Expert Offers Insight on Restoring Groundwater Reserves Following Prolonged Drought

Newswise — Despite recent rains, a West Virginia University physical hydrology professor cautions that substantial rainfall will still be needed to “recharge” groundwater supply across the state and help the ecosystems return to normal after an abnormally hot and dry summer.

Jason Hubbart, interim associate dean for research in the WVU Division for Land-Grant Engagement, associate director of the West Virginia Agricultural and Forestry Experiment Station and professor of physical hydrology in the Davis College of Agriculture and Natural Resources, outlines how much the groundwater reserves differ across the state’s landscape and the factors that affect how quickly those can be rebuilt.

However, Hubbart notes there is one factor that seems to be working in our favor right now — cooling fall temperatures.

Quotes:

“As you might expect, water and ecosystem response to drought can vary substantially, even within a small area. Recovery times following prolonged drought for forests, plants and animal populations, all of which depend on water to survive, can depend on several highly variable factors, such as the depth and size of the underground water aquifer, soil types and the rate that water can get back in the soil, runoff rates, hillslope angle, land use practices, etc.”

“Estimated rainfall needs to ‘normalize’ conditions back to long-term average conditions also can vary spatially. Under normal circumstances, groundwater recharge rates can vary from less than 1% to over 20% of annual precipitation, depending on local conditions. For example, during drought conditions, if an aquifer deficit is estimated at 10 inches, and local recharge rates are 10% of annual rainfall, it would require approximately 100 inches of rain to recharge the aquifer fully. Aquifers, which include shallow and deeper groundwater, can vary significantly over very short distances in Appalachia. Knowing the current conditions due to the drought in West Virginia in 2024 is complex, given how much the landscape attributes vary.”

“In general, West Virginia needs sustained rainfall. A single rainfall event is less effective than a consistent, moderate precipitation over time. We need more of the smaller, longer-lasting events, so that soil infiltration rates can soak up a greater proportion of the rainfall, rather than the rain running off the surface.”

“Some good news is that we’re rolling into the cooler months of the year, so rainfall that we do get will not evaporate as quickly, surface soils will remain wet longer and we should see higher infiltration rates, thereby more quickly recharging shallow and deeper groundwater supplies.” — Jason Hubbart, professor of physical hydrology, WVU Davis College of Agriculture and Natural Resources, interim associate dean for research, WVU Division for Land-Grant Engagement, and associate director, West Virginia Agricultural and Forestry Experiment Station