Project Summary Sheet

Study Title: Freshwater Flows to Northeastern Florida Bay
Study Start Date: 1995 Study End Date: TBD
Web Sites: http:(//sofia.usgs.gov/projects/freshwtr_flow/)
Location (Subregions, Counties, Park or Refuge): Miami-Dade and Monroe Counties, Everglades National Park
Funding Source: USGS Greater Everglades Priority Ecosystems Science (GE PES), U.S. Army Corps of Engineers (USACE)
Principal Investigator(s): Mark Zucker
Study Personnel: Jeff Woods, Barclay Shoemaker, Shane Ploos, Christrian Lopez, Carrie Boudreau, Stephen Huddleston
Supporting Organizations: USACE, South Florida Water Management District (SFWMD), Everglades National Park (ENP)
Associated / Linked Studies: Southwest Florida Coastal and Wetland Systems Monitoring, USGS Coastal Gradients, Tides and Inflows in the Mangroves of the Everglades (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, Dynamics of Land Margin Ecosystems: Historical Change, Hydrology, Vegetation, Sediment, and Climate, Southern Inland and Coastal Systems (SICS) Model Development, Hydrology Monitoring Network: Data Mining and Modeling to Separate Human and Natural Hydrologic Dynamics, Compilation, Integration, and Synthesis of Water Quality and Flow Data for Assessing Nutrient Flux to South Florida Coastal Ecosystems, South Florida Surface Water Monitoring Network for the Support of MAP Projects (known as EDEN, Everglades Depth Estimation Network), Effects of hydrological restoration on manatees: Integrating data and models for the Ten Thousand Islands and Everglades, FIU-Long Term Ecological Research (LTER), ENP Marine Monitoring Network, SFWMD Everglades Program, SFWMD Minimum Flows and Levels for Florida Bay.

Overview & Objective(s): The project objectives are to: (1) determine the quantity, timing and distribution of freshwater flow through estuarine creeks into northeastern Florida Bay (Fig. 1); (2) for Everglades modelers, scientists, and managers, provide up to 31 days of real-time hydrologic data, provide published unit value data on the South Florida Information Access website (SOFIA), and provide station manuscripts for the annual surface water data report (Fig. 2); (3) advance acoustic methods and technology for gaging estuarine creeks; and (4) advance methods and technology for computing continuous monitoring record (e.g. salinity; Fig. 2). Flow, water-level, salinity, and temperature data are collected at the estuarine creeks that connect the Everglades wetland with Florida Bay (Table 1). This project provides flow data critical for addressing nutrient loading and the impact of water quality on Florida Bay. The USACE, SFWMD, USGS, ENP and other agencies as well as universities currently are using the data from this study to answer specific research questions that will directly benefit the Everglades restoration effort.

Figure 1: (above) Monitoring stations in northeastern Florida Bay and Joe Bay. [larger image]

Figure 2: (above) Example of a real-time data hydrograph. [larger image]

Table 1: Florida Bay monitoring stations and locations

Status: On-going

Recent Products: (1) Published unit values of water level, discharge, salinity, and temperature are available from 1996 to 2000. Data is available in Data Series Report 105 Hittle and Zucker (2004) and on SOFIA at (http://water.usgs.gov/pubs/ds/ds105/, http://sofia.usgs.gov/exchange/patino/patinoflow.html); (2) Poster titled Estimation of Freshwater Flow to Joe Bay, South Florida; (3) Published fact sheet (FS 2004-3129) "Hydrologic Characteristics of Estuarine River Systems within Everglades National Park." (http://water.usgs.gov/pubs/fs/2004/3129/) (4) Published unit values of water level, discharge, salinity, and temperature are available from 2001 to 2004 available on SOFIA; (5) Clickable map of the coastal network real-time data for scientists and resource managers available on SOFIA; (6) Formal presentation to the USACE in Jacksonville, FL in January 2005; (7) Abstract and poster summarizing coastal nutrient loads presented at the 2005 Florida Bay Conference (Shoemaker and others, 2005); (8) Circular article for the special estuaries addition covering Florida Bay hydrology during the 2004 hurricane season (Woods, in press); (9) Abstract and poster on availability of published hydrologic data on SOFIA (Zucker and others, 2006) and the estuarine creek response to hurricanes in 2004 and 2005 (Woods and others, 2006) presented at the 2006 GEER Conference in June 2006; (10) Contracted USGS National Mapping Division to resurvey five gaging stations to verify and correct datums for improving flow and water level calculations (B Glover, USGS, pers. commun., 2006) (11) Provisional nutrient loading data at West Highway Creek provided to SFWMD for the assessment of algal blooms in Florida Bay (South Florida Water Management District, 2006) (12) Abstract prepared in collaboration with Steve Davis at Texas A&M University for an LTER Scientists Conference (Davis and others, 2006) (13) Updated Florida Bay metadata posted on SOFIA.

