Also Present
Jennifer Bobka, Earth Tech Mohamed Dabees, Humiston & Moore
APPROVED AGENDA (AS AMENDED)
1. Roll call
2. Agenda approval
3. Approval of 11/14/19 meeting minutes
4. Audience comments
5. Clam Bay
a. 2019 Monitoring Report*
b. Canoe trail marker 6 signage
c. Scaevola treatment proposal
d. Tidal gauge at marker 26
e. Update on County boater safety signage
6. Clam Pass
a. 2019 Physical and Tidal Monitoring Report*
b. December tidal ratio report
c. Video of H&M report
d. Timeline for dredging-related activities
6.5.Beach Renourishment (add-on)
7. Water Quality
a. Copper results
b. Second and third water quality report
c. 2019 Annual Water Quality Report
d. FDEP Water Quality findings
8. Next meeting: March 12 or 13, 2020
9. Adjournment
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Pelican Bay Services Division Clam Bay Committee Meeting
January 9,2020
ROLL CALL
All members were present and a quorum was established
AGENDA APPROVAL
Ms. McLaughlin motioned, Ms. O'Brien seconded to approve the agenda as
amended with the addition of agenda item#6.5. The motion carried unanimously.
APPROVAL OF 11/14/19 MEETING MINUTES
Ms.McLaughlin motioned,Ms. O'Brien seconded to approve the 11/14/19 meeting
minutes as presented. The motion carried unanimously.
AUDIENCE COMMENTS
Mr. Joel Johnson, President of Beach Renourishment, Inc. commented on his beach
renourishment patent pending product which utilizes wind and waves. He requested a future
discussion of beach renourishment with the committee.
CLAM BAY
2019 MONITORING REPORT
Ms. Bobka, Environmental Consultant with Earth Tech,provided a discussion of the 2019
Annual Clam Bay Monitoring Report, including recommendations. Highlights included:
• Clam Bay annual monitoring revealed no stark red flags.
• Overall,the mangroves are demonstrating further recovery since Hurricane Irma.
• A few areas showing mangrove distress are a result of a lack of nearby drainage.
• Annual hand-dug channel maintenance is recommended to be continued.
• Overall seagrass acreage is slightly down; however, certain areas are exhibiting greater
density.
• Drone aerial footage has identified four new areas of stressed mangroves; two of the areas
are in transition from black to red, and the other two areas will be monitored closely.
• A reduction in the number of gopher tortoise burrows was observed. This may be in
response to Hurricane Irma, which caused a shifting of burrows eastward.
• Extensive scaevola has been mapped.
SCAEVOLA TREATMENT PROPOSAL
Ms. O'Brien commented that we will be looking at future funding for scaevola removal
which hopefully will be included in the FY2021 PBSD budget. She questioned whether we could
piggyback any similar County scaevola removal project, County contract, or grant opportunity.
TIDAL GAUGE AT MARKER 26
Ms. O'Brien commented that tidal gauge marker 26 is still down. Mr. Coleman confirmed
that Locher will schedule an inspection of this tidal gauge shortly.
UPDATE ON COUNTY BOATER SAFETY SIGNAGE
Ms. O'Brien commented on a staff meeting with Chris D'Arco (County Coastal Zone
Management)and our Environmental Consultant Tim Hall to discuss boater safety signage in Clam
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Pelican Bay Services Division Clam Bay Committee Meeting
January 9,2020
Bay. She suggested that staff documents the details of the meeting discussion and what our
expectations are as a result of this discussion.
CLAM PASS
2019 PHYSICAL AND TIDAL MONTORING REPORT
Ms. McLaughlin requested that the final 2019 Physical and Tidal Monitoring Report be
posted on the PBSD website, replacing the existing "draft"report.
Dr. Dabees,Environmental Consultant with Humiston and Moore provided a discussion of
the annual 2019 Physical and Tidal Monitoring Report. Highlights included:
• Tidal ratios remained very steady throughout 2019.
• Existing sand in the template is approximately the same magnitude as last year.
• Indicators are stable; we will continue to monitor on a monthly basis.
• The annual bathymetric survey is scheduled for May 2020; a spot check will occur in Dec.
• An ebb shoal visible at low tide should correct itself over the near-term.
Ms. O'Brien provided a document entitled "Clam Pass Dredging, Total Volume of Sand"
to the committee, which was added to the record. This document shows the volume of sand in
Sections A, B, and C at five different times during the past two years. Dr. Dabees commented on
the data and noted the stability of the volume of sand from 11/6/18 through 11/22/19.
DECEMBER TIDAL RATIO REPORT
Dr. Dabees commented that tidal ratios continue to remain steady.
VIDEO OF H&M REPORT
Mr. Dorrill made a note to follow up on producing a video of the H&M Report on Clam
Pass dredging (previously presented to the County Manager's Office and Commissioner Solis).
TIMELINE FOR DREDGING-RELATED ACTIVITIES
Dr. Dabees commented that he has been working with Ms. Jacob on a timeline of the
activities required to complete a maintenance dredging event. A general discussion of the timeline
for such an event included the following highlights:
• The beginning of the timeline is triggered either by the monthly tidal ratios or by the May
bathymetric survey.
• It takes 6—9 months to get a dredging contractor in place.
• Ideally, work would begin in early winter and end before the following spring; sea turtle
nesting season from April—October must be accommodated.
• A dredging event requires approval by the PBSD Board,the PBF Board,the TDC, and the
Board of County Commissioners.
• Both a maintenance dredge and an emergency dredge are an"eligible use" for TDC funds.
• The benefits from maintaining the health of Clam Pass and the mangroves are priceless.
• Generally,the sand from a dredging event is placed on the south side of Clam Pass. When
sand is placed on the PBF beach, the PBF is required to pay for the sand.
