Imagine celebrating the Fourth of July while scientists are knee-deep in a muddy river delta in the New Mexican desert! That's exactly what happened in 2021 when researchers Abby Eckland, Irina Overeem, and Brandee Carlson encountered a surprise flash flood in the Rio Grande, which had dwindled down to just a few channels due to years of drought.

But instead of fleeing, these scientists embraced the chaos! As the floodwaters rose, they seized the moment to gather crucial water samples and check their sensing equipment, uncovering an unexpected opportunity to explore a natural phenomenon.

The Incredible Discovery: Reservoirs as Carbon Sinks!

Fast forward to this month: their groundbreaking study published in Water Resources Research reveals a startling finding—reservoirs like Elephant Butte may act as powerful carbon sinks! During periods of drought and flash floods, these water bodies can trap organic carbon in sediment, preventing it from transforming into carbon dioxide.

How does this happen? The study explains a fascinating physics phenomenon: Normally, water spreads out when it enters a reservoir, but during high sediment flow, a powerful underwater current rushes downwards, creating what scientists call a "hyperpycnal plume." This plume forces organic materials to settle at the bottom of the reservoir.

Droughts and Flash Floods: A Perfect Carbon-Burying Recipe!

Armed with collected samples, the research team dove into lab tests, comparing their findings with historical data from the U.S. Bureau of Reclamation, thanks to Eckland’s invaluable connections with the agency. Their analysis revealed that not only is organic carbon getting buried beneath layers of sediment, but this burial significantly increases during droughts—less water means more carbon gets trapped!

And let's not forget the role of flash floods! As they surge through the landscape, they effortlessly pick up organic material, which subsequently ends up buried under the reservoir's sediment. This study uniquely pinpoints how the hyperