St. Johns River at Mayport (in MHHW)

The past week

What floods at each level

• 3.3 ft

  Major Flooding - 3.3 feet above MHHW - Major Coastal Flooding. Coastal Flood Warning needed. Extensive inundation of structures and roads in the area is expected. Evacuations of people or transfer of property to higher ground is likely and the advice of Emergency Management should be heeded. Extensive beach erosion is possible and possible breaches of the dune line...especially in lower areas and beach access areas. Significant past events: 2 October 1898 Hurricane.

• 2.29 ft

  Moderate Flooding - 2.3 feet above MHHW - Significant Coastal Flooding begins and Coastal Flood Warning needed. Some flooding of structures and roads along the coast, St Johns River and other inland waterways is expected. Evacuation of people or property to higher ground is possible and the advice of Emergency Management or local officials should be heeded. Significant past events: Hurricane Dora 1964.

• 1.8 ft

  Minor Flooding - 1.8 feet above MHHW - Coastal Flood Advisory is likely and Coastal Flood Warning Possible if significant wind and wave action drives water levels higher along the immediate coast. Flooding of low lying roads and campgrounds possible. Water levels may surge up the dune lines and into beach access areas. Some boat ramps and docks near the St. Johns River entrance and other inland waterways may begin to flood. Significant past events: Tropical Storm Fay...Hurricane Jeanne and 11/23/1984.

• 1.3 ft

  Action Stage - 1.3 feet above MHHW - Coastal Flood Advisory is possible if significant wind and wave action drives water levels higher along the immediate coast. Should water levels continue rising...preparations to protect property should begin.

Highest crests on record

More on St. Johns River