In September of 1994, Pinellas County entered into an agreement with Coastal Environmental, Inc. (subsequently purchased by PBS&J, Inc. in 1996) to prepare the Lake Tarpon Drainage Basin Management Plan (the Plan). Building upon the work of the diagnostic/feasibility study, the Plan is to be composed of management policies and best management practices - both structural and non-structural - aimed at restoring and/or maintaining the hydrological and ecological integrity of the lake and its immediate watershed. As such, the Plan should specifically include recommended management options and BMPs addressing priority lake and watershed management issues identified by the Lake Tarpon Management Committee (LTMC).

This document - The Lake Tarpon Drainage Basin Management Plan - represents the culmination of a decade of resource planning activity undertaken by numerous governmental agencies and key individuals. The management actions recommended herein are based on the extensive knowledge gained from the scientific/engineering studies and monitoring programs conducted to date, and represent the most cost-effective means of attaining the adopted goals of the LTMC.

The primary purpose of the Lake Tarpon Drainage Basin Management Plan is to provide implementation guidance for the Pinellas County Growth Management Plan with respect to lake, wetland, and upland management issues in the Lake Tarpon basin. As such, the Plan is to provide specific recommended management options addressing the following management objectives:

• reduce pollutant and nutrient loadings from both internal and external sources;

• improve lake water quality (e.g. reduce TSI; meet applicable state water quality standards);

• control nuisance and exotic aquatic vegetation;

• increase the quality and diversity of in-lake and watershed natural habitats;

• sustain or enhance a balanced assemblage of endemic sport fisheries and wildlife;

• provide for public flood protection;

• maintain or enhance the aesthetic and recreational attributes of the lake;

• maximize and balance recreational opportunities for all user groups; and

• advance public knowledge and understanding of the lake ecosystem and its watershed.

Because concern over declining water quality was the original driving force behind the planning process, the primary focus of the Plan was the development and evaluation of various BMPs and other structural and non-structural remediative measures to reduce external and/or internal pollutant loadings to Lake Tarpon, while maintaining effective public flood protection. The reach of the Plan, however, extends well beyond water quality and flood control issues. Using the evolving "ecosystem management" approach, the Plan addresses the interactions between water quality and quantity, and dependent living resources such as fish, wildlife and natural habitats.

A total of seven priority lake and watershed management issues were identified by the LTMC. A brief summary of the problem statement associated with each priority issue is provided below.

Issue #1 - Water Quality: Excessive nutrients in surface waterbodies can lead to declining water quality and associated ecological degradation. The process of excessive nutrient enrichment is referred to as eutrophication. Available monitoring data indicate that water quality in Lake Tarpon, as measured by chlorophyll-a and nutrient concentrations, is declining. There is a justifiable concern that eutrophication is advancing to a level where other adverse ecological changes could soon follow. Conversely, no significant public health related water quality problems, such as high concentrations of toxics or pathogens, have been observed in Lake Tarpon.

Issue #2 - Aquatic Vegetation: Available assessment data indicate that the diversity of emergent aquatic vegetation has declined significantly in the last 25 years with the implementation of a water level control schedule, and the resulting proliferation of monotypic stands of cattails dominating the shoreline of the lake. Cattails obstruct waterfront views and shoreline access, and provide poorer fish and wildlife habitat than other more desirable vegetation. In addition, keeping the coverage of nuisance submerged aquatic vegetation such as hydrilla in check presents a continuous management challenge. Large scale chemical treatments of hydrilla in Lake Tarpon have been correlated with degraded water quality, probably due to the water column release of nutrients from the excessive plant tissue decomposition.

Issue #3 - Fisheries: Lake Tarpon is one of the foremost sport fishing lakes in Florida. The largemouth bass and panfish fisheries are considered to be healthy, however, more recent assessment data indicate that fish biomass in Lake Tarpon has increased substantially since 1992, indicating a trophic state shift. There is a justifiable concern that advancing eutrophication in Lake Tarpon could threaten the integrity of the sport fisheries.

Issue #4 - Wildlife and Associated Habitat: Land development in the Lake Tarpon watershed has resulted in the loss of hundreds of acres of natural habitats and their associated wildlife populations. Although existing wetlands in the basin are well protected under federal and state laws, measures to protect remaining upland habitats are needed. Furthermore, urban wildlife management programs and techniques such as golf course and residential habitat enhancement could improve wildlife utilization of the basin.

Issue #5 - Flood Control: The construction of the Lake Tarpon outfall canal and water level control structure in the 1970s effectively addressed the severe flooding problems that existed in the basin prior to these actions. The primary concern with regard to the flood control issue in the Lake Tarpon basin is that the level of flood protection currently provided by the outfall canal and structure not be significantly compromised to accommodate the attainment of other lake management goals.

Issue #6 - Recreation and Aesthetics: Lake Tarpon is an important economic resource to Pinellas County and the City of Tarpon Springs due to the recreational aesthetic benefits it provides. Recreational benefits include sport fishing, boating (including personal watercraft), water skiing, and more passive uses such as canoeing and bird watching. Lake user surveys indicate that a high proportion of recreational boaters and skiers are attracted from neighboring counties, whereas sport fishermen are attracted from all of Florida and neighboring states. These surveys also indicate that conflicts exist between certain user groups, primarily water skiers and fishermen, who often pursue incompatible recreational activities in the same areas at the same time. As a result, the quality of the recreation experience, and possibly public safety, has been compromised. In addition, the highly attractive aesthetic environment provided by the lake adds considerable value to waterfront and nearby residential properties. There is a justifiable concern that unresolved user conflicts and degrading ecological conditions could adversely impact the socioeconomic benefits provided by Lake Tarpon.

Issue #7 - Public Education: Residential surveys of people living in the Lake Tarpon basin indicate that the general population is generally not knowledgeable regarding lake and watershed management issues. However, these same surveys indicate that many residents are interested in helping to monitor and improve environmental conditions in the lake and watershed. A need exists to better inform the public of issues facing Lake Tarpon and to solicit public support and volunteerism in the implementation of the Plan.

In addressing the above listed management issues, the Plan presents the development and prioritization of a wide range of recommended management options in an integrated manner. In addition to the evaluation of structural BMPs in the watershed, and in-lake remediative measures, the Plan further addresses the project objectives through a variety of regulatory, management, and policy components. The Plan is broken down into the following nine primary components.

A total of 22 specific management actions or components are recommended in the Plan. They include the following:

In addition to the 22 components listed above, the Plan includes a comprehensive monitoring program to evaluate the long-term success of Plan implementation.

The cost of implementing the Plan over a 10-year period has been estimated at $19,380,000. It should, however, be noted that design plans and specification have not been prepared for the major structural components of the Plan, and market-driven unit costs can vary significantly due to many factors. Nonetheless, the estimate of the total cost to implement the Plan was prepared with the best information available to date. Estimated costs can be broken down as follows: