Freshwater Flows to Northeastern Florida Bay

In 1995, the U.S. Geological Survey (USGS) began a study to gage several major creeks that discharge freshwater into northeastern Florida Bay. This study provides flow, salinity, and water-level data for model development and calibration and also provides baseline data for other physical, biological and chemical studies being conducted in the area. The monitoring network provides coastal discharge data for the majority of estuarine creeks in northeastern Florida Bay. The timing and distribution of freshwater deliveries to northeastern Florida Bay have been documented since 1996. In 2003 the USGS coastal and estuarine unit also began calculating nutrient loads at selected sites in northeastern Florida Bay and along the southwestern Everglades coast. The larger network has provided discharge information to researchers to develop nutrient budgets and loading (Rudnick, 1999; Sutula and others, 2003; Davis, 2004; and Levesque, 2004).

In South Florida, changes in water-management practices to accommodate a large and rapidly growing urban population along the Atlantic coast, as well as intensive agricultural activities, have resulted in a highly managed hydrologic system. This managed system altered the natural hydrology of the Everglades ecosystem, including Florida Bay. During the last few decades, Florida Bay has experienced seagrass die-offs and algal blooms. Both are signals of ecological deterioration that has been attributed to increases in salinity and nutrient content of bay waters. With plans to restore water levels in the Everglades to more natural conditions, changes also are expected in the amount and timing of freshwater discharge through the major creeks into Florida Bay. Flow through the estuarine creeks through the Buttonwood Embankment and into Florida Bay is naturally controlled by the water level in the Everglades; regional wind patterns; and to a lesser extent, tides. Florida Bay restoration requires an understanding of the linkage between the amount of freshwater flowing into the bay and the salinity and quality of the bay environment. Historically, there has been no accurate quantification of the amount of freshwater being discharged into Florida Bay from the mainland due to the difficulties of accurately gaging flows in shallow, bi-directional, and vertically stratified streams. The project objectives are to determine the quantity, timing and distribution of freshwater flow into Florida Bay and adjacent estuaries, determine baseline hydrologic conditions and provide information on hydrologic change during the restoration process. This project helps determine how freshwater flow affects the health of Florida Bay, a critical component of the CERP, and how changes in water-management practices upstream (Taylor Slough and C-111 basins) directly influence flow and salinity conditions in the estuary.

The project managers for this study include Eduardo Patino (1995-2000), Clinton Hittle (2001-2003), and Mark Zucker (2003 -present).