Helena M. Solo-Gabriele 2000 report http://sofia.usgs.gov/projects/index.php?project_url=levee_31 The primary objective of this investigation was to quantify seepage below Levee L31N. The amount of water lost to the L-31N Canal versus the fraction that flows below the canal was estimated. A conceptual model was developed for the site based upon results from an on-going stable isotope (oxygen -18 and deuterium) study. Quantification of seepage rates were based upon a computer model, MODBRANCH, which couples both groundwater and surface water flows. Particular attention was devoted to model performance under transient conditions caused by fluctuations in the stage of the L-31N Canal and pumping operations of the West Wellfield. In addition, an alternative leakage relationship based on reach transmissivity was incorporated into MODBRANCH; this relationship was believed to be more suitable for transient conditions. The reach transmissivity relationship was evaluated in comparison to MODBRANCH's existing leakage relationship, which is based on Darcian flow through the bed of the surface water channel. Modeling results were used to develop an algorithm for real time estimation of seepage beneath Levee L31N. It was expected that this algorithm would estimate seepage using head differences at monitoring stations in the vicinity of the levee. Plans to restore historical hydrologic conditions in the northeast section of Everglades National Park (ENP) include the raising of water levels in ENP and water conservation area 3B, which overlie the Biscayne aquifer, an extremely permeable aquifer. The increase in water levels is likely to cause an increase in seepage losses to the east. Quantifying this seepage loss is necessary for water management purposes as well as for models of the Everglades and coastal systems. Levee L-31N has been identified as a critical area for potential water losses. The L-31N study site included a wetland area within ENP on the west; the L-31N Canal flows from north to south through the longitudinal center of the site, and the eastern portion of the region is a suburban area of Miami which included a major municipal wellfield, the West Wellfield, and rock mining activities. This project was completed in 1999. The results are reported in Water-Resources Investigations Report 00-4066. 1950 199909 ground condition Complete None planned -80.58 -80.43 25.83 25.6 none flow models groundwater seepage surface water stable isotope hydrology ISO 19115 Topic Category environment geoscientificInformation inlandWaters 007 008 012 Department of Commerce, 1995, Countries, Dependencies, Areas of Special Sovereignty, and Their Principal Administrative Divisions, Federal Information Processing Standard (FIPS) 10-4, Washington, DC, National Institute of Standards and Technology United States US U.S. Department of Commerce, 1987, Codes for the identification of the States, the District of Columbia and the outlying areas of the United States, and associated areas (Federal Information Processing Standard 5-2): Washington, DC, NIST Florida FL Department of Commerce, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas, FIPS 6-3, Washington, DC, National Institute of Standards and Technology Miami-Dade County USGS Geographic Names Information System Everglades National Park none Central Everglades South East Coast L31N West Wellfield None. None. Helena Solo-Gabriele University of Miami Professor and Associate Dean for Research mailing address

Department of Civil, Arch., and Environmental Engineering P.O. Box 248294

Coral Gables FL 33124-0630 USA 305 284 2908 hmsolo@miami.edu http://fl.water.usgs.gov/PDF_files/wri00_4066_nemeth.pdf Figure 1. shows the location of study area PDF Project personnel included Mark Nemeth, Walter Wilcox, Alberto Herrera, Gurdun Ibler, Jennifer Loschak, Naila Hosein, and Timothy Desmarais Station location and description, and period of record data are stored for each sampling location in the USGS NWIS database. Nemeth, Mark S. Wilcox, Walter M.; Solo-Gabriele, Helena M. 2000 report USGS Water-Resources Investigations Report 00-4066 Tallahassee, FL U.S. Geological Survey accessed as of 11/16/2010 http://fl.water.usgs.gov/Abstracts/wri00_4066_nemeth.html Solo-Gabriele, Helena Wilcox, Walter 2000 report Coral Gables, Florida University of Miami, Dept. Of Civil, Arch, and Environmental Engineering Third Interim Technical Report for Isotopoic Study, Phase I accessed as of 11/17/2010 file is 23 Mb http://cae.miami.edu/~hmsolo/L31/enpfinaldraft_m4.pdf Nemeth, Mark S. Solo-Gabriele, Helena M. 200304 report Journal of Hydrology v. 274, issues 1-4 Amsterdam, the Netherlands Elsevier B. V. accessed as of 11/16/2010 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below by selecting the volume and issue number. http://www.sciencedirect.com/science/journal/00221694 Bigeleisen, J. Perlman, M. L.; Prosser, H. C. 1952 report Analytical Chemistry v. 24, n. 8, p. 1356-1357 Washington, DC American Chemical Society accessed as of 11/17/2010 The full article is available via journal subscription or single article purchase. The first page may be viewed on the website below. http://pubs.acs.org/doi/abs/10.1021/ac60068a025 Epstein, S. Mayeda, T. 1953 report Geochimica et Cosmochimica Acta v. 4, n. 5, p. 213-224 Oxon, United Kingdom Geochemical Society accessed as of 11/17/2010 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below by selecting the volume and issue number. http://www.sciencedirect.com/science/journal/00167037 Gehre, M. Hoefling, R.; Kowski, P.; Strauch, G. 1996 report Analytical Chemistry v. 68, n.24, p. 4414-4417 Washington, DC American Chemical Society accessed as of 11/17/2010 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below. http://pubs.acs.org/doi/abs/10.1021/ac9606766 Matsui, E. 1980 report Analytica Chimica Acta v. 120, p. 423-425 Amsterdam, The Netherlands Elsevier Science, B. V. accessed as of 11/17/2010 The full article is available via journal subscription or single article purchase. The abstract may be viewed on the website below by selecting the volume number. http://www.sciencedirect.com/science/journal/00032670 not available not available No test was performed but locations were determined using a "hand-held" GPS receiver which has an accuracy of roughly 100 feet. Work at Levee 31N began during the summer of 1997. The five AVM stations located along the levee were resurveyed to a consistent set of benchmarks. Data were been compiled for 3 rain gauging stations, 5 AVM stations, and 29 existing shallow groundwater monitoring stations. Five additional deep wells were been installed for water quality monitoring. One of the five deep wells was also utilized for continuous measurements of stage. Six vertical seepage meters were been installed along a transect that cuts across L31N. Several experiments were been conducted under different hydrologic conditions. Sampling and analysis for the stable isotopes and hydrologic data collection continued through February 1999. Computer input files were developed. Collected data were utilized in the development and calibration of a transient 3-dimensional groundwater/surface water model (MODBRANCH) to determine seepage rates beneath Levee 31N. The MODBRANCH code was modified to incorporate a "reach transmissivity" leakage option between the river and groundwater. This "reach transmissivity" relationship was successfully used for steady conditions at this site in a previous study. Calculation of canal seepage rates and calibration of the Levee 31N flow model were completed by February 1999. An empirical relationship between field data and seepage rates was determined for the site. The water resources investigation report describing the results of the Levee 31N study was completed and published in 2000. Seepage meter tests were performed at 6 sites in the vicinity of the L-31N Levee. These sites were located from 1.5 miles west to 0.2 miles west of Levee 31N within northeast Everglades National Park. Samples were collected during a period ranging from January 1996 to December 1998. The monitoring network was modified over time with an emphasis placed on sites within the focus area. Early during the sampling program only a few sites were tested on a non-regular basis. Beginning in February 1997, samples were collected on a regular monthly schedule. Furthermore, it is important to note that as the research continued, sites were continually added until the completion of sampling. Overall, 580 samples were collected at 26 different sites, which included the two lakes. Sample Collection All samples were collected in duplicate using glass scintillation vials. These vials were filled to the top with sample water and sealed with a screw-on top. A layer of parafilm was then wrapped around the vials in order to prevent evaporation. Samples were collected from groundwater, municipal pumping wells, surface water (including lakes), and rainwater. Groundwater samples were collected using a portable pump connected to a 12-volt battery. The intake end of the pump hose was lowered into the well casing while the outflow end was allowed to flow into the scintillation vial for sample collection. For shallow wells, the pump was allowed to draw water from the well for five minutes prior to sample collection to assure that a representative sample was collected. For deep groundwater sites, the well was purged for fifteen minutes. The production well samples were taken directly from a spigot attached to the pumping well. These samples were obtained from either Well 29 or Well 30 at the West Wellfield, depending upon which pump was in operation on the day of sampling. Surface water samples from the Everglades and canal sites were collected by immersing the scintillation vials below the water surface. At the lakes, a submersible pump was used to collect water from ten-foot depth intervals from the approximate center of each lake. Rainwater collection for isotope analysis provided a somewhat unique problem, as collected rainwater must be shielded from evaporation effects. In order to accomplish this, rainwater collection bottles were filled with a two inch deep layer of mineral oil prior to use. These bottles were fitted with a collection funnel and an air release port. As rain entered the collection apparatus, the buoyant mineral oil floated on top of the collected rain, preventing rainwater interaction with the air and insuring the isotopic integrity of the sample. Once the rainwater was collected, a syringe was used to transfer the rainwater from below the mineral oil layer into the scintillation vials. Sample Analysis Oxygen-18 analysis included a CO2 equilibration procedure utilizing a syringe as described by Matsui, 1980. This syringe technique was compared with the more traditional CO2 equilibration procedure (Epstein and Mayeda 1953) with good results (Standard deviation 0.18). Samples for deuterium determinations were processed using one of two methods. The first method utilized a uranium furnace as outlined by Bigeleisen et al.1952. The second method involved the use of a chromium furnace (Gehre et al. 1996). See Water-Resources Investigations Report 00-45066 for complete details of data collection and analysis. 2000 Helena Solo-Gabriele University of Miami Professor and Associate Dean for Research mailing address

Department of Civil, Arch., and Environmental Engineering P.O. Box 248294

Coral Gables FL 33124-0630 USA 305 284 2908 hmsolo@miami.edu Levee 31N Data collected for use in the model to estimate the seepage rates beneath Levee 31N included geologic data, vertical seepage measurements, surface-water stage and discharge measurements, and continuous ground-waterlevel readings. The data were used to define model boundary conditions and parameters and to calibrate the model WRIR 00-4066 20101206 Heather Henkel U.S. Geological Survey mailing and physical address

600 Fourth Street South

St. Petersburg FL 33701 USA 727 803-8747 ext 3028 727 803-2030 sofia-metadata@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 none This metadata record may have been copied from the SOFIA website and may not be the most recent version. Please check http://sofia.usgs.gov/metadata to be sure you have the most recent version.