Technical reports

Agricultural water use for irrigated acreage in the St. Johns River Water Management District was projected for 1991 and 2010.

In this supplement to SJ92-SP1, agricultural water use for irrigated acreage in the St. Johns River Water Management District was projected for 1995 and 2010.

Golf course land and water use projections are needed in order to compare water needs (demands) and sources (supplies) in the St. Johns River Water Management District. Water use was estimated for the base year 1990 and projected for 1995 and 2010.

Experimental ponds were used to test the hypothesis that bighead carp, a filter-feeding fish, could improve water quality and reduce the excessive growth of nuisance algae in Lake Apopka.

The objective of this survey was to obtain information about the water quality in the Upper Floridan aquifer from the geoelectric sections measured.

The primary objective of this study was to develop an up-to-date groundwater flow and chloride transport model to be used for predictive purposes within the context of a water supply needs and sources assessment.

This report includes information on fish and wildlife species and their habitats in the Lake George Basin and impacts of development on these habitats; regulatory review; and a summary of recommendations.

This study was initiated to develop the capability of forecasting critical low groundwater levels in space and time using stochastic modeling techniques. These models, founded on the principles of probability theory, provide a systematic method for estimating and predicting water levels and recharge rates, which vary erratically in space and time.

This study was instituted because Lake Apopka contained high concentrations of phosphorus, and excessive algal (phytoplankton) growth was identified as the prime symptom of eutrophication in the lake. Studies on this shallow, hypereutrophic lake were conducted from December 1989 to November 1991.

Bathymetric surveys were conducted using a fully automated hydrographic system. Sediment thickness surveys were also positioned with the system, and sediment depths were obtained using a low-pressure water jet probe.

This study was conducted to assess the history of cultural eutrophication in Lake Weir, the causes for deterioration of water quality, and the current status of the lake, and to develop management recommendations to preserve water quality in the lake.

The purpose of this project was to identify the presence and areal extent of karst features in the strata below the selected lakes, all of which have experienced varying degrees of water level decreases over the past 10 to 15 years.

In 1986 and 1988, time domain electromagnetic (TDEM) measurements were made in Seminole County as part of formulating a 20-year water management plan for the county. Previous measurements were re-examined due to improvements in data acquisition and processing, particularly for stations located in urban (high noise) areas, and in the development of a better understanding for correlating the geoelectric sections derived from TDEM to water quality.

The purpose of this study was to use existing data to prepare a comprehensive water budget and nutrient budget for Lake Jesup to support an analysis of restoration feasibility and techniques for the lake.

As part of its needs and sources assessment effort, the St. Johns River Water Management District requested HydroGeoLogic to revise and expand on an existing groundwater flow model of east-central Florida, including Orange and Seminole counties and portions of Lake, Volusia, Brevard, and Osceola counties. The primary purpose was to assess the impacts of utilizing sources of fresh groundwater in Orange and Seminole counties, given the projected demand for the 20-year planning period.

The Upper Etonia Creek Basin, located in parts of Alachua, Bradford, Clay and Putnam counties, is part of the Lower St. Johns River Basin. In January 1990, the study evaluated long-term changes and trends in rainfall, evapotranspiration, groundwater levels, and water use in the basin. This second phase of the project consisted of compiling and evaluating hydrologic data, developing a groundwater model, simulating lake stages using water-budget data, and estimating the impacts on the stage of Lake Brooklyn that would be caused by drawdowns in the Upper Floridan aquifer and by changes in the surface water flow into Lake Brooklyn.

This report presents the results of the first phase of a three-phase study of the Wekiva River Basin. The overall objective was to provide the St. Johns River Water Management District with a tool to aid in the establishment of minimum groundwater levels within the basin to protect water quality.

A two-dimensional, cross-sectional groundwater flow and saltwater transport model of a portion of the Wekiva River Basin was developed to assess saltwater intrusion. This study is the second phase of a project designed to provide the St. Johns River Water Management District with a tool to aid in the establishment of minimum groundwater levels within the basin.

This report presents the results of the third and final phase of a study of the Wekiva River Basin. Along with development and calibration of the model, sensitivity analysis was also performed, prior to conducting predictive simulations of system response to future groundwater use.

An investigation was undertaken to evaluate the effects of fluctuating water levels on the ecological functions of wetlands. Hopkins Prairie, in the Ocala National Forest, Florida, was chosen as a long-term ecological research site for this purpose.

The impact of lowering water level on deposition and redistribution of organic sediments was studied in eutrophic Newnans Lake, Florida. Phase I included data analysis and discussion relative to the impact of the drawdown on the flushing of organic matter and nutrients from the lake.

The impact of lowering the water level on deposition and redistribution of organic sediments was studied in eutrophic Newnans Lake, Florida. Phase II quantified the removal and redistribution of material from profundal and littoral sediments of the lake.

This document is the first of three volumes of planning documents in a program to develop a basinwide plan for the Econlockhatchee River. This volume contains reports prepared by scientists and planners who studied the environment and resources of the basin. This volume presents an inventory and presents management suggestions of a general nature.