Ms. Jacob commented that she is in the process of completing her work on the dredging
timeline and will provide it to the committee at the next committee meeting. She also commented
that based on a recent conversation with the County Procurement Dept., it will not be possible to
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Pelican Bay Services Division Clam Bay Committee Meeting
January 9,2020
pre-qualify dredging contractors. Going through the process of pre-qualifying dredging
contractors would most likely increase our dredging costs.
BEACH RENOURISHMENT (ADD-ON)
Ms. O'Brien commented that at the Jan. 8 board meeting, it was suggested that beach
renourishment may become a responsibility of the Clam Bay Committee. Dr. Dabees provided a
discussion of the beach renourishment process; highlights included:
• If Vanderbilt Beach is healthy, over time, our PB northern beaches will be healthy.
• It is ill advised to do a North Beach project without a Vanderbilt Beach project; it is most
cost-effective to piggyback a Vanderbilt Beach project. Sand will disappear if an isolated
project is completed.
• If infrastructure is vulnerable,only then could a project be completed in isolation,and only
as a stop-gap measure.
• The TDC funds beach renourishment for public beaches, not private PB beaches.
• The County's Coastal Zone (CZM) Dept. measures and monitors all County beaches.
Ms. Mary Johnson commented that the County added the beach renourishment
responsibility to the PBSD in 2013. She commented in favor of adding the beach renourishment
responsibility to the Clam Bay Committee.
Ms. O'Brien commented that former PBSD Board member, Dr. Trecker in past years
would provide information he received from the CZM Dept. to the Beach Renourishment
Committee as Chairman of this committee. She asked if staff could request a representative from
the CZM Dept. to attend the next Clam Bay Committee meeting and provide information on their
future beach renourishment plans, including an update on their super-renourishment plans.
Mr. Dorrill commented that staff receives the annual beach width survey completed by the
CZM Dept. Dr. Dabees commented that the CZM Dept. has the state permits for beach
renourishment, and that the PBSD should ensure that we have the appropriate permits to be
eligible to be included in a County project.
Dr.Dabees commented that he would be happy to provide a tutorial on beach survey results
to Ms. McLaughlin, at her convenience.
Ms. McLaughlin motioned, Ms. O'Brien seconded that beach renourishment is
added to the responsibilities of the Clam Bay Committee. The motion carried
unanimously.
WATER QUALITY
COPPER RESULTS
Ms. O'Brien commented that the copper results provided are the same as those provided in
the last meeting's agenda packet.
SECOND AND THIRD QUARTER WATER QUALITY REPORT
Ms. O'Brien commented that we have not received Dr. Tomasko's final 2nd and 3rd quarter
combined water quality report.
2019 ANNUAL WATER QUALITY REPORT
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Pelican Bay Services Division Clam Bay Committee Meeting
January 9,2020
Ms. O'Brien commented that the final Tomasko 2019 annual water quality report is
pending.
FDEP WATER QUALITY FINDINGS
Ms. O'Brien provided a document entitled "FDEP Water Quality Findings— Clam Bay —
June 25, 2019," which was added to the record. She noted that she has had a discussion on these
findings with Ms. Rhonda Watkins, in the County's Pollution Control Dept.
PHOSPHORUS LEVELS IN CLAM BAY
Ms. McLaughlin commented on her recent discussion with the Conservancy regarding
possible methods to reduce phosphorus levels in Clam Bay. She commented that they
recommended that we recommend an absolute ban on fertilizer during the rainy season (although
this is not in the County ordinance). Ms. Johnson commented on the appropriateness of the site-
specific FDEP standard for phosphorus levels in Clam Bay.
Ms. McLaughlin commented on her recent discussion with Dr. Trecker, who commented
on a Clam Bay sedimentation analysis completed five years ago which revealed a significant
amount of phosphorus in the sediment. Dr. Trecker concluded that (1) sediment phosphorus
continuously goes back into solution, (2) it is not realistic to see any improvement as a result of
the phosphorus contained in the sediment,and(3) elimination of phosphorus in fertilizer may only
provide a slight amount of improvement in phosphorus levels.
NEXT MEETING:
By consensus,the committee agreed that the next meeting of the committee would be held
on Mar. 12, 2020 at 1:30 p.m.
ADJOURNMENT
The meeting was adjourned at 3:20 p.m. I
Susan O'Brien, Chairman
Minutes approved [ ] as presented OR [ ] as amended ON [ ] date
5
Agenda item#5a
Page 1 of 1
Clam Bay Copper ug/L
Collection Date CB1 CB2 CB3 CB4 CB5 CB6 CB7 CB8 CB9 Report Date
6/22/2016 0.862 0.700 0.700 0.700 1.640 2.100 0.700 3.520 1.510 9/8/2016
7/20/2016 0.924 5.330 5.110 5.660 2.470 3.960 4.950 5.710 10.500 9/12/2016
7/20/2016 0.924 6.160 4.700 1.690 2.470 1.830 1.980 1.870 8.360 9/21/2016
8/25/2016 2.000 1.850 1.680 1.470 1.240 1.520 2.250 1.280 8.060 10/4/2016
9/20/2016 1.690 2.280 1.280 1.760 0.751 0.700 0.700 1.030 0.700 11/22/2016
10/12/2016 2.760 2.200 2.130 1.190 2.900 1.860 1.060 0.954 1.310 12/7/2016
11/9/2016 2.340 3.390 2.300 2.250 1.630 1.500 1.180 2.030 1.300 1/16/2017
12/6/2016 2.330 2.930 5.100 2.450 2.390 1.780 1.270 1.880 1.720 3/14/2017
1/19/2017 2.570 3.560 2.110 1.990 0.818 0.800 0.961 1.110 2.020 4/4/2017
2/23/2017 2.510 3.350 1.600 1.120 0.851 0.848 1.500 2.570 2.600 4/24/2017
3/21/2017 7.970 4.080 1.710 1.120 0.894 0.846 1.080 1.090 0.957 6/1/2017
4/18/2017 6.480 8.160 1.620 1.240 0.800 0.956 1.280 1.010 1.100 6/14/2017
5/24/2017 2.840 4.060 4.990 0.800 0.800 0.959 0.800 0.920 0.946 7/6/2017
6/21/2017 3.840 4.240 3.850 0.906 1.200 1.140 1.260 1.110 0.760 8/8/2017
7/13/2017 4.700 2.950 3.800 4.080 2.500 2.440 2.370 2.380 2.210 8/29/2017
8/14/2017 4.290 3.810 3.220 2.650 1.400 1.220 1.470 1.020 0.700 10/10/2017
10/4/2017 2.680 1.270 0.600 0.800 12.600 1.610 0.600 0.600 1/22/2018
11/28/2017 0.700 0.722 2.540 0.700 0.700 0.700 0.700 0.700 0.700 1/22/2018
12/12/2017 1.780 2.250 1.890 0.700 1.210 1.210 1.300 0.728 0.911 3/26/2018
1/8/2018 0.420 1.510 1.690 1.590 0.800 0.809 0.800 0.800 2.400 4/27/2018
2/6/2018 3.400 3.980 2.130 2.420 0.829 1.640 3.920 0.800 0.800 4/30/2018
3/22/2018 5.450 4.890 3.670 2.370 1.010 1.040 1.750 1.010 1.320 5/11/2018
4/4/2018 2.370 3.190 2.380 1.970 1.690 0.848 1.280 1.250 5.160 6/11/2018
5/8/2018 5.490 4.880 2.360 1.090 0.800 1.050 1.270 1.570 1.640 7/2/2018
6/6/2018 3.120 3.320 2.670 0.800 0.800 0.853 0.828 1.080 1.220 7/18/2018
7/17/2018 1.400 1.440 1.600 1.600 2.270 1.600 1.600 1.600 1.600 8/21/2018
8/15/2018 1.500 1.410 1.400 1.400 1.600 1.600 1.600 1.650 1.600 10/8/2018
9/13/2018 1.720 1.960 1.200 1.200 1.400 1.400 1.400 1.600 1.400 10/9/2018
10/15/2018 3.190 4.800 4.400 4.030 1.400 1.400 1.960 1.400 1.400 12/21/2018
11/14/2018 1.750 1.900 1.960 1.600 1.600 1.600 1.600 1.600 1.600 2/28/2019
12/12/2018 4.480 2.790 2.400 1.820 1.600 1.600 1.600 1.600 1.600 2/28/2019
1/14/2019 3.150 2.740 2.100 1.880 1.600 1.600 1.600 1.600 1.600 5/3/2019
2/25/2019 3.420 2.470 2.000 1.940 1.600 1.600 1.600 1.600 1.600 5/3/2019
3/25/2019 1.830 3.090 1.600 2.730 1.600 1.600 1.600 1.600 1.600 5/14/2019
4/11/2019 2.310 2.530 1.720 1.910 1.600 1.600 1.600 1.600 1.600 8/8/2019
5/9/2019 2.290 3.160 2.030 2.720 1.600 1.600 1.600 1.600 1.600 8/8/2019
6/25/2019 3.030 2.460 1.720 1.600 1.600 1.600 1.600 1.400 1.450 8/8/2019
7/24/2019 2.660 2.020 1.770 1.600 1.400 1.400 1.400 1.400 1.660 10/1/2019
8/8/2019 2.760 1.710 2.100 2.090 1.400 1.400 1.400 1.400 1.400 10/1/2019
9/5/2019 2.030 1.410 1.400 1.400 1.400 1.400 1.400 1.400 1.400 10/1/2019
10/21/2019 1.870 2.120 1.950 1.450 1.430 1.600 1.600 1.600 1.600 1/13/2020
11/19/2019 1.400 1.600 1.600 1.600 1.600 1.600 1.600 1.600 1.600 1/13/2020
12/16/2019 3.030 3.940 2.310 1.810 1.600 1.600 1.600 1.600 1.600 1/13/2020
Agenda item#5b
Page 1 of 7
memorandum
date February 18, 2020
to Tim Hall, Turrell, Hall and Associates, Inc.
from David Tomasko, Ph.D.
Emily Keenan, M.S.
subject Quarter 2 and 3: Clam Bay NNC SSAC evaluation
Background
The United States Environmental Protection Agency and the Florida Department of
Environmental Protection Agency (FDEP) adopted site specific alternative nutrient criteria
(SSAC) for Clam Bay, as listed in Florida Administrative Code (FAC) 62-302.531. The SSAC
were derived based upon a nutrient: salinity relationship from the Estero Bay Wetlands, a
reference waterbody for water quality, as established by FDEP in prior TMDLs. The SSAC for
Clam Bay is considered in the context of specific conductance, which is directly related to salinity.
The reason for this is that nutrient concentrations vary with the amount of freshwater influence,
even in watersheds with no human impacts. The Clam Bay NNC criteria are constructed in such
a manner that changes in nutrient concentrations that are likely due to variation in rainfall alone
are identified, so that the focus can remain on changes in nutrient concentrations due to sewage
spill
Based on prior work that showed that phytoplankton growth in Clam Bay was likely stimulated
by both Total Nitrogen (TN) and Total Phosphorous (TP), both TN and TP are used to determine
the degree of nutrient enrichment of Clam Bay's waters. As outlined in FAC 62-302.531, water
quality status is determined on an annual basis, preferably within a calendar year. Within a
calendar year, each individual TN and TP value collected within the waterbody is compared to
the nutrient: conductivity 90th percentile prediction limit (Figure 1), and an annual percent
exceedance is calculated to determine the magnitude of exceedances per year. To be consistent
with the method currently implemented by FDEP to identify impaired water bodies, if 13 percent
or more of the TN or TP values in a calendar year exceed the 90th percentile prediction limit
(after being normalized for conductivity) the duration of exceedance is then determined. Based
on the duration of exceedance (one year or greater than one year), the outcome designation is
assigned. If fewer than 13 percent of the values exceed the 90th percent prediction limit, then
the outcome is "0". If the magnitude (i.e., 13 percent) and duration (i.e., less than 1 year) of the
exceedances are deemed small, the outcome is "1". If the magnitude or duration of the
exceedances is large, then the outcome is "2". If both the magnitude and duration of the
Agenda item#5b
Page 2 of 7
exceedances are large, then the outcome is "3". The management response for Clam Bay would
be determined based on the outcomes assigned to both the TN and TP evaluations for the
magnitude and duration of exceedance (Figure 2).
