Weather Explainers

Weather Words: Lakeshore Flooding

Lakeshore flooding happens when strong winds and waves push water toward the shoreline, causing rapid rises in water levels and damaging coastal areas along lakes.

During tropical systems, we talk a lot about coastal flooding. However, lakeshore flooding doesn’t need a tropical system and can be just as damaging.

Lakeshore flooding occurs when water levels rise high enough to inundate land along the edges of lakes, often flooding roads, homes, parks and marinas. Unlike river flooding, which is typically driven by rainfall upstream, lakeshore flooding is frequently caused by strong winds and rapid changes in water levels that push water toward one end of a lake.

On the Great Lakes, powerful and persistent winds can force water to pile up along the downwind shoreline, dramatically raising local water levels. Large waves riding on top of that elevated water can then crash over seawalls and beaches, sending water far inland. Seiches can worsen the situation by causing water to slosh back and forth across a lake, prolonging flooding even after the strongest winds begin to ease.

This image shows lakeshore flooding around Chicago.
(NOAA)

Lakeshore flooding can be especially damaging because it often develops quickly and is driven by both rising water and pounding waves. Erosion, damaged docks, flooded basements and impassable lakeside roads are common impacts.

Cold-season lakeshore flooding can be even more hazardous, as freezing spray, ice buildup and slick conditions complicate response and cleanup efforts, making these events both dangerous and destructive for shoreline communities.

Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.