Online tools, GIS, data
In this section
Watershed facts home
Map of watershed monitoring stations
Methodology
Technical background
Glossary
Metadata
Staff contacts
Watershed facts
Integrating environmental science and computer mapping technology

Cypress trees dot the western shoreline of the St. Johns River in Clay County.
If you live in northeast and east-central Florida, you live in a watershed monitored by the St. Johns River Water Management District. The District designed this section of its website to provide information about the health of the region’s watersheds.
A watershed is an area that water flows over before flowing into a body of water. This site uses Arc Hydro, a modern mapping and data-modeling technology, to deliver easily understandable information about water quality and watersheds in the District’s service area.
The link “map of watershed monitoring stations” will allow you to explore the 73 watersheds monitored by the District’s Surface Water Quality Monitoring (SWQM) program. See descriptions of each watershed and the water quality information the District collects, such as water acidity, clarity, dissolved oxygen and temperature. See how powerful geographic information system (GIS) mapping technology was used to put these measurements in the context of land use, population density, geology, rainfall, aquifer recharge and more.
The watersheds monitored by the SWQM program cover approximately 80 percent of the District’s 18-county area. Other monitoring programs operated by the District cover the remaining areas.
Resources
Arc Hydro is based on geographic information system (GIS) software, linking comprehensive maps with databases of information collected by the District and other agencies. Arc Hydro was developed by Dr. David Maidment (University of Texas, Austin — Center for Research for Water Resources), in collaboration with several prominent universities (Consortium of Universities for the Advancement of Hydrologic Sciences) and ESRI (Environmental Systems Research Institute), as a mapping software for water resource professionals. See GIS metadata.
Other links:


