On this World Water Day, thank glaciers for giving us the Chesapeake we love

Every year on March 22, the world comes together to celebrate one thing we all have in common–regardless of where we live or if we are humans, plants or animals. It is the fact that we all need clean water for our survival. 

The United Nations formally recognized March 22 as World Water Day in 1992. Countries around the world are encouraged to acknowledge the importance of water in supporting ecosystems, as a critical component for sustaining all living organisms and as a necessity for agriculture, food production, human health and sanitation. 

As part of the celebration, the United Nations assigns a theme for each year, to further showcase all the ways that water is essential. In 2025, that theme is glacier preservation. Alright, I know you are scratching your heads and thinking, "Why would I care about preserving glaciers when there are none to be found in the Chesapeake Bay watershed?" It’s true, there aren’t any glaciers currently to be found in the Bay region, but oh, you are mistaken if you didn’t think glaciers had any role within the Chesapeake. 

It all started back in the Eocene Epoch, a mere 35 million years ago. A bolide, or very bright meteor, came streaming through the atmosphere from outer space, hitting what is now the lower portion of the Delmarva Peninsula, forming a 55-mile wide crater. Existing waterways began to flow toward the crater, gradually beginning to form the shape and size of today’s Chesapeake Bay.

Fast-forwarding about 25 million years later, ice begins to form across the world, covering the oceans with massive glaciers–a period more commonly known as the Ice Age. This period lasted millions of years until the climate began to slowly warm up (scientists believe the climate warmed due to the shifting orientation of the Earth toward the sun). Around 18,000 years ago, the glaciers began to melt.

Today’s present-day Susquehanna River watershed became flooded, carving a valley throughout Pennsylvania and creating a 400-foot deep canyon for glacial water to flow into the Chesapeake Bay. Over time, sediment filled in the canyon, creating the Atlantic Coastal Plain. 

Glaciers continued to melt, pouring water into the Atlantic Ocean, with flooding and erosion carving out other important Chesapeake Bay tributaries, like the James, Potomac and York rivers. These actions caused the land and water to continue to mold the Chesapeake into the shape it resembles today, approximately 3,000 years ago. 

Thirty-five million years ago, we were fortunate to end up with the Chesapeake Bay that we all know and love today. But in today’s world, glaciers are melting faster than what our scientists ever believed to be possible. We can help slow down this cycle by taking actions in our daily lives to help mitigate and adapt to changing environmental conditions. Using public transportation, lowering your thermostat in the winter and raising it in the summer, planting trees and switching to natural fertilizers are just some of the ways in which you can help ensure the Chesapeake Bay as we know it today sticks around for a few more million years.