The water quality status of Clam Bay would be assigned a green, yellow, or red designation
annually based on the magnitude and duration of exceedances of the 90th percent prediction
limit. The color designation is then used to determine what level(s) of management actions are
appropriate.
Annual management response actions are based on the response to nutrient concentrations of
phytoplankton and dissolved oxygen (DO) as well as impacts on water clarity (Figure 3). If the
outcome of the TN and TP evaluation is green, then no management actions are required.
However, if the outcomes are yellow or red then further evaluation of the effect of elevated
nutrient concentrations on both phytoplankton biomass and DO concentrations need to be
reviewed. If there is no relationship between nutrients and chlorophyll-a or DO, then no
management actions are required. If there is a signification relationship, then the impact of
chlorophyll-a on the water clarity (Secchi disk depth) would be evaluated. If there is no
relationship between chlorophyll-a and water clarity, then no management actions are required.
If there is a significant relationship between chlorophyll-a concentrations and water clarity, an
outcome designation of "yellow" (indicative of small magnitude or duration of exceedances)
identifies that management actions should be taken to identify the potential causes and
responses for the elevated nutrient levels. It the outcome designation is "red" (indicative of a
large magnitude or duration of exceedances), management actions should be taken to
implement recommended response tactics to reduce nutrient concentrations. In this manner, the
"health" of Clam Bay is to be assessed annually.
Do 213%of all TN&/orTP
values from a calendar year
N a exceed the 90%prediction limit
from the reference WBID?
Outcome0 Yes
>13% Magnitude of >15%
exceedance
Duration of Duration of
exceedance exceedance
1 year >l year 1 year >1 year
Outcome 1 Outcome 2 Outcome 2 Outcome 3
Figure 1. Clam Bay water quality flow chart.
Agenda item#5b
Page 3 of 7
Total Phosphorus
Total Nitrogen Outcome 0 Outcome 1 Outcome 2 Outcome 3
Outcome 0
Outcome 1
Outcome 2
Outcome 3
Figure 2. Management response matrix using outcomes from both TN and TP
evaluation.
c,r een Response Yellow or Red
evaluation
Hold the
line
Evaluate phytoplankton/ Significant
dissolved oxygen (p<0.05)
Not significant response to nutrient
(p?0.05) concentrations
Evaluate water clarity
Not significant response to chlorophyll-a
(p',0.05)
Significant(p< .05)
Small difference or
short duration
Identify potential causes
and implement Identify potential
recommended response Large difference or causes and
long duration responses
Figure 3. Management response actions in response to various outcomes.
Agenda item#5b
Page 4 of 7
Data Analysis
The analysis conducted below was used to assess the water quality status of Clam Bay during
the months of February 2019 to July 2019. Since, the SSAC developed for Clam Bay is to be
evaluated on an annual time step, this analysis provides insight into current water quality
conditions within the Bay, but it does not substitute for the more comprehensive annual
assessment required. Clam Bay surface water quality data were provided by Turrell, Hall and
Associates, Inc. for comparison with the FDEP adopted SSAC established for Clam Bay and
found within FAC. 62-302-532 -1-j. The NNC SSAC states the following;
"No more than 10 percent of the individual Total Phosphorus
(TP) or Total Nitrogen (TN) measurements shall exceed the
respective TP Upper Limit or TN Upper Limit."
The TP and TN upper limits are calculated using equations 1 and 2:
Equation 1: TP Upper Limit (mg/L)= e(-1.oe25e-o.0000328465*Conductivity(Ns))
Equation 2: TN Upper Limit (mg/L)= 2.3601 — 0.0000268325*Conductivity(pS)
The dataset was supplemented with in situ water quality data (e.g., temperature, dissolved
oxygen, pH, conductivity, and salinity) retrieved from the chain of custody forms for each
sampling event. The corresponding TN or TP Upper Limit was calculated for each Clam Bay
estuarine water quality station and sampling date in which conductivity was available using
Equations 1 and 2. TN and TP concentrations were compared to the derived upper limit
thresholds to ascertain if elevated concentrations were identified (Appendix A).
Results
The period of time covered in this memo is from February 2019 to July 2019 which
encompasses two quarterly periods (Quarter 2 and Quarter 3). Additional data, from
November 2018 to January 2019, are included here as well. During the time period of
February 2019 to July 2019, there were six TN measurement from the open waters of Clam
Bay) which exceeded their Upper Limits for NNC criteria. In the prior annual report, a total of
fifteen (15) ambient water quality values for TN exceeded the respective TN Upper Limit. In the
prior quarterly report, there were three exceedances of the TN Upper Limit. These results
suggest that at least in terms of nitrogen, it does not appear that the open waters of Clam Bay
are overly problematic, as their frequency of exceeding the TN criteria is lower than during the
last annual report.
