Throughout the next few weeks, water levels in the St. Johns River will continue to fluctuate as flood waters from Hurricane Ian drain into the river. Parts of the river were still cresting this week, causing additional flooding concerns for central Florida, especially in Seminole County.

The St. Johns River Water Management District’s flood protection mission can be thought of in three parts. The District preserves the floodplains of rivers and lakes. These undeveloped wetlands can safely store floodwaters. Secondly, the District has a structural water management system, based on levees and water control structures in the Upper St. Johns and Ocklawaha rivers. Finally, we collect and share real-time data on water levels with the U.S. Geological Survey, which the National Weather Service uses for its flood predictions.

The District only provides flood control in two specific areas: the Upper St. Johns River Basin and the Upper Ocklawaha River Basin. The District does not directly control water elevations in areas downstream of these flood control areas. For example, the combination of federal and District projects’ benefits do not reduce flooding in east-central Florida (the St. Johns River’s middle basin), nor further downstream in the St. Johns River’s lower basin in north Florida. This is because prior to the St. Johns River reaching central and northern Florida, the many tributaries to the St. Johns contribute to the river’s flows (see map of our flood control areas).

For Hurricane Ian, the District did not open structures S-96 and S-157 in the Upper St. Johns River Basin, which would have discharged water to the St. Sebastian River through the C-54 canal. Trigger water levels to open those structures were not reached during this event.

Hurricane Ian brought between 14 and 18 inches of rain to central Florida, and that much water in such a short time overwhelmed the natural wetlands systems. It could take several weeks for these water levels to drop. Residents are encouraged to stay vigilant and monitor the weather and river levels in their area. Current river levels can be found on our website at www.sjrwmd.com.

Helpful links

Flooding — During a storm, if you are in immediate danger of flooding, please call 911. Less urgent flooding concerns and emergency response during and after storms is managed by county emergency operations centers in coordination with local governments and state emergency management officials. The District assists with efforts when receiving requests coordinated through the state Emergency Operations Center.

• Orange County Emergency Management (orangecountyfl.net)
• Osceola County Emergency Management (osceola.org)
• Seminole County Emergency Management (seminolecountyfl.gov)
• Volusia County Emergency Management (volusia.org)
• Flagler County Emergency Management (flaglercounty.gov)

Rainfall and flood stages — Hydrologic data is available on the District’s website and we provide links to other entities with helpful information.

• Radar rainfall
• Daily rain bar chart
• Controlled water level reports

National Weather Service

• River observations, forecasts and flood stage indicators

Other helpful information about the District’s flood protection work and storm resources can be found year-round on our website at www.sjrwmd.com/storm.