The altering of surface water flows to the Everglades will require managers to understand the effects of those altered flows. Shark Slough is the "heart" of the Everglades National Park, and monitoring coastal flows and nutrient loads from a large part of the Shark Slough will provide managers with baseline information pertaining to the effects that altered upgradient freshwater flows have on the southwest coastal area. The western boundary of the Everglades is a valuable asset to the overall Everglades system. Hydraulic data for this area will help provide a more complete understanding of the Everglades system.

BACKGROUND NARRATIVES

Project Summary: The four year study will provide data on the amount of water and nutrient loads discharged from three rivers along the southwest coast of Florida. Three stations have been established on the Broad, Harney, and Shark Rivers that use in situ sensors to collect continuous water-velocity, water-level, and water-salinity data. Monthly field trips to the stations are used to maintain the in situ sensors and to collect water-discharge measurements and water-quality samples. The in situ data and the monthly data will be used to develop relations between water discharge and nutrient loads for the three stations. The quantification of water discharge and nutrient loads is needed to observe changes in this area as water releases and pollution control methods for the Everglades are altered. Additionally, the data from this study can be used by other scientists conducting ecological studies in the estuarine area and for computer models.

Project Justification: The study will provide information on the quantities of water discharge and nutrient loads from three major rivers that receive water from the Shark Slough drainage area. The estuarine area is a highly productive area providing habitat for a variety of wildlife and recreational activities. The effects of altering water flows and pollution control methods in the upgradient areas of the Everglades may affect the downstream estuarine area. Water managers need to understand these effects in order to make informed decisions about changes that could affect the embayments along the southwest coast. Scientists studying the ecology of the area also benefit from the availability of water-discharge and nutrient-load data for the three rivers and can use the data to supplement their studies.

Project Objectives: The study will provide water-discharge and nutrient-load data for the Broad, Harney, and Shark Rivers along the southwest coast of Florida. The data can be used by scientists studying systems in the estuarine area or in upgradient areas of Shark Slough. The three river stations are instrumented with sensors to collect continuous water-velocity, water-level, and water-salinity data. Upward-looking acoustic Doppler profilers (ADP) are used to collect water-velocity data, vented-pressure transducers are used to collect water-level data, and four-electrode conductance sensors are used to measure salinity. Monthly field trips to the stations are made to clean and calibrate the sensors and collect water-discharge measurements and water-quality samples. Water discharge measurements are made using a boat-mounted acoustic Doppler current profiler. Water samples are collected using a modified equal-width method for depth and width averaging of samples. The samples are analyzed for total and dissolved nitrogen, total and dissolved phosphorus, and specific conductance. The in situ data and the monthly data will be used to establish velocity- stage-discharge relations and discharge-nutrient load relations. The relations will be used to pro- vide a continuous record of water discharge and nutrient loads for the three stations for the duration of the study.

WORK PLAN

Overall: The three stations on the Broad, Harney, and Shark Rivers will continue to be visited monthly during 1998. The location of the three stations are shown in figure 1. The monthly visits will be used for the maintenance, cleaning, and calibration of the in situ sensors. Monthly visits also will continue to be used for the collection of water-discharge measurements and water-quality sampling. Continuous data collection will continue through FY 1998. The continuous data collection sensors include upward looking ADP's to continuously monitor water velocity at the Broad, Harney, and Shark River stations. Additionally, continuous water-level, water-temperature, and specific conductance data will be collected.

Monthly discharge and water-quality data will be collected throughout the year. Routine field data collection includes multiple measurements of discharge at the Broad, Harney, and Shark River stations to establish velocity-area-discharge ratings. Collection of water-quality samples during ebb, flood, and slack tides at the three stations also will continue through the year.

After preliminary velocity-stage-discharge relations are established for the three stations, discharge will be measured at several selected river cross sections. These measurements will deter- mine whether discharge ratings for these other sections can be developed from the continuous- recording stations.

Monthly field trips for maintenance and data collection in remote areas generate high labor and travel costs. Data-collection methods are specialized and require highly-trained personnel. Personnel and travel requirements for the additional discharge data collection also contribute to the costs for this study. Vehicle travel time from Tampa to the staging point in Flamingo is seven hours. From Flamingo, it is a two-hour one-way boat trip to the station on the Broad River under good weather conditions, one and a half hours to the Harney River station, and one hour to the Shark River station.

Data collected for this study will be maintained by personnel from the US Geological Survey in Tampa, Florida, and the data will be stored in the USGS Automated Data and Processing Sys- tem (ADAPS). Documentation associated with data maintenance and supplemental data collected during the monthly visits will be stored at the USGS office in Tampa, Florida. The data will be available on a conditional basis throughout the duration of the study. All data from the study will be available after the final report is approved.

