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Everglades Depth Estimation Network (EDEN) for Support of Biological and Ecological Assessments
- Explanation of Terms and Methods
Photo of a pond

Explanations of Terms and Methods (for Water-Level Values)

Operating Agency:
BCNP Big Cypress National Preserve
ENP Everglades National Park
SFWMD South Florida Water Mangement District
USGS U.S. Geological Survey
EDEN Station Name:
The station name used in the site is specific to the EDEN site. It generally is the same name as the agency station name, but there could be slight variations (either this is a shortened form, or a modified form). For example:
  • EDEN name: 3A9; Station name used by operating agency: 3A9+
  • EDEN name: 3AN1W1; Station name used by operating agency: 3AN1W1+
Location Area:
Area of Everglades where gage is located (gages along canals are reported by the canal name, gages across canals are reported by what area the headwater or tailwater gage measures)
Marsh Stations Choices: Canal Stations Choices: Coastal Stations Choices:
BCNP Hillsboro Canal Coast of Florida Bay
ENP Tamiami Canal Coast of Gulf of Mexico
WCA1 L-40
WCA2A etc.
Pennsuco Wetlands
Data Links:
Available Parameters List of data parameters stored in the EDEN database; data for graphing and downloading available using Explore and View EDEN (EVE) webpage.
Daily Water Level Percentiles Link to daily water-level percentile plot used to monitor water level during the Everglades Restoration Transition Plan (ERTP) period. Data also used to compare water levels during the ERTP period with water levels that occurred during the Interim Operational Plan (IOP) period.
Operating Agency Link (if available)

Link to the operating agency for the original source data, full period of record (POR) for the gage, and other parameter datasets, if available. Note that Everglades National Park (ENP) has no public web access to their database.

Point of contact for operating agencies:

Datum Information:
Why are all gage data not referenced to the same datum?

Prior to 1991, all water gages were surveyed to the National Geodetic Vertical Datum of 1929 (NGVD29) in Florida, a vertical reference from which Elevations can be measured to provide relative differences between water levels at gages. In 1991, the North American Vertical Datum of 1988 (NAVD88) was established and some gages were referenced from this new vertical reference. In south Florida, the difference between elevations referenced in NGVD29 and elevations referenced to NAVD88 are between 1 and 2 feet depending on the location. (See for more information about vertical datums.)

Data for many gages in the EDEN network are referenced to NGVD29 by the operating agencies. When posted to EDENweb, they have been converted to NAVD88 using the conversion value documented on the station information page. Some gages operated by the USGS have not yet been converted to NAVD88.

Users are advised to note the datum of all datasets to avoid using or comparing data with different datums.

How do I convert data at a gage from one datum to another?

The Station Information page for each gage on EDENweb provides the value to convert data at the gage from NGVD29 to NAVD88:

  • For data in NGVD29, ADD the conversion value
  • For data in NAVD88, SUBTRACT the conversion value

For example: Site 69:

  • On 01/16/07 at 12:00, gage height = 8.63 ft. NGVD29
  • To convert to NAVD88: 8.63 + (-1.66) = 6.97 ft. NAVD88

For example: Site L28_GAP:

  • On 01/21/07 at 01:00, gage height = 10.22 ft. NAVD88
  • To convert to NGVD29: 10.22 - (-1.42) = 11.64 ft. NAVD88
How were the vertical conversions at gages determined by EDEN?

The operating agencies provided the vertical conversions at most gages. For gages only surveyed to NAVD88, the datum conversion was estimated using the CORPSCON 6.0 for VERTCON version 2.5 grid modified by the USACE Jacksonville District to incorporate the CERP vertical control network established in 2001-2002 (Rory Sutton, USACE).

More information about CORPSCON 6.0:

Ground Elevation and Vegetation Information:

Water levels (i.e., water stage) at each gage station are measured relative to a vertical datum, but ground elevation at each gage station is not usually surveyed. Because many scientists use water depth instead of water levels, EDEN provides estimates of ground elevation at each gage. All ground elevation values were estimated relative to the gage station’s water level measurements.

thumbnail of line drawing showing methodology for obtaining water depths

First, water depth was measured at a minimum of six locations in the major vegetation community surrounding the gage station. Then, ground elevation was calculated by subtracting the water depth from the water level reading at the gage. Last, all six ground elevation estimates were averaged. If the area surrounding the gage was dry, the same steps were performed but by optically estimating ground level relative to the gage water level reading.

More detail can be found here.

Note that these ground elevation estimates are not used in the DEM (digital elevation model) which is used to create the interpolated water depth surfaces.

Vegetation Community:

Vegetation community at the gage, field descriptions are categorized into major communities for freshwater and tidal gages.

Choices for freshwater gages:

  • Slough or open water
  • Wet prairie
  • Ridge or sawgrass and emergent marsh
  • Exotics and cattail
  • Upland
  • Canal (gage constructed in a canal along a levee or in the marsh but not at a canal structure)
  • Other (mostly wetland shrub and wetland forested)

Choices for tidal gages:

  • Marsh
  • Upland
  • Forest
  • Open water (river, canal, bay, etc.)
Type of Station:

Physical Location: Canal and marsh indicate stations located in uncontrolled regions, canal structure indicates a station located within a canal at a structure, usually with an associated station on the other side of the structure, marsh structure indicates a station located in the marsh at a structure, usually with an associated station on the other side of the structure. In both cases, the associated station does not have to be of the same type (canal or marsh). Values:

  • Canal
  • Canal structure
  • Marsh
  • Marsh structure
  • River
  • Forest

Water: There are only two options for this value:

  • Freshwater
  • Tidal
Technical support for this Web site is provided by the U.S. Geological Survey
This page is:
Comments and suggestions? Contact: Bryan McCloskey
Last updated: December 01, 2023 05:47 PM (BJM)