Hurricane Ian’s effects on our water levels

October 19, 2022

Using publicly available data from the South Florida Water Management District, United States Geologic Survey, and the National Hurricane Center, Dr. Paul Julian, hydrologic modeler for the Conservancy and Sanibel Captiva Conservation Foundation, created this animation to demonstrate the effect of Hurricane Ian on water levels in our local rivers and the Naples Pier.

While Hurricane Ian was a very large storm with an eyewall measuring 34 miles in width (55 kilometers; source), the map visualization shows Hurricane Ian’s approximate center line and progression (dots) across the state as it made landfall. The graphs on the right show the change in water levels before, during, and after the storm passed, from September 24th to October 1st.

The influx of Ian’s storm surge at high tide resulted in water level changes by eight feet at the Franklin Lock (S-79) in the Caloosahatchee River, approximately seven feet for the Gordon River, and eight feet for the Cocohatchee River. In the case of the Imperial River in Bonita Springs, the surge in water levels remained relatively high for days after the storm due to rainfall runoff associated with the drainage of the larger watershed.

For most of the rivers, before the storm, there are notable waves (i.e., oscillations) in the data, which is the result of the normal tidal cycle. As Ian approached our coast, water levels receded rapidly (drawing out of water) followed by a surge (spike) in water levels as the water was pushed by the storm (i.e., storm surge) up the rivers.

Note: Naples Pier, Henderson Creek, and Barron River locations either have data gaps or missing data after the storm has passed due to power loss or damage to the infrastructure.