FLORIDA PROJECTS

• Aquifer Characterizations

• Availability of Water

• Climate Change and Hydrologic Extreme Events

• Ecosystems

• Hydrologic Modeling
• Analysis of Groundwater and Lake Level Data in the CFCA
• Coupled Groundwater and Hydrodynamic Surface-Water Modeling
• Deep-well injectate in Miami-Dade County
• Freshwater-Saltwater Interface in Broward County
• Groundwater Flow and Solute Transport Models
• Integrated Model of Surface-Water and Groundwater Flow
• Modeling Effects of Deepening the SJR Shipping Channel
• Simulation of Transient Groundwater Flow in East-Central FL
• Surface-Water and Groundwater Flows to Lake Tsala Apopka
• Surface-Water influx to the Biscayne aquifer in response to wellfields

• Surface Water

• Water Quality Conditions

• Wetlands

ABOUT FLORIDA SCIENCE

• Office Information:
  • Florida Water Science Center office locations
  • Information Requests

• National Information:
  • USGS Phonebook
  • USGS Science Strategy
  • Employment

Ask Florida USGS

Relative importance of surface-water and groundwater flows to Tsala Apopka Lake, west-central Florida

Project Chief: Scott McBride
Cooperator: Southwest Florida Water Management District (SWFWMD)
Period of Project: October 2009 - September 2014

Problem Statement

Figure 1. Location of the canals and flow-control structures in the Tsala Apopka Lake study area.

Previous and on-going studies have shown that a strong hydraulic connection exists between surface water and groundwater in the Tsala Apopka Lake area (fig. 1). Tsala Apopka Lake is a difficult resource to manage due to its complexity. Reliable data on the nature of the hydraulic connection between the lakes and wetlands and the Upper Floridan aquifer is scarce. Analytical water budgets have never been developed for the system. Understanding how water moves through the system and interacts with the underlying aquifer would give water managers better insight into how to manage the system.

Objectives

1) Assess the hydraulic connection of Tsala Apopka Lake with the Upper Floridan aquifer

2) Develop an analytical water budget for the lake system using both physical and remotely sensed hydrologic data

3) Develop an integrated surface water/groundwater model capable of evaluating the effects of climate changes, development, and alternative management approaches

One of the many wetlands found in the Tsala Apopka Lake system; photo by W. Scott McBride.

Approach

The surface-water component of the project involved implementing a hydrologic monitoring network. The data collected were used in conjunction with remote sensing techniques to calculate analytical water budgets. The hydrogeologic component of the study involved installing wells to monitor interactions between surface water and shallow groundwater, defining the hydrogeologic framework, and producing detailed potentiometric surface maps of the Upper Floridan aquifer in the vicinity of the Tsala Apopka Lake basin. The water quality and water chemistry component of the study involved collecting major ion, nutrient, isotope, and age dating samples from select groundwater and surface-water sites to evaluate the interaction of groundwater and surface water in the study area.

The development of an analytical water budget, evaluation of the hydraulic connection of Tsala Apopka Lake with the Upper Floridan aquifer, and the development of an integrated surface-water/groundwater model required an extensive data collection and data analysis program involving groundwater, surface water, rainfall, evapotranspiration, geology, and water-quality information. The SWFWMD collected stage data while the USGS measured discharge, developed rating curves for each structure, and quality assured stage data collected by SWFWMD. Rainfall and evapotranspiration data were measured using remote sensing techniques. Rainfall data was verified using data collected at existing gages run by USGS, SWFWMD, and other agencies.

The hydraulic connection between the Upper Floridan aquifer and the surface water system was evaluated using several methods. A detailed potentiometric surface map of the Upper Floridan aquifer in the study area was created twice per year (dry season and wet season) using a combination of monitoring wells and domestic wells. The SWFWMD agreed to install at least six well nests in the study area, consisting of one Upper Floridan aquifer well and one surficial aquifer well, which complemented several existing well nests. The well nests were used in the creation of potentiometric surface maps and also to evaluate water-level differences between the Upper Floridan aquifer, surficial aquifer, and the surface-water system. Water-quality samples were collected at select groundwater and surface-water sites to further evaluate the hydraulic connection between Tsala Apopka Lake and the Upper Floridan aquifer.

Information Product

A USGS Scientific Investigations Report (SIR) will describe the hydrology, water budget, water chemistry, and the surface-water/groundwater model of Tsala Apopka Lake in west-central Florida.