Study Title: Freshwater Flows to Northeastern Florida Bay
Study Start Date: FY1995 Study End Date: TBD
Web Sites: http:(//sofia.usgs.gov/projects/freshwtr_flow/)
Location (Subregions, Counties, Park or Refuge): Dade and Monroe Counties, Everglades National Park
Funding Source: USGS Greater Everglades Priority Ecosystems Science (GE PES)
Other Complementary Funding Source(s): U.S. Army Corps of Engineers, Everglades National Park (CESI)

Principal Investigator(s): Mark Zucker, Clinton Hittle
Study Personnel: Jeff Woods, Marc Stewart, Rich Kachelriess, Jessica Adams
Supporting Organizations: U.S. Army Corps of Engineers, SFWMD, Everglades National Park
Associated / Linked Studies: Southwest Florida Coastal and Wetland Systems Monitoring, USGS Coastal Gradients, Tides and Inflow in the Mangrove Ecotone (TIME), Groundwater-Surface Water Interactions and Relation to Water Quality in the Everglades, Geology and Ecological History of the "Buttonwood Ridge" Region, Salinity Patterns in Florida Bay: A Synthesis, Interrelation of Everglades Hydrology and Florida Bay Dynamics to Ecosystem Processes and Restoration in South Florida, Southern Inland and Coastal Systems (SICS) Model Development, FIU-Long Term Ecological Research (LTER), Everglades National Park Marine Monitoring Network, South Florida Water Management District Everglades Program.

Overview & Objective(s): The project objectives are: 1) To determine the quantity, timing and distribution of freshwater flow through estuarine creeks into northeastern Florida Bay, 2) to provide real-time physical data to Everglades modelers and researchers, and 3) to advance accurate methods for gaging estuarine creeks. Flow, water-level, and salinity data are collected at the estuarine creeks that connect the Everglades wetland with Florida Bay. This project helps determine how freshwater flow affects the health of Florida Bay, a critical concern 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 U.S. Army Corps of Engineers (USACE), South Florida Water Management District (SFWMD), USGS, Everglades National Park (ENP) and other agencies as well as universities are currently using the data from this study to answer specific research questions that will directly benefit the restoration effort.

Specific Relevance to Major Unanswered Questions and Information Needs Identified: (Page numbers below refer to DOI Science Plan.)

This study supports several of the projects listed in the DOI science plan (specifically: C-111 Spreader Canal and CSOP; Additional Water for ENP and Biscayne Bay Feasibility Study; Florida Bay and Florida Keys Feasibility Study) by (a) providing baseline hydrologic data for model calibration and verification and for resource management; (b) quantifying discharge at estuarine creeks to answer the quantity, timing and distribution question; (c) quantifying discharge at estuarine creeks for load calculations; (d) providing temperature data for biological studies; (e) providing salinity data to support restoration criteria (i.e. performance measure)

This study supports the C-111 Spreader and CSOP projects (p. 71) as it (1) provides critical coastal discharge data for nutrient and pesticide loading to the bay and (2) provides salinity data to calibrate models or verify model predictions of salinity.

This study supports the Additional Water to Everglades National Park and Biscayne Bay Feasibility Study (p. 74) as it (1) provides critical coastal discharge data for nutrient and pesticide loading to the bay (p. 63) and (2) provides baseline data to assist with the question of how will natural flows in Taylor Slough will change the quantity, timing, and distribution of flows in Biscayne Bay.

This study supports the Florida Bay and Florida Keys Feasibility Study (p. 77) as it (1) provides baseline data to address the quantity, timing and distribution of freshwater flow to Florida Bay question, (2) provides basic hydrologic data to assist with model calibration and verification (p. 78) of the Florida Bay Hydrodynamic and the USGS TIME and SICS models, and (3) provides critical coastal discharge data for nutrient, pesticide, and mercury loading.

