The South Florida Ecosystem Restoration Program is an intergovernmental effort, involving a number of agencies, to reestablish and maintain the ecosystem of south Florida. One element of the restoration effort is the development of a firm scientific basis for resource decision making. The U.S. Geological Survey (USGS), one of the agencies, provides scientific information as part of the South Florida Ecosystem Restoration Program. The USGS began their own program, called the South Florida Ecosystem Program, in fiscal year 1995 for the purpose of gathering hydrologic, cartographic, and geologic data that relate to the mainland of south Florida, Florida Bay, and the Florida Keys and Reef ecosystems.

Over the years, the construction of canals and levees has altered the natural hydrologic conditions of the Everglades. The canals and levees were constructed to convey water, prevent flooding, and store water in conservation areas for future use. The U.S. Army Corps of Engineers (COE) in Jacksonville, Fla., is planning to construct gated spillways and culverts to allow for the restoration of natural sheetflow conditions to Everglades National Park (ENP). These proposed changes may further affect the hydrologic conditions of ENP and other parts of the ecosystem, thus leading to the following questions:

• Is ground water flowing to Biscayne Bay a significant component of the water budget in south Florida?
• Would the quantity of ground water flowing to Biscayne Bay be greatly affected by changes in the operation of gates and control structures in canals?
• How much change in ground-water discharges to Biscayne Bay has occurred due to modifications to the hydrologic system?

Federal, State, and local agencies need to know the effect that changes in the operation of gates and control structures in canals will have on the water-budget components of the natural water systems in south Florida, including ground-water flow to Biscayne Bay.