GROUNDWATER

"There are many reasons why groundwater is essential to health and the well-being of humanity and the environment. When people talk about climate change and impacts to water resources, they tend to focus on things like drought, flooding, drying up surface water bodies and melting glaciers. However, the potential for groundwater to be threatened or be a conduit for climate change impacts is also a concern.

An obvious concern is depletion of groundwater as it becomes an increasingly important water source. As precipitation becomes less reliable due to climate change, surface water bodies can drop too low to provide needed water, causing people to turn to groundwater sources. Over-pumping and depletion of groundwater is already a significant problem in many places across the Eastern Region. Over-pumping will increase as climate change makes traditional sources of water less reliable. Less obvious are ways in which groundwater may be a conduit of climate change impacts. For example, recent research based on modeling found the eastern United States is particularly vulnerable to increasing evapotranspiration, which decreases shallow water tables.

Evapotranspiration is a combination of evaporation and transpiration, which refers to the water that plants release to the air. While a permanent water table decrease of one to three feet may not mean anything for a water supply well, it can have severe consequences for surface water bodies and ecosystems dependent on that shallow water table.

Other research has shown that groundwater could lead to warmer surface water bodies, such as streams. Many cold-water streams in the region depend on groundwater to maintain their cold-water conditions, which are required by many organisms. This water originates as precipitation that infiltrates into the ground as recharge and eventually becomes groundwater discharge (baseflow) to water bodies. The research has found that warmer precipitation and recharge will eventually reach streams and rivers as warmer baseflow. This may take a few decades, which can make planning for these streams even more challenging."

Five takeaways from a recent New York Times investigation - 

• Aquifer water levels are falling nationwide. The danger is worse and more widespread than many people realize.
• We know this because we built a database of more than 80,000 wells nationwide.
• Overpumping is a threat to America’s status as a food superpower.
• It’s not just a problem in the West or for farmers. It’s a tap water crisis, too.
• Weak regulations allowed the overuse. Now, climate change is leading to even more pumping.