Timeline:
FY97

1. Install stations on the Broad, Harney, and Shark Rivers. (Levesque)
2. Verify sensor operations. (Levesque)
3. Make discharge measurements and collect water-quality samples on monthly schedule. (Feb 1997). (Levesque)
4. Begin velocity-stage-discharge analyses. (March 1997). (Levesque)
5. Submit proposal for FY98. (May 1997). (Levesque)
6. Submit abstract for Fragile Environments August 1997 meeting. (June 1997). (Levesque)
7. Complete poster for Flamingo Ranger District display. (June 1997). (Levesque)
8. Continue monthly station visits. (through 1998). (Levesque)
9. Continue velocity-stage-discharge analyses. (through 1998). (Levesque)
10. Maintain data (storage, editing, and analyses). (through 1998). (Levesque)
11. Begin writing draft report. (Levesque)

FY98
1. Continue monthly station visits. (Levesque)
2. Finalize velocity-stage-discharge relations and discharge-nutrient load relations. (Levesque)
3. Continue database maintenance. (Levesque)
4. Continue processing and analyzing data. (Levesque)
5. Submit proposal for FY99. (Levesque)
6. Submit abstract or fact sheet describing early study results. (Levesque)
7. Continue writing report. (Levesque)

FY99
1. Complete draft report and submit report for review by colleagues. (Levesque)
2. Remove stations from Everglades National Park. (Levesque)
3. Complete revisions to report. (Levesque)
4. Submit revised report for approval. (Levesque)
5. Complete final version of report. (Levesque)
6. Publish report. (Levesque)

Planned Deliverables/Products: An abstract detailing station installation and preliminary data analysis will be completed for the Fragile Environments meeting in August 1997. A poster describing the study will be provided to the Flamingo District park rangers for display in the Visitor Center by June 1997.
Preliminary velocity- stage-discharge relations will be completed near the end of FY97. Conditional continuous discharge values will be available following the completion of preliminary discharge ratings. A draft report will be available for colleague review in FY99. A final report will be published in FY99.

Planned Outreach Activities: A continuing collaboration with the Everglades National Park (ENP) personnel will provide a pathway for the dissemination of the data and results for this study. Additional collaboration with scientists from other USGS offices, University of Southwest Louisiana, US Army Corps of Engineers, South Florida Water Management District, and National Oceanographic and Atmospheric Administration is also planned.

New Directions, Expansion of Continuing Project (if applicable): The continuation of this study would be a significant benefit for the Everglades National Park monitoring program and other studies along the southwest coast of Florida. The continuous data stations could be maintained over a longer period of time to better characterize flow conditions from these three rivers. The installation of two or more continuous stations would enhance the existing network. Longer term data are desirable to short term data because climatic patterns may be anomalous to the shorter data period and may significantly bias the results of a short term study.

ACCOMPLISHMENTS, OUTCOMES, PRODUCTS, OUTREACH

Accomplishments and Outcomes, Including Outreach: A group peer review of surface-water studies was held in Miami in September 1996. During that meeting, modifications to the original plan of study were accomplished. Reviewers suggested installing a third station on the Broad River to measure more of the Shark Slough flows. The installation of the third station required the deletion of upgradient water-quality data collection, but it was agreed that water-quality sampling would be maintained at the three estuarine stations.

Gaging station installations at the Hamey and Shark Rivers were completed in October 1996. The upward looking velocity profilers (ADP) were installed at the Harney and Shark Rivers in November 1996. The Broad River gaging station installation was completed in December 1996, and the ADP was installed in January 1997. The Hamey River ADP was replaced in January 1997 because of equipment malfunctions.

Monthly discharge measurements and water-quality sampling at the 3 stations began in February 1997 and are ongoing. Monthly equipment maintenance and sensor calibrations are performed during the monthly station visits.

Metadata were provided to the Florida Department of Environmental Protection and to the U.S. Geological Survey Data are being stored and maintained in the USGS database in Tampa, Florida.

At this time (May 97), data analysis is beginning. The preliminary results indicate that the dominant forcing for the three rivers is barotropic, and the assumption of a progressive wave front is applicable for these stations. Water-quality data indicate relatively high nitrogen concentrations for a pristine area and very low phosphorus concentrations.

NEEDS

Required Expertise:
FY98
Hydrologist
Surface Water Specialist
Water Quality Specialist
Hydrologic Technicians
FY99
Hydrologist
Surface Water Specialist
Water Quality Specialist
Hydrologic Technician

Names of Key Project Staff:
FY98
Victor Levesque
Kathi Hammett
Yvonne Stoker
Paul Boetcher
Horace Blankenship
FY99
Victor Levesque
Kathi Hammett
Yvonne Stoker
Horace Blankenship

Major Equipment/Facility Needs: ENP houseboat for equipment removal.

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