The priority projects for Lake Tarpon focus
on preservation and improvement of existing water quality. Projects are included to monitor the effects
of the management strategies and to provide information to be used by lake
managers to refine the nutrient budget for the lake. The following project summaries describe the projects and provide
a project timeline and estimated budget.
Project Title: Stormwater Rehabilitation
Summary:
This project involves the construction of
enhanced stormwater treatment facilities at the outfall of the priority
manageable hydrologic units (MHUs) and individual sub-basins identified in the
Lake Tarpon Drainage Basin Management Plan (PBS&J 1998). Based on modeled pollutant loading
estimates, the MHUs and sub-basins are shown below in the order of decreasing
priority. The locations of these MHUs
and sub-basins are shown in Appendix A.
·
Group B MHUs (contributing
sub-basins 49,51,52 and 54)
·
Group D MHUs
(contributing sub-basins 5 and 6)
·
Group A MHUs
(contributing sub-basins 60, 62, 63, 65 and 66)
·
Group C MHUs
(contributing sub-basins 45, 46 and 47)
·
Individual
sub-basin 23
·
Individual
sub-basin 21
Given the potentially high cost and low
availability of land for development of these enhanced stormwater treatment
facilities, the use of more intensive treatment systems such as alum injection
with floc settling ponds represent a more cost effective approach per unit area
of land. Therefore, alum injection
facilities with floc settling ponds are the recommended technology.
Annual Budget Estimates:
|
|
FY 2000 |
FY 2001 |
FY 2002 |
FY 2003 |
FY 2004 |
|
Salaries |
|
|
$15,000 |
$15,000 |
$15,000 |
|
Contracts |
|
|
$450,000 |
$450,000 |
$450,000 |
|
Expenses |
|
|
$1,200 |
$1,200 |
$1,200 |
|
Total |
|
|
$466,200 |
$466,200 |
$466,200 |
Agency or Local Government Partnering:
Pinellas County, through the development of
the Lake Tarpon Drainage Basin Management Plan, identified the priority MHUs
and individual sub-basins that were feasible for stormwater retrofit
projects. The District through the
cooperative funding program of the Pinellas-Anclote River Basin Board and
through SWIM funding can join with Pinellas County to share the costs of
construction.
Project Title:
Feasibility and Conceptual Design Study for a Stormwater Treatment
Facility at John Chesnut, Sr. Park
Summary:
The Stormwater Rehabilitation project
described previously, identifies four manageable hydrologic units (MHUs) and
two individual sub-basins as possible sites for implementation of stormwater
retrofit projects. Of the MHUs and
sub-basins, Group C was identified as contributing the fourth highest pollutant
load to the lake, which equates to 0.85 tons per year of TN and 0.08 tons per
year of TP. A portion of this runoff
flows into a canoe trail in the John Chesnut, Sr. Park, and then into wetlands
which discharge to Lake Tarpon. The
ponds that form the canoe trail have experienced algal blooms that inhibit
recreational and aesthetic uses.
This project proposes to determine the
feasibility of designing, permitting and constructing a treatment system for
Group C that will hydrologically connect to the existing ponds. The feasibility and conceptual design report
will contain a cost-benefit analysis if the project were to be constructed.
Annual Budget Estimates:
|
|
FY 2000 |
FY 2001 |
FY 2002 |
FY 2003 |
FY 2004 |
|
Salaries |
$2500 |
|
$2500 |
|
|
|
Contracts |
$45,000 |
|
$600,000 |
|
|
|
Expenses |
$500 |
|
$500 |
|
|
|
Total |
$45,500 |
|
$600,300 |
|
|
Agency or Local Government Partnering:
Pinellas County submitted this project for
cooperative funding during the FY 2000 funding cycle. The project has been approved for funding and an agreement with
the County has been executed.
Project Title: Fisheries Monitoring
Summary:
Lake Tarpon historically has supported a
healthy, well balanced fish population.
Recent increases in fish biomass have concerned lake managers since this
may be indicative of increasing eutrophication (productivity) of the lake. Monitoring of the fish community structure
and fish biomass are necessary to document changes in these conditions as a
result of management strategies implemented to decrease lake productivity.
Annual Budget Estimates:
|
|
FY 2000 |
FY 2001 |
FY2002 |
FY 2003 |
FY 2004 |
|
Salaries |
$5,000 |
$5,000 |
$5,000 |
$2,000 |
|
|
Contracts |
$41,800 |
$23,300 |
$23,300 |
$7,000 |
|
|
Expenses |
$1,000 |
$1,000 |
$1,000 |
$1,000 |
|
|
Total |
$46,900 |
$29,300 |
$29,300 |
$10,000 |
|
Agency or Local Government Partnering:
Pinellas County has entered into a multi-year
agreement with the University of Florida to conduct baseline fisheries studies
on the lake and to evaluate responses to implemented management
strategies. The County is paying for
the total cost of the first year of the study and the have submitted a
cooperative funding request to fund the remaining 4 years. This funding request has been approved and
an agreement between the County and District has been executed.
Project Title: Refinement of Stage and Flow Measurements at
the Lake Tarpon Outfall Structure
Summary:
The Lake Tarpon Outfall Canal provides a convenient structure for measuring flow and collecting water samples; however, instrumentation for accurately measuring and recording stage and flow volumes does not exist at the outfall control structure. The installation of state-of-art instrumentation is needed to address the defined monitoring objective of calculating annual water and nutrient budgets for Lake Tarpon. The estimation of mean annual TN, TP, and hydrologic loads discharged from the lake combined with estimates of mean annual loads entering the lake are needed to calculate lake water and nutrient budgets. To balance a water/nutrient budget, direct measurement of outflows from the lake are needed. Annual estimates of loads leaving the lake will enable the calculation of net loadings into the lake, loads which should be related to mean annual chlorophyll-a concentrations and TSI values.
Annual Budget Estimates:
|
|
FY 2000 |
FY 2001 |
FY 2002 |
FY 2003 |
FY 004 |
|
Salaries |
$5,000 |
$5,000 |
$5,000 |
|
|
|
Contracts |
$40,000 |
|
|
|
|
|
Expenses |
$2,000 |
$2,000 |
$2,000 |
|
|
|
Total |
$47,000 |
$7,000 |
$7,000 |
|
|
Agency or Local Government Partnering:
The District would be the lead agency to
implement instrumentation and collection of data and funds are included in the District’s
FY 2000 budget to begin this project.
Project Title: Enhanced Lake Level Fluctuation
Summary:
This project involves modifying the operational
schedule of the Lake Tarpon Outfall Canal control structure (S-551) so as to
provide for greater intra-annual lake level fluctuation, and inter-annual
variability. An enhanced lake level
fluctuation schedule is not meant to be implemented rigidly, but rather it is
to serve as a guideline for improved lake management. The design and capabilities of the Lake Tarpon Outfall Canal and
control structure (S-551) allow for maximum flexibility in the management of
lake levels. To date, the outfall structure
has been rather conservatively managed solely for the purpose of flood control.
It is difficult to quantify the water
quality benefits of periodic lake flushing because of the complex biological,
hydrogeological and chemical interactions.
There is, however, empirical evidence that short-term lake drawdowns in
Lake Tarpon can have significant positive impacts on water quality. An accidental short term lake drawdown which
occurred in March 1990 appears to have resulted in the reduction of in-lake chlorophyll-a
concentrations for the remainder of that year. More information is found in Appendix A.
Annual Budget Estimates:
|
|
FY 2000 |
FY 2001 |
FY 2002 |
FY 2003 |
FY 2004 |
|
Salaries |
$5,000 |
$5,000 |
$5,000 |
|
|
|
Contracts |
|
|
|
|
|
|
Expenses |
$2,000 |
$2,000 |
$2,000 |
|
|
|
Total |
$7,000 |
$7,000 |
$7,000 |
|
|
Agency or Local Government Partnering:
The U.S. Army Corps of Engineers must approve
any major deviations from the existing operational range and schedule for
structure S-551. The District has the
responsibility for operation and maintenance of structure S-551, and would be
responsible for operating the structure to attempt to achieve the target
monthly lake levels. Pinellas County
would be responsible for hydrobiological monitoring to document the impacts of
implementing the enhanced lake level fluctuation schedule and for initiating
public meetings to educate the public about the benefits of greater lake level
fluctuation.