Planned Products: (1) Publish unit values of water level, discharge, salinity, and temperature for water year 2006 available on SOFIA; (2) Collaborative journal article using flow data from Freshwater Flows to Florida Bay Project and water-quality data collected by the Coastal Gradients Project titled "Estimates of Nutrient Loads at West Highway Creek in Northeastern Florida Bay" (in preparation); (3) Journal article titled "Spatial and temporal salinity patterns in Joe Bay, Everglades National Park" (in preparation); (4) Data Series Report or Open File Report documenting the 2001-2005 published data set; (5) Quality-assured, published ground-water data at Upstream Taylor River (1999-2006) on SOFIA; (6) Continued rating development at the recently installed East Creek in Little Madeiria Bay station to evaluate the utility of hydrologic correlation.

Specific Relevance to Information Needs Identified in DOI's Science Plan in Support of Ecosystem Restoration, Preservation, and Protection in South Florida (DOI's Everglades Science Plan) [See Plan on SOFIA's Web site: http://sofia.usgs.gov/publications/reports/doi-science-plan/]:

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 Department of the Interior (DOI) science plan (specifically, the C-111 Spreader Canal and CSOP; Additional Water for ENP and Biscayne Bay Feasibility Study; and Florida Bay and Florida Keys Feasibility Study) by (1) providing baseline hydrologic data for model calibration and verification, and for resource management; (2) providing long-term hydrologic and water quality data to determine trends in hydrologic response to storms, sea level rise, and restoration activities; (3) quantifying discharge at estuarine creeks to answer quantity, timing and distribution questions (Fig. 3); (4) quantifying discharge at estuarine creeks for nutrient load calculations (Fig. 4); (5) providing temperature data for biological studies; and (6) providing salinity data to support restoration criteria (i.e., performance measures).

Figure 3: (above) Distribution of flow from nine monitoring stations in northeastern Florida Bay, 1996 to 2005. [larger image]

Figure 4: (above) Total phosphorus loads (in metric tons) at West Highway Creek during 2003-06. The data are provisional and were collected as part of the USGS Coastal Gradients Project. [larger image]

Three restoration questions were stated in the executive summary of the DOI Science plan (p. 1) and maximizing cost-share opportunities and science coordination were emphasized. This study supports restoration question 1: "What actions will improve the quantity, timing, and distribution of clean freshwater needed to restore the South Florida ecosystem?" 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 has been documented since 1996 (Fig. 3). In 2003, the USGS coastal and estuarine unit also began calculating nutrient loads (Fig. 4) at selected sites in northeastern Florida Bay and along the southwestern Everglades coast. The larger network has provided discharge information to researches to develop nutrient budgets and loading (Rudnick, 1999; Sutula and others, 2003; Davis, 2004; Levesque, 2004).

USGS synthesis teams have been coordinated to assess nutrient flux to South Florida coastal ecosystems (McPherson and others, 2006) and to conduct data mining and modeling to separate human and natural hydrologic dynamics (Conrads and others, 2005). The need to comprehensively address recent algal blooms in Blackwater Sound and adjacent basins has fostered a collaborative effort between the USGS and Federal, State, and local partners to determine the source of the problem and understand the persistence of the blooms (South Florida Water Management District, 2006).

Additional funding from the USACE and ENP-CESI has allowed PES to commit to sustainable funding levels for future years (Fig. 5). The USACE has provided funding since 2001 as part of the Freshwater Flows to Northeastern Florida Bay: Data Collection Network in Support of C-111 Basin Studies program. The CESI program has provided funding over a 3-year period to support the monitoring in Joe Bay (http://sofia.usgs.gov/projects/joe_bay/). Funding will be available through fiscal year 2007.

It is well recognized that maintaining funding for long term data collection is difficult, and the development of program with existing and new partners is a high priority. The northeastern Florida Bay network is one component of a larger integrated network that includes the southwest coast (Shark Slough), the freshwater/mangrove transition zone (Coastal Gradients Projects). Funding for the integrated network includes PES, USACE, and the funding sources described above. The coastal projects are interdependent in terms of the physical, chemical, and hydrological data needed to assess the potential spatial and temporal changes as CERP restoration proceeds. The collective scope of the two projects allows for a more sustainable long-term data and research program than would otherwise be possible.

Figure 5: Example of cost-share opportunities in FY2004. [larger image]

The DOI science plan has provided four criteria for prioritizing the science needs for restoration and resource management (p. 11). The criteria and the applicability of the Freshwater Flows to Northeastern Florida Bay project to each are summarized below.

1) The relevance of the science effort to improving understanding of the ecological and hydrological processes affecting DOI lands and resources. This project has been tasked since 1995 to develop techniques to measure and compute continuous discharge affected by wind and tide along the South Florida coast. Methods have been developed to quantify coastal discharges (Hittle and others, 2001; Morlock and others, 2002; Ruhl and others, 2005) and published data has been shared with our partners to improve our understanding of the south Florida estuaries (http://sofia.usgs.gov/exchange/patino/patinoflow.html). Since the development and application of index velocity techniques in South Florida estuaries, new methods and instrumentation have been utilized to improve the quantification of discharge. Acoustic Doppler velocity meters with up-looking acoustic beams have been utilized to quantify discharge in bidirectional rivers (i.e., Card Sound Canal). Up-looking acoustic sensors and pressure transducers have been employed to measure water level rather than the standard stilling well at some locations. Instrumentation such as DGPS and sonar are being used to more accurately measure discharge in Florida Bay channels with dense sea grass beds (Criales and others, 2003). Also acoustic Doppler velocimeters are being used to measure wetland velocities in Taylor Slough and the C-111 Basin. Additional research benefits include the development of nutrient loading methods for three estuarine creeks (Shoemaker and others 2005); the evaluation of estuarine creek responses during the 2004-2005 hurricane season (Woods and others 2006); and the evaluation of minimum flows and levels in Florida Bay using real-time data from the National Water Information System at (http://waterdata.usgs.gov/fl/nwis/rt and http://fl.water.usgs.gov/Miami/hurricane/) (Bennett, SFWMD pers. commun., 2006).

2) The applicability of the science to multiple DOI restoration objectives or multiple projects. This project provides data sets for (1) various modeling efforts (SICS, TIME, Florida Bay Hydrodynamic Model) utilized by the USGS, USACE, ENP, SFWMD, and universities; (2) nutrient loading assessments by FIU and SFWMD; and (3) salinity box modeling by Marshall and others (2002) and Nuttle (2002). In addition, research on mercury loading in Florida Bay utilized computed flow data (Rumbold and others 2001).

3) Synthesis and sequencing to address the most urgent management information needs. The project supports various synthesis and modeling efforts. Examples of USGS synthesis projects include the Compilation, Integration, and Synthesis of Water Quality and Flow Data for Assessing Nutrient Flux to South Florida Coastal Ecosystems project, and the Hydrology Monitoring Network: Data Mining and Modeling to Separate Human and Natural Hydrologic Dynamics project. Other synthesis projects utilizing our data sets include (1) the SFWMD Everglades Consolidated Reports and the more recent algal bloom problem along US-1 (South Florida Water Management District, 2006); the FIU Long Term Ecological Research, Florida Coastal Everglades project; the USACE Florida Bay and Florida Keys Feasibility Study.

4) Maximization of cost-share opportunities and science coordination across bureaus or with DOI's CERP partners. This project receives funding from PES and USACE, and it benefits from additional CESI funded work in Joe Bay. Funding for the Southwest Florida Coastal and Wetland Systems Monitoring project is fully funded by PES, whereas the Coastal Gradients of Flow, Salinity, and Nutrients project is fully funded by CERP RECOVER. An example of the cost-share in fiscal year 2004 is shown in figure 5.

This study supports the C-111 Spreader and CSOP projects (p. 71), as it provides (1) baseline data (flow, salinity, and rainfall) for change detection throughout the construction process and modeling, (2) critical coastal discharge data for water quality assessments such as nutrient loading, and (3) hydrologic data to calibrate models or verify models for predictions of salinity.

In addition, this study supports the Additional Water to Everglades National Park and Biscayne Bay Feasibility Study (p. 74) by providing (1) baseline data to assist with determining how restoring natural flows in Taylor Slough will change the quantity, timing, and distribution of flows in Biscayne Bay and Florida Bay; (2) physical, chemical, and hydrologic data needed for environmental risk assessments of contaminants; and (3) rainfall data at three locations to enhance geospatial rainfall data coverage near the coast.