In contrast, 42 of the 54 TP measurements (78 percent) from the open waters of Clam Bay
exceeded their respective Upper Limits. This frequency of occurrence exceeds the 13 percent
threshold shown in Figure 1, which means that for this time period the open waters of Clam
Bay continue to have phosphorus concentrations that exceed the established criteria. The
exceedances occurred throughout all areas of Clam Bay and all sampling events. In the prior
annual report, 67 of 108 samples exceeded NNC criteria for TP, which indicates that elevated
TP concentrations have been prevalent for an extended period of time. Based on the results
Agenda item#5b
Page 5 of 7
from this time period, and if the frequency of exceedance seen here was to be maintained over
the course of a calendar year, Clam Bay would likely be determined to be impaired for TP.
The TN and TP exceedances are illustrated in Tables 1 and 2. The TP exceedances during the
second and third quarter are numerous, and are consistent with the widespread elevated
concentrations noted in the 2018 annual report. Since July 2018, TP concentrations have
been elevated throughout the entire Clam Bay system. This widespread pattern of
exceedances had been previously suggested to be related to tree defoliation and excessive
rainfall and runoff associated with Hurricane Irma. For example, after Hurricane Charley hit
Southwest Florida in 2004, widespread defoliation of vegetation brought about impacts to
water quality throughout both Charlotte Harbor and the Peace River watershed (Tomasko et al.
2006). However, the persistence of TP exceedances more than a year after the passage of
Hurricane Irma is not consistent with the shorter-term impacts that were recorded after the
passage of Hurricane Charley (Tomasko et al. 2006).
Table 1. Observed TN Exceedances (marked with an "X") at the ambient Clam Bay
surface water sample sites over the period of November 2018 to July 2019. "-" indicates
sampling dates without corresponding conductivity data. Boxes with neither an X or a
dash are in compliance with existing criteria.
Sampling event
Station Nov Dec Jan Feb Mar Apr May Jun Jul
1
2
3 X
4
5 X
6 X X
7 X X
8 X
9 X X
Agenda item#5b
Page 6 of 7
Table 2. Observed TP Exceedances (marked with an "X") at the ambient Clam Bay
surface water sample sites over the period of November 2018 to July 2019. "-" indicates
sampling dates without corresponding conductivity data. Boxes with neither an X or a
dash are in compliance with existing criteria.
Sampling event
Station Nov Dec Jan Feb Mar Apr May Jun Jul
1 X X X X X X X
2 X X X X X X X X
3 X X X X X X X
4 X X X X X X X X
5 X X X X X X X
6 X X X X X X X
7 X X X X X X X X
8 X X X X X X X X
9 X X X X X X X X
In addition, water quality data from six of the Clam Bay Outfall monitoring stations were
compared to the proposed downstream protective values (DPV) for Clam Bay (PBS&J 2011).
Outfall TN and TP concentrations were compared to the median and 90th percentile DPV
values to determine if elevated concentrations were identified (Appendix B).
The median and 90th percentile DPVs for TN are 1.31 and 1.80 mg/L, respectively (PBS&J
2011). The median and 90th percentile DPVs for TP are 0.10 and 0.25 mg/L, respectively. For
TN, 61 and 15 percent of the values exceeded the median and 90th percentile DPV criteria,
respectively, during the months of February 2019 through July 2019 (Table 3). It should be
noted that a "median" value represents a value where 50 percent of samples would be
expected to be in exceedance. Similarly, it would be expected by chance alone that 10
percent of values would exceed the 90th percentile DPV, vs. the 15 percent of TN values found
here. For nitrogen, the findings reported here are not far out of line for expectations set out in
the "hold the line" approach used to develop NNC criteria for Clam Bay. In contrast, while only
64 percent of TP values exceeded the median DPV criterion (which is expected to be
exceeded 50 percent of the time), 30 percent of values exceeded the 90th percentile DPV
criterion, which is expected to be exceeded only 10 percent of the time.
Table 3. Percentage of TN or TP concentrations from outfall stations which exceeded
the median or 90th percentile DPV values for stormwater runoff.
DPV Total Nitrogen Total Phosphorus
Median 90th Percentile Median 90th Percentile
Percent of values below 39 85 36 70
Percent of values above 61 15 64 30
Agenda item#5b
Page 7 of 7
Discussion
It should be noted that because this data analysis is not based on a full calendar year of data,
it is only an indicator of the potential for the Clam Bay system to be determined to be out of
compliance with its established water quality criteria (FAC 62-302.531). However, quarterly
status reports can be useful as an early warning system to alert the County of situations where
water quality might be significantly out of compliance with established criteria.
As was previously noted in the 2018 Annual Report, the findings displayed here suggest
phosphorus concentrations in the open waters of Clam Bay are potentially problematic. Within
the Quarters 2 and 3 of 2019, 78 percent of TP values exceeded a threshold value meant to
"hold the line" on nutrient concentrations in the Clam Bay system. Additionally, elevated
nutrient concentrations at outfall sampling locations identified that during this quarter, 30
percent of TP values from sampled outfall locations exceeded a criterion that is expected to be
exceeded 10 percent of the time. These results suggest that the watershed may be
contributing elevated concentrations of TP in runoff to Clam Bay. These findings suggest that
elevated TP concentrations in Clam Bay could be due to activities in the watershed, as well as
from "internal" sources such as mangrove decomposition and/or roosting birds.
In contrast to previous reporting periods, concentrations of nitrogen are slightly elevated at the
outfall locations, as exceedance rates for the median DPV concentration are greater than what
is to be expected. Despite the elevated TN concentrations in the outfalls, a concurrent impact
on nitrogen in Clam Bay was not observed.
Taken as a whole, the water quality data collected between the months of February 2019 and
July of 2019 suggest that the open waters of Clam Bay have more phosphorus than would be
expected, as 78 percent of samples exceeded the criteria spelled out for Clam Bay in the State
of Florida's Impaired Waters Rule (FAC 62-302.531). For nitrogen, no such concern currently
exists.
3/4/2020 ClamPass-TIDE I humistonandmoore Agenda item#6a
Page 1 of 2
" opesforirl 6ecclies as Nattwal Coastal Systems "
7 HUMISTON & MOORE
ENGINEERS
Consulting Coastal Engineers Home About H&M Services Projects Contact Careers Client Login t.
