You might think it takes a lot of rain to cause river flooding, but in Astor, strong winds can make a big difference. In recent days, the St. Johns River has been rising because persistent northeast winds pushing water upstream and slowing its flow toward the Atlantic ocean.

How can wind make a river flood?

The St. Johns River is quite unique in that it’s one of the very few rivers that flow northward, eventually emptying into the Atlantic Ocean near Jacksonville.

But when strong northeast winds blow across the water, it pushes ocean water back into the mouth of the river, preventing its slow flow northward.

A slight uptick in northeast winds plays a big role in the flow of the St. Johns because the river is naturally very flat and very slow-moving.

So when the wind pushes water upstream, it takes longer for that water to drain away. This backup causes water levels to rise and flow into nearby yards, docks, canals and roadways.

What’s happening right now?

Persistent, gusty northeast winds have been slowing the river’s flow and causing water levels near Astor to rise. Moderate flooding is occurring, and water levels are expected to gradually decline as conditions improve.

Even after the winds ease, the water won’t disappear overnight. Because the river flows so slowly, it can take time for levels to fall back below flood stage.

For people living near the river, that means flooding will be likely through the weekend.