This project was undertaken to determine values and locations of existing markets for a whole fish product, to examine potential domestic and export markets for food source components derived from gizzard shad, and to investigate potential for industrial market applications from harvested fish.

A study of the wetland-dependent birds and their vegetative food and habitat in South and Fox lakes, Brevard County, Florida, performed March-November 1990. The objectives of this study were to map the submerged aquatic vegetation of the lakes, describe the habitats used by wetland-dependent birds of the area, and evaluate the lakes for use by wetland-dependent birds.

The primary purpose of this study was to provide the technical basis needed to determine the optimal allocations of groundwater resources in eastern Orange and Osceola counties.

The Upper Etonia Creek Basin (UECB), located in parts of Alachua, Bradford, Clay, and Putnam counties, is part of the Lower St. Johns River Basin. The study evaluated long-term changes and trends in lake levels in the UECB, including changes to rainfall, evapotranspiration, groundwater levels, and water use in the basin.

In recognition of the problems and potential values of Lake Apopka, the Florida Legislature, in 1985, approved funds to study feasible means of restoring the lake. Part of this approval was to design a study for better understanding of the external and internal nutrient inputs to the lake, which would result in the development of a nutrient budget for the lake.

This document was prepared to comply with the requirements of Section 373.207, Florida Statutes. It includes an inventory of abandoned artesian wells in the St. Johns River Water Management District in 1990 and a work plan for controlling or plugging inventoried wells.

The purpose of the phase I modeling effort of this project was to synthesize boundary conditions and estimate regional aquifer parameters to support the phase II and III modeling tasks. This effort required the construction of a regional, three-dimensional, steady state groundwater flow model.

This manual is in three volumes. Volume 1 contains summaries of basic information on the primary potential sources of contamination, summaries of the aquifer protection tools available to local governments, and a chapter on the decision-making process. Volume 2 includes more detailed planning and regulatory information and the tools available to local governments to help prevent contamination. Volume 3 consists of appendices.

Hopkins Prairie was identified by the St. Johns River Water Management District as the site for a long-term research project to examine the effects of hydrology on wetland ecological functions. This part of the study examines the effects of water level and season on plant community dynamics and the distribution of some nutrients in the prairie.

This paper presents the results of a study of the baseline vegetation conditions in the Apopka Marsh Demonstration Project. Data collected during this study provided a pre-flooding reference point for comparison with future evaluations as the marsh developed.

This study evaluated the effects of hydrology, particularly fluctuating water levels, on soil water (interstitial porewater) chemistry in Hopkins Prairie, Ocala National Forest, Florida.

The process is a means of using naturally occurring bacteria that require oxygen for growth to biologically alter the offensive characteristics of organic waste. This was a study to determine how well the Bioferm process would work on waterhyacinths and gizzard shad removed from Lake Apopka in an effort to lower pollutant levels in the lake.

The lakes surveyed were Beauclair, Dora, Eustis, Griffin, Harris, Weir, and Yale. The resulting data were used to produce bathymetric and sediment thickness maps, hyposographic curves relating lake water level to lake volume and surface area, and curves relating to sediment volume and surface area to sediment thickness in each lake.

Leatherleaf fern is the most valuable floriculture crop produced in Florida. Almost all of it produced in the state occurs on land under the jurisdiction of the St. Johns River Water Management District. This study was undertaken to enable the district to make more informed decisions about irrigation water application rates and methods of application necessary to protect leatherleaf fern from cold.

This study was designed to provide information about the quantities, composition, and sources of suspended matter in Turkey Creek.

This report discusses the design and operation of a 1989 study of muck sediments in the Indian River Lagoon, including maps developed specifically for the study.

This report details the methodology of determining the water depth and the thickness of the organic sediment layer in South and Fox lakes.

This document was prepared to comply with the requirements of Section 373.207, Florida Statutes. It includes an inventory of abandoned artesian wells in the St. Johns River Water Management District in 1989 and a work plan for controlling or plugging inventoried wells.

This survey was a test of the time domain electromagnetic geophysical method. The objectives of the survey were to map the stratigraphy of the geologic section and to determine the depth to saline water.

Hopkins Prairie was identified by the St. Johns River Water Management District as the site for a long-term research project to examine the effects of hydrology on wetland ecological functions. This part of the study examines the effects of hydrology and season on plant biomass production and species composition in the prairie.

This study was conducted to gather baseline information on the effects of wetland hydrology and other physical and chemical parameters on the aquatic microinvertebrate community of Hopkins Prairie.

The potential environmental and ecological effects of a drawdown or enhanced lake level fluctuation program for Lake Apopka were assessed as a part of the Lake Apopka Surface Water Improvement and Management Plan initiative. This assessment was accomplished through extensive literature reviews, personal interviews, and evaluations of existing studies on Lake Apopka.

