Water Flows and Nutrient Loads to the Southwest Coast of Florida - A Study

U.S. Department of the Interior—U.S. Geological Survey Background

FLORIDA The embayments and estuaries of G Florida’s southwest coast are an inte- U L gral part of the south Florida ecosys- F Lostman’s River tem. Nutrients and other constituents O F LOCATION OF are transported to these coastal waters STUDY AREA M Broad River by surface water and ground-water E flow from the Everglades National X I Park (ENP) and the Big Cypress C O Preserve and by longshore and off- Harney River shore tidal currents. The coastal area is an essential breeding ground for many estuarine and marine species and is a EXPLANATION popular location for wilderness recre- POTENTIAL SITES ational pursuits as well as sport fish- Shark River ing. The volume of flow and the loads 0 5 MILES of nutrients being discharged from the 0 5 KILOMETERS streams draining the upland areas of ENP and Big Cypress Preserve currently are unknown. Figure 1. Location of study area.

As part of Everglades restoration under which to measure riverine flow. emphasis will be on data analysis and activities, the U.S. Army Corps of It has been almost thirty years since completion of the final report. Engineers may change the volume or any effort has been made to monitor A reconnaissance of the south- location of water deliveries to the flow characteristics continuously in west coastal rivers was conducted in ENP. Such changes could affect the the area. Significant technological volume or distribution of inflow and June 1996 to identify the significant advancements have occurred during associated constituents that are trans- this time and this new technology can flows in the study area and to select ported into the coastal waters of be applied to help obtain the informa- two sites for discharge and water southwest Florida. Proposals to tion needed to make informed quality data collection. It is anticipated change water deliveries to the Ever- decisions about the future of this that the two sites will be near two sites glades National Park and efforts to unique coastal area. studied by the USGS in the 1960’s. improve the environmental health of Potential site locations are shown in Florida Bay cannot be evaluated with- figure 1. Coordination with personnel out some understanding of the hydro- Plan of Study from the ENP, the South Florida Water logic and water-quality characteristics Management District, and the USGS of tidal rivers and coastal embayments In 1996, the U.S. Geological will be established early in the study to in the region. Survey (USGS) through the South identify additional hydrologic data The southwest coast of Florida is Florida Ecosystem Initiative began a collection needs. part of a wilderness area with unique 4-year study of the flow and nutrient hydraulic characteristics that has his- characteristics of two major streams The two sites will be instru- torically been described as the “River that drain parts of the Everglades mented with an upward looking acous- of Grass.” Flat terrain and lack of con- National Park. Efforts during the first tic doppler current profiler (index trolled topographic information has 3 years of the study will be devoted water velocity sensor), a water-level made it difficult to define drainage primarily to data collection and analy- sensor, and two specific conductance divides. Low gradients, coupled with sis. During the latter part of the third sensors. Data will be measured and tidal effects, create complex conditions year and during the fourth year, recorded at 15-minute intervals. Data will be collected during help characterize the current condi- Selected References monthly site visits by USGS person- tions for the two selected sites and nel. Stream discharge measurements explain the relation between upgradi- Fishman, M.J.,ed., 1993, Methods of will be made monthly at the instru- ent water levels and southwest coastal analysis by the U.S. Geological mented sites using an acoustic doppler stream flows, and the possible interac- Survey National Water Quality Lab- current profiler. Additionally, dis- oratory--Determination of inorganic tion between southwest coastal waters and organic constituents in water and charge measurements will be made at and the waters of Florida Bay. Flow other sites during the monthly visits. fluvial sediments: U.S. Geological and nutrient data can be used for Survey Open-File Report 93-125, Monthly discharge measure- descriptive purposes as well as serv- 217 p. ments will be used to develop dis- ing as input to hydrodynamic and charge ratings based on the in situ water-quality models that aid our Schomer, N.S. and Drew, R.D., 1982, An ecological characterization of the sensors and discharge measurements understanding of the south Florida lower Everglades, Florida Bay, and which will provide a continuous record ecosystem. the Florida Keys: U.S. Fish and of river discharge. The relation of Wildlife Service, Office of Biologi- upgradient water levels and coastal net cal Services, FWS OBS-82/58.1, water discharge will be evaluated. Collaboration and 246 p. Existing ENP and USGS water-level Partnerships sites will be used to collect the upgra- Simpson, M.R., and Oltmann, R.N., 1992, dient water-level data. The South Florida Ecosystem Discharge-measurement system Initiative provides a unique opportu- using an acoustic doppler current Water-quality samples will be nity for the USGS and the many agen- profiler with applications to large collected monthly at the instrumented cies conducting studies in the area to rivers and estuaries: U.S. Geologi- sites and periodically at two non- cal Survey Open-File Report 91-487, interact. Collaboration and partner- instrumented sites along the coast. 27 p. ships with those agencies are antici- Samples will be analyzed for total and dissolved nutrients and specific con- pated for this study. Stoker, Y.E., Levesque, V.A., and ductance. Additional water-quality Woodham, W.M., 1996, The effect This study will depend on a num- of discharge and water quality of the samples will be collected during times ber of existing rainfall and water-level of extreme hydrologic conditions. Alafia River, Hillsborough River, data collection stations that are main- and the Tampa Bypass Canal on tained by other agencies. Collabora- nutrient loading to Hillsborough Products tion with Everglades National Park, Bay, Florida: U.S. Geological National Oceanic and Atmospheric Survey Water-Resources Investiga- tions Report 95-4107, 69 p. Data collected for this study will Administration, and other USGS include discharge, concentrations of offices and divisions is anticipated to Stoker, Y.E., Levesque, V.A., and Fritz, nitrogen and phosphorus, nutrient support continued data collection at E.M., 1996, Discharge, water-quality loads, water velocity, water level, these sites. characteristics, and nutrient loads water temperature, and specific con- from McKay Bay, Delaney Creek, ductance from a minimum of two sites. Results of this study will be use- and East Bay, Tampa, Florida, 1991- All data will be available from the ful to the Everglades National Park, 93: U.S. Geological Survey Water- USGS Tampa office on a provisional National Oceanic and Atmospheric Resources Investigations Report 95- basis pending review and approval of Administration, U.S. Corps of Engi- 4167, 47 p. the final report. After approval for the neers, U.S. Fish and Wildlife Service, final report, all data will be considered U.S. Environmental Protection by Victor A. Levesque finalized and will be unconditionally Agency, U.S. Geological Survey, released to the public. Florida State Fish and Game Commis- For more information, please contact: Flow, nutrient concentrations, sion, South Florida Water Manage- and nutrient load data will provide ment District, universities, local agencies, and private interests who Victor Levesque part of the basic information needed U.S. Geological Survey to understand the hydrologic and may use the data as primary or 4710 Eisenhower Blvd., B-5 water-quality characteristics for a part complementary information in their Tampa, Florida 33634 of Florida’s southwest coast. The research, data collection activities, or (813) 243-5800 extension 167 analysis of these measurements will computer model development. [email protected]

July 1996 Fact Sheet FS- 179-96