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

Key Findings:

1. From 1996 to 2005, Trout Creek has consistently contributed roughly 50% of the total flow to northeastern Florida Bay.
2. Roughly 70% of the freshwater flow into northeastern Florida Bay enters east of Taylor Slough.
3. Water level differences between Taylor Slough and the C-111 basin drive flow direction in the southeastern Everglades, which is a critical issue for contaminant transport, flood management, and saltwater intrusion concerns. For example, freshwater from Taylor Slough moves eastward towards western Joe Bay during major storms and is an important contributor of freshwater flow to Florida Bay through Trout Creek.
4. Hydrologic Correlation 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 (Zucker, 2003).
5. Total flow The total annual flow to Northeastern Florida Bay for 2005 was the greatest measured since the project began in 1995. Coincidently, the lowest total annual flow to Northeastern Florida Bay occurred in 2004. The total annual freshwater flow to northeastern Florida Bay in 2005 equaled 499,362 acre-ft (AC-FT). Trout Creek and West Highway Creek accounted for 9.9% and 46.9% of the total flow, respectively. Mud Creek, Taylor River at Mouth, and McCormick Creek total flow accounted 8.1%, 7.9%, and 8.3%, respectively. Total annual flow at West Highway Creek and Trout Creek for 2005 was 249% and 427% higher than for 2004.Total annual flow at Mud Creek, Taylor River, and McCormick Creek was 281%, 193%, and 383% higher, respectively, in 2005 than in 2004.
6. Flow distribution The flow distribution from five stations installed in water year 1996 (West Highway, Trout Creek, Mud Creek, Taylor River, and McCormick Creek) was discussed by Hittle (2000) and Hittle and others (2001). Total annual flow in 1996, 1997, 1999, 2001, 2002, 2003, and 2005 was near or above 300,000 AC-FT whereas total annual flow in 1998, 2000 and 2004 was less than 300,000 AC-FT equaling 284,630 AC-FT, 231,560 AC-FT, and 154,130 AC-FT, respectively. Total annual flow in 2000 and 2004 coincided with drought-like conditions in south Florida, even though 2004 was considered an active hurricane season with four named storms impacting the state of Florida. Hittle and others (2001) discussed the flow distribution during the El Nino of 1998, in particular the impact on flow at McCormick Creek. Net negative annual flow was observed at McCormick Creek during the El Nino year of 1998 and during the drought year of 2000, but net negative annual flow was not observed during the drought year of 2004.
7. Salinity response in 2005 Hypersaline conditions at McCormick Creek coincided with the drought years 2000 and 2004 and non-drought years 1998, 1999, 2001 and 2005. In 2000, salinity conditions were greater than 35 ppt only at McCormick Creek. On the other hand, salinity conditions in 2004 and 2005 were greater than 35 ppt at West Highway Creek, Trout Creek, Mud Creek, Taylor River Mouth, upstream Taylor River, and McCormick Creek. Salinity throughout Joe Bay exceeded 40 ppt in 2005 (Fig. 11, Fig. 12, Appendix). Freshwater eventually was transported to northeastern Florida Bay in mid-June 2005. The salinity response in June 2005 was variable except for the stations downstream of water management structures (C-111 Canal). Monitoring stations in Long Sound and eastern Joe Bay reported rapid changes in salinity reaching 5 ppt or less within 1 week of water-management operations. Monitoring stations such as McCormick Creek and Taylor River at the Mouth, located in the more western portion of the study area, reported a more gradual change in salinity with the onset of freshwater input. McCormick Creek near Terrapin Bay, the most western station in the study area, dropped from a salinity of 50 ppt to roughly 30 ppt and remained elevated until the passing of Hurricane Katrina. The salinity conditions at Taylor River at the Mouth did not reach fresh-like conditions (< 5 ppt) until the passing of Hurricane Katrina reaching a 1 ppt by mid September 2005.
8. Salinity response in Joe Bay Peak salinity conditions reported in Joe Bay ranged between 36-40 ppt in 2004, while hyper-saline conditions (>40 ppt) were reported throughout Joe Bay in 2005. Hyper-saline conditions throughout Joe Bay occurred on May 15, 2006, and persisted at Joe Bay 1E (JB1E) and Joe Bay 8W (JB8W) until June 12, 2006. Salinity at Joe Bay 2E and Joe Bay 5C dropped rapidly from roughly 40 ppt, on June 3, 2005 to between 1-2 ppt on June 24, 2005, as a result of water management operations and rainfall. Total discharge from the C-111 Canal at S-18C equaled 22,000 AC-FT in June 2005, along with nine days with at least 0.75 inches of rainfall at West Highway Creek. Salinity conditions at JB1E and JB8W decreased more gradually and reached conditions near 1.0 ppt on September 4, 2005. The brackish salinity pattern at JB1E prior to Hurricane Katrina is probably a function of the flow regime between Joe Bay and Snag Bay. From May to June 2005 flow was predominately from Snag Bay to Joe Bay, whereas from June to September 2005, flow was from Joe Bay to Snag Bay. In August 2005, the flow direction changed dramatically due to Hurricane Katrina and as a result, a substantial amount of water was transported from Joe Bay to Snag Bay.