The St. Johns River Water Management District contracted HydroGeoLogic to conduct a modeling study of the Geneva freshwater lens system in the upper Floridan aquifer in Seminole County. The objectives were to adopt and calibrate a two-dimensional cross-sectional model and a three-dimensional density-dependent model for simulating groundwater flow and chloride transport in the system.

This study was undertaken to evaluate the potential to conserve groundwater used in seepage irrigation by implementing a recycling system for the runoff water. Preliminary water quality testing was performed to better understand the influence of the recycling process on the nutrient discharge from the field.

The purpose of this study was to provide baseline hydrogeological data for evaluating the water supply potential of the Bull Creek Wildlife Management Area.

The purposes of this study were to develop an evaluation procedure and associated software for performing a socio-economic assessment on a water project and to apply this methodology to the Lake Apopka Basin in central Florida.

A bathymetric survey of Lake Apopka was conducted in response to instruction from the Florida Legislature to begin pilot studies for restoring the lake’s water quality.

The purpose of this project was to provide baseline data in order to evaluate the potential of extensive fish harvesting as a restoration technique for Lake Apopka as well as other eutrophic (nutrient, overproductive) Florida lakes.

This document contains agricultural water use information collected from 1982 to 1988.

This document is a categorized bibliography of references which formed the basis for a review and synthesis of the reconnaissance profile of the Paynes Prairie Basin, Special Publication SJ88-SP4.

The objective of this report was to integrate and summarize relevant scientific information concerning this basin into a single reference in order to facilitate decision-making processes in basin management.

This report presents the results of a seismic reflection survey of Lake Apopka.

Summary not available.

This document was prepared to comply with the requirements of Section 373.207, Florida Statutes. It includes an inventory of abandoned artesian wells in the St. Johns River Water Management District in 1988 and a work plan for controlling or plugging inventoried wells.

This report defines and discusses the objectives of the agricultural water use survey proposed by the St. Johns River Water Management District.

This report includes a history of cultural eutrophication in Lake Weir, the important causes responsible for deterioration of water quality, the current status of the lake, and a management plan designed to maintain/restore water quality in the lake.

This report was prepared to evaluate, via the existing literature, the feasibility of sediment removal as a means to restore Lake Apopka and to evaluate the market potential for recovered sediment and develop a cost/benefit analysis for using sediment removal to restore Lake Apopka.

This report presents the results of a literature review and preliminary feasibility analysis assessing in situ sediment decomposition as a technique for oxidizing organic lake sediments and decreasing sediment nutrient loading to the water column.

This document was prepared to comply with the requirements of Section 373.207, Florida Statutes. It includes an inventory of abandoned artesian wells in the St. Johns River Water Management District in 1986 and a work plan for controlling or plugging inventoried wells.

This document is a categorized bibliography of references, which formed the basis for Special Publication SJ87-SP3.

The objective of this report is to integrate and summarize relevant scientific information concerning the named lakes into a single reference in order to facilitate decision-making processes in basin management.

This report consists of 325 pages of irrigation data.

This report presents the data, findings, and pertinent details of projects that have used chemical precipitation of phosphorus as a lake restoration technique.

This report contains a literature review relevant to buffer zones, a physical and ecological description of the Wekiva Basin, and a review of statutory and permit criteria that relate to the protection of the water resources of the basin. A methodology is then developed for determining buffer zone requirements.

This document was prepared to comply with the requirements of Section 373.207, Florida Statutes. It includes an inventory of abandoned artesian wells in the St. Johns River Water Management District in 1987 and a work plan for controlling or plugging inventoried wells.

This document was prepared to comply with the requirements of Section 373.207, Florida Statutes. It includes an inventory of abandoned artesian wells in the St. Johns River Water Management District in 1985 and a work plan for controlling or plugging inventoried wells.

This special report was prepared under authority contained in the Energy and Water Development Appropriation Act of 1984. The purpose of the interim water quality plan for the St. Johns River system was to prepare a plan upon which future development actions within the basin could be evaluated.

At the request of the city of Palm Bay, the St. Johns River Water Management District agreed to provide assistance in defining the zone of influence for the existing Port Malabar wellfield. This report documents the findings.

This document was prepared to comply with the requirements of Section 373.207, Florida Statutes. It includes an inventory of abandoned artesian wells in the St. Johns River Water Management District in 1983 and a work plan for controlling or plugging inventoried wells.

This manual provides a reference in proper procedures for collecting water quality data.

This document was prepared to comply with the requirements of Section 373.207, Florida Statutes. It includes an inventory of abandoned artesian wells in the St. Johns River Water Management District in 1984 and a work plan for controlling or plugging inventoried wells.

The primary objectives of this study were to monitor specific agricultural pumps in the upper basin of the St. Johns River and determine “loading” rates to the canals and the river, and to perform sediment coring and bathymetric transect studies on the chain of six lakes in the Upper St. Johns River Basin. Appendices make up more than half of this document.

This report provides documentation of how to record custody of a sample from collection to its introduction as evidence.