I I
CLam Pass Tide Monitoring - Click here for Maintenance Dredging Project details
Goryof Mexico i
MARKER 4 MARKER 14 MARKER 26 MARKER 32 " „''`5
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ide Gages Location,,;3l A..4:,4•9A4 .•; ..C...,^.. 'Z.4.s�' ► L'446r1li+ . .: ..,,., 4 ,',y ..,'4ot,
Monthly Time Series 2020(Click on Thumbnails to Expand)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mean Low TideTime Lag -2020
250.0 -
r
2.00.0 •
C
2 150.0 . ■Marker 4
o. Marker 14
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33
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9 50.0 - 'Gage nut
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properly
0.0 • r r .
Ian Feb Mar Apr May Jun Jot Aug Sep Oct Nov Dec
Gage/Gulf Mean Tide Ratios -2020
0.90
0.80 •GaEe not
working
0,70 ,
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2 0.30 • a Marker 32
0.20 - • c�arr.o
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0.10 Rito
WV re.
Jan Feb Mar Apr May Jun Jul Aug Sen Oct Nov Dec 41i 14.
Gage/Gulf Mean Tide Ratios -2019
https://www.humistonandmoore.com/clampass-tide 1/3
3/4/2020 ClamPass-TIDE(humistonandmoore Agenda item#6a
Page 2 of 2
" Restorindc (eaclzes as /natural Coastal csstelns
HUMISTON & MOORE
1
1
Consulting CoaE1ERS
stal Engineers Home About H&M Services Projects Contact Careers Client Login
78 v." i i Ij I i II Il I 1 III II I Ii I . I . ',Macke!14
Gage/Gulf Mean Tide Ratios -2018
• 0,90
i uiitue
rz
11.* l
0.80 'Gap not
0,70 . kNilii, 11-, 11 , 11 , 1 .
working
' I i RruJisrly
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co 0.50
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l' 0.40 - 1I ■Marker 26
0.30o Marker 32
ry
0.20 • • ck rat0.10 1 ` , 11 .111 . l ... „ L.
OAO hta,kas
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 4 R L8.
Gage/Gulf Mean Tide Ratios -2017
0.9 r Aetsgr n..1c., c rma
0.6 Tror2.7 5:nr,'
0.7 Em:y 1
c0,5 I- iiMasker.
m
Ll Marker tri
P- 0.4
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0.2 � 0,8,41
0.0 I .ii I li 1 1, li Pang.,le.
!.takes
len Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 4814.
Gage/Gulf Mean Tide Ratios -2016
0.9
PASS T.S.
01 DREDGING 1.5.COLIN t1ERMINE
0.7 , 1
1
0.0 �:, I 1 .;
ti'cc ■Marker 4
0,5 741 I l Marker 14
0.4
en Marker 26
2 0,311.1 .111111.1 li 111111.1 11.1 lilt] IL 1111 n Marker 32
0.2 •
0.1
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 481°'
Definitions:
Mean Tide Ratio:ratio of tide amplitude of gages over the tide amplitude from the Gulf of Mexico,averaged over a month.This
ratio is representative of the pass's effectiveness in flushing water from the bay. The lower the ratio, the less efficient is
Flushing,indicating material accumualting in the pass.
Wean Low Tide Lag: time difference between low tide in the Gulf of Mexico and at the gage's locations, averaged over a
month in minutes.The time lag is also represenattive of the pass's effectiveness in flushing water from the bay.The higher the
lag the less efficient is flushing,indicating material accumulating in the pass.
https://www.humistonandmoore.com/clampass-tide 2/3
Identify Need
Timeline to Dredge Clam Pass AgenPaa9ee;of#6'
to Dredge (Non—Emergency)
(NRPA or 30 _30 to 60
schedule) 30 30 to 60 I
Contractor
Issue Task Prepare Plans and Procurement Selection and
Order for Specifications for Issues Request Contract
' "",.:.rest Design,BCC& g Procurement for Bids Preparation
PBSD Bathymetric
Approve Survey for
Project Design/Pay
Quantities
Regulatory Notice BCC& TDC
to Proceed & Pre- PBSD
Construction Approve Approves
Funds
Meetings ontrac
IIIIIIII
LTotal Time to Construction:180 to 210 days Mobilization,
Construction &
,Co„ tic, Time(Mob to Demob):60 to 90 days Demobilization
Agenda item#6c-1
Page 1 of 5
2018 Dredging
March 8 Clam Bay Committee meeting minutes
• Bathymetric survey had been completed.
• No decision on whether dredging was needed had been made.
March 26 Special PBSD Board meeting minutes
• Neil reported that approvals from PBF Board and Tourist Development Council had been
granted.
• Neil reported that BCC approval would be requested at meeting on March 27.
April 4 PBSD Board meeting minutes
• Neil reported that dredging should be underway about April 15.
May 3 PBSD Board meeting minutes
• Neil reported that dredging may be substantially complete by May 8.
Agenda item#6c-1
Page 2 of 5
Pelican Bay Services Division Clam Bay Committee Meeting
March 8,2018
• Obtain drone photos of nesting bird colonies in Upper Clam Bay which may be
contributing to high phosphorus levels.
• Continue with CH2M l lill water quality reports.
• Mr. 1-lall will prepare a proposal for selective sediment testing in Upper Clam Bay, in
order to determine whether high copper levels are basin 4 sourced.
• Mr. Sterk's sediment testing results from last year will be reviewed for comparison to
this year's results.
COPPER RESULTS FOR NOV.2017
Ms.O'Brien commented that the November 2017 copper results looked good.
UPDATE ON WIN ENTRY
Ms. Jacob will contact the Collier County lab to determine when the lab expects to begin
WIN entry for Clam Bay data.