Key Findings:

1. From 1996 to 2003, Trout Creek has consistently contributed approximately 50% of the total freshwater flow to northeastern Florida Bay.
2. Roughly 70% of the freshwater flow into northeastern Florida Bay enters eastward of Taylor Slough.
3. Water level differences between Taylor Slough and the C-111 basin drive flow direction in the southeastern Everglades, which is critical issue for contaminant transport, flood management, and saltwater intrusion concerns.
4. Preliminary data suggests that annual flows are variable from year to year. For example, flows in 2000 were the highest since data collection was initiated in 1996. Conversely, flow in 2003 was considered a 'dry year' resembling flows observed during the drought year of 2000.
5. Hydrologic Correlation has been employed to estimate non-gaged estuarine creeks with reasonable success (i.e. Long Sound) but may not be applicable for other estuarine creeks in northeastern Florida Bay.
6. Hypersaline conditions have been routinely observed in the westernmost portion of the study area (i.e. McCormick Creek) but hypersaline conditions near or exceeding 40 ppt were observed bay-wide during the dry season of 2004 and relatively high salinities persisted during the wet season.

Status: On-going

Recent Products: Published unit values of water level, discharge, salinity, and temperature are available from 1996 to 2000. (http://sofia.usgs.gov/exchange/patino/patinoflow.html), Poster titled Estimation of Freshwater Flow to Joe Bay, South Florida.

Planned Products: Published unit values of water level, discharge, salinity, and temperature for water years 2001 through 2003. Fact Sheet and poster prepared for First National Conference on Ecosystem Restoration (NCER) in Orlando, Florida, December 2004.

WORK PLAN

Title of Task 1: Gaging Freshwater Flows into Northeastern Florida Bay
Task Funding: USGS Greater Everglades Priority Ecosystems Science (GE PES), USCOE C-111 Project
Task Leaders: Mark Zucker, Clinton Hittle
Phone: 305-717-5852, 305-717-5815
FAX: 305-717-5801
Task Status (proposed or active): Active and ongoing
Task priority: High
Time Frame for Task 1:
Task Personnel: Mark Zucker, Clinton Hittle, Jeff Woods, Rich Kachelriess, Marc Stewart, Jessica Adams

Task Summary and Objectives: Task 1 is the continuation of measuring freshwater flow from the Everglades wetlands into northeastern Florida Bay. Flow, water-level, salinity and temperature data are collected in real-time at monitoring sites in estuarine creeks and are transmitted via satellite to the USGS Center for Water and Restoration Studies in Miami, Florida.

The task objectives are: 1) to determine the quantity, timing and distribution of freshwater flow through estuarine creeks into northeastern Florida Bay (the Florida Bay and Florida Keys Feasibility Study (p. 77), 2) To provide real-time physical data to Everglades/Florida Bay modelers and researchers (Additional Water to Everglades National Park and Biscayne Bay Feasibility Study (p. 74), and 3) to advance accurate methods for gaging estuarine creeks.

Work to be undertaken during the proposal year and a description of the methods and procedures: Data collection includes continuous 15-minute interval measurements of water level, water velocity, salinity, and temperature data and periodic measurements of discharge for acoustic Doppler velocity meter (ADVM) calibrations at West Highway Creek, Stillwater Creek, Trout Creek, Mud Creek, Taylor River at Mouth, upstream Taylor River, McCormick Creek, and Jewfish Creek. Field data at the instrumented sites are recorded by an electronic data logger and transmitted every 4 hours by way of the Geostationary Operational Environmental Satellite (GOES) into the database of the USGS CWRS office. Non-transmitting stations where only discharge and water level are collected include East Highway Creek and Oregon Creek. Boat mounted acoustic Doppler current profilers (ADCP) are used to measure discharge in the estuarine creeks mentioned above. The ADCP uses the Doppler shift in returned acoustic signals reflected by particles suspended in the water to determine the velocity of moving water. Discharge and flow direction are calculated using the Doppler software package. The mean channel water velocity is calculated by dividing the total discharge (measured with the ADCP) by the cross-sectional area determined by the water level at the time of measurement. The cross-sectional area is computed by using the site-specific stage area ratings, which is a function of water level. Water-level data are collected with an incremental shaft encoder equipped with a pulley, stainless-steel tape, weight, and float inside an 8 in. (inch) polyvinyl chloride pipe stilling well. Salinity and temperature data are collected with YSI instrumentation (i.e. 600R, Optical Monitoring System). During routine station visits, these in-situ instruments are cleaned, calibrated (if necessary), and verified with laboratory standards. In essence, fouling and electronic errors are observed and datum corrections are applied accordingly. An independently calibrated YSI instrument is used during each field trip to verify in-situ salinities and temperatures. The independent YSI sensor is checked against a NIST laboratory certified thermometer in the lab periodically.