CLAM PASS
FEBRUARY TIDAL RATIO REPORT
Dr. Mohamed Dabees, consultant with Ilumiston & Moore, commented that the January
and February 2018 tidal ratios are below the critical threshold, which has triggered a bathymetric
survey to be completed.
TIMELINE FOR DREDGING-RELATED ACTIVITIES
Dr. Dabees commented on the potential for a Clam Pass dredging project within the next
few months and highlighted the following:
• The Clam Bay Management Plan protocols are being followed.
• A bathymetric survey of sections A,B, &C has been completed.
• The quantities of sand identified in the bathymetric survey will determine the need for a
dredging project;exceeding a specified sand threshold is required to justify a project.
• A decision to dredge will immediately be shared with Mr. Don-ill, the PBSD hoard, and
- the County.
• A dredge decision will trigger a shore bird survey to be completed by Mr. Sterk and the
preparation of dredge construction plans to he completed by Dr. Dabees.
Ms. O'Brien requested that Mr. l)orrill provide the PBSD board with a timely decision
update and the timing of when construction plans will he available for hoard approval.
CLAM BAY
UPDATE ON DEBRIS REMOVAL/HAND-DUG CHANNEL MAIN'T'ENANCE
Ms. Jacob commented that the PBSD is planning to determine from FEMA which areas
of Clam Bay, including the berm, hand-dug channels, and the waterways will be eligible for
FEMA reimbursement for debris removal. Based on this determination, the PBSD, with the
assistance of our FEMA consultant, will hid out the entire debris removal project. The debris
removal and maintenance of the hand-dug channels will be completed at the sante time.
CANOE TRAIL MARKER 12
3
Agenda item#6c-1
Page 3 of 5
Pelican Bay Services Division Board Special Session
March 26,2018
Dr.Joseph Doyle commented on(I)his support ot'the dredging project,(2)questioned the
total dollars spent on dredging Clam Pass from 1998-2018,and (3) the lack of backup material in
the agenda packet for the March 7 P1351) Board meeting relating to the transfer of$1 million
dollars between two PUSI) funds.
Ms. Vanessa I3ooher, Conservancy of SW Florida, spoke on behalf of Ms. Kathy Worley
(Conservancy of SW Florida) and asked, "What are the dredge triggers?" and "Are there any
permit diferences for this dredge as compared to the 2016 dredge?"
RE,VII W t)F'1'IU CLAM PASS CONSTRUCTION PLANS AND SPECIFICATIONS
Mr. Dorrill commented that he has obtained the approval of the plans for an emergency
maintenance dredge by the P13F Board and the 'Tourist Development Council, He is requesting
approval of the dredging/construction plans by the P1351)Board to move forward on an emergency
basis,using an expedited procurement process in order to get the project underway before sea turtle
nesting season, The plan includes using a hydraulic dredge with options for mechanical work.
Mr. Dorrill commented on the three dredge triggers as described in the Clam Bay NRPA
Management Plan: (1) tidal range rutins falling below 'A foot,(2) results of a bathymetrie survey,
which show 8000-8200 cubic yards of material in sections A,i3,and C, and(3)the misalignment
of the inlet meeting the Gulf of Mexico.
Mr, I)orrill commented that an executive summary is on the 3/27/2018 Board of County
Commissioners agenda(tomorrow),requesting approval for an emergency maintenance dredging
ffopect, using i 1)C Funding, Sand from the dredging project will be placed south of Clam Pass,
in front of the concession/pavilion Kea.
Mr, Dave Cook commented on a parallel channel to Clam Pass (on the south side). Mr,
Dorrill commented that the material in this cluumel is not beach compatible.
Dr. Joseph Doyle suggested that the PBS!) Board obtain another opinion on possible
alternative methods of managing Clam Pass(in light o13 dredging projects in 3 years). Mr.Dorrill
commented that it may be appropriate to re-evaluate the management plan.
Ms, Linda Roth commented that other Collier County passes with jetties such as Doctors
Pass,Wiggins Pass,and the Marco Island Pass all require dredging every two years,
1)r. Mohamed 1)abees commented that the Clam Bay NRPA Management Plan xvas
developed over many meetings with participation by all of the stakeholders,
• Mr. Strcckenbein commented that Clam Pass is there for the protection of the environment.
Mr. llirniak motioned,Mr.Cravens seconded to approve the construction planus
as aresentetl. The motion carried utaanimonsiv.
AWOL/RNMENT
�The mcetua, was aad'out used at 1:30 nu.
Scott Streckenhein, Chairman
Minutes approved[a ')as presented OR [ l as amended()N 1_,.L-L21:11,_.. ----]dote
2
Agenda item#6c-1
Page 4 of 5
Pelican Bay Services Division Board Regular Session
April 4,2018
commented that we are pursuing FEMA mitigation funds for a redesign (new specifications) of
the damaged signs, which would result in installing signs which are more hurricane resistant. If
we are not successful in obtaining these additional mitigation funds, then the PBSD would be
responsible for the supplemental costs. Ms. O'Brien suggested that the PBSI)consider a"multi-
year project" if the mitigation funds are not approved, in order to spread the supplemental costs
over a number of years.
Mr.Dorrill will share the bids received for each project with board members when they are
received,and will bring the projects to the board as an agenda item for discussion, if time permits.
UPDATE ON TIMELINE FOR 41 BERM CLEAN-UP AND RESTORATION
Mr. Dorrill reported that tree removal on the US 41 berm is in its final phase. As a result
of Hurricane Irma, a total of 65 large trees were lost and the berm was substantially damaged in
22 locations. Our engineer ABB has provided us with a survey,overlaid on an aerial photo of the
entire area. Mr. Dorrill commented that our landscape architect, Ms. Ellin Goetz (of Goetz &
Stropes Landscape) is working on suggested plantings with appropriate sizes, and hopefully
concept drawings can be reviewed at the next PBSD Board meeting. Mr.Dorrill will obtain a copy
of the original landscape plans of the US 41 berm for review. Mr. Dorrill will invite Ms. Goetz to
attend the next Landscape&Safety Committee meeting.
Mr. Cravens suggested that all plans be reviewed to ensure that no exotic invasive plants
arc replanted.
UPDATE ON TIMELINE AND COSTS FOR DREDGING CLAM PASS
Mr.I)orril I reported that on Monday he authorized a one-week extension to the bid deadline
(for the Clam Pass dredging project)until April 10,as a result of contractors requesting additional
time to prepare their bids. He will share the bids with board members when they are received.
After-the-fact approval of the bid selection will be obtained from the Board of County
Commissioners. Mr. Dorrill projects the project will be underway on or about April 15. Mr.
Dorrill commented that there arc fluids in the project's budget for enhanced security at the project
site.
Ms. O'Brien commented on the proposal for engineering services by Humiston&Moore
for$68,000,which is significantly higher than last year's proposal of approximately$40,000.
UPDATE ON DRAINAGE EASEMENTS AND DEBRIS REMOVAL
Mr. Dorrill commented on the following debris removal projects in P1351) drainage
casements. None of these projects are FEMA eligible.
• Bids are out and expected hack next week for debris removal and maintenance to
restore flow to PBSi)'s Ritz Carlton drainage easement.
• Bids are out and expected hack next week for debris removal and maintenance to
restore flow to PBSL)'s beach dune swale drainage easement.
• Once the beach dune swale project is complete,a new project is anticipated for the
engineering and construction of three additional sump areas for water retention
behind several Bay Colony condominiums.
• A title search has been completed at the Grosvenor to identify PBSI) drainage
easements. Quotes are currently being obtained to complete debris removal and
maintenance work in our drainage casements in this area, and once this work is
complete, our engineer will be tasked to provide a solution to restore proper
drainage.
3
Agenda item#6c-1
Page 5 of 5
Pelican Bay Services Division Clam Bay Committee Meeting
May 3,2018
CANOE TRAIL MARKER 12
Mr. Sterk commented that canoe trail marker 12 remains on the County's list of markers
to be replaced.
UPGRADE MODEMS ON TIDAL GAUGES (ADD-ON)
Ms.Jacob commented that she will work with Mr. Sterk and/or Mr.Kevin Locher(Locher
Environmental) to upgrade the modems on the tidal gauges, at a maximum estimated cost of
$2,000. The deadline to upgrade is December 2019.
CLAM PASS
UPDATE ON DREDGING
Mr.Dorrill provided an update on the current dredging project,which may be substantially
complete by Tuesday,May 8. He commented very positively on the quality and speed of the work
of the contractor,Cavache,Inc.
II&M APRIL TIDAL RATIO RESULTS
Ms.O'Brien commented that the April tidal ratios look good. Mr. Dorrill commented that
Dr. Dabccs reported to him that this morning's tidal ratios were.76 or.78 which were the highest
he has ever seen.
FDEP REQUIRING IDLE SPEED SIGNAGE
Ms.O'Brien commented on an e-mail from Mr.Dave Cook to Mr.Don-ill,which suggested
that a condition of the FDEP Clam Bay permit requires that there be idle speed and no wake
signage in Clam Bay. Mr. Dorrill commented that he will discuss this issue with Dr. Dabees.
WATER QUALITY
PROPOSAL FOR COPPER SEDIMENT TES'T'ING IN UPPER CLAM BAY
Ms.O'Brien commented on the Turrell,I Tall&Assoc.sediment testing proposal of$2,962
to help determine the source of high copper at Station#9(as provided in the agenda packet).
Mr. Ilirniak motioned, Ms. O'Brien seconded to approve the Turrell, Hall &
Assoc.sediment testing proposal of$2,962. The motion carried unanimously.
COPPER RESULTS
Ms. O'Brien commented that November 2017—January 2018 copper results look good.
UPLAND POND WQ REPORTS
Ms.O'Brien commented that on 4/16118 the Water Management Committee suggested that
the Clam Bay Committee take another look at the possibility of reducing the proposed expenditure
of$25,000 for four CH2MIIi1I quarterly water quality reports on WQ data from 28 of the upland
ponds we manage.
Mr. Shepherd questioned what is actionable as a consequence of gathering this data.
Ms. O'Brien commented that we are currently impaired for copper and not meeting the
criteria for total phosphorus in Clam Bay. She suggested that the FDEP may ask,"What are your
inputs from the upland ponds into Clam Bay?" Ms. O'Brien commented that the water quality
data is collected for documentation purposes and to provide to the FDEP as a defense and/or
response to an inquiry. Mr. 1'hrniak commented that this documentation would show that we are
3
Agenda item#9
Page 1 of 1
DRAFT
FY 21 Clam Bay Budget
Current contracts and estimated costs
$70,750' ETE Clam Bay monitoring and annual report
32,0002 THA Water quality monitoring and quarterly and annual reports
9,000 H&M Monthly tidal analysis reports and aerial photos of Clam Pass
10,000 H&M Annual bathymetric &tidal analysis report
6,500 H&M Annual bathymetric survey
18,500 County Lab Water quality sample collection, and analysis, and WIN entry
30,000 ? Hand-dug channel maintenance
31,000 ? Exotic treatment
? ? Scaevola treatment
2,000 Verizon Transmittal of data from tidal gauges
800 Locher Web hosting for tidal gauges
TBD Reserves for contingencies
TBD Tax collector fees
TBD Property appraiser fees
? Equipment repairs
? Other
n.b. $150,000 available in County's 111 Fund
FY19 fund balance will be available about March 31, 2020
FY20 fund balance needs to be estimated before FY21 assessment is established
1 Includes $12,000 for T&M
2 Includes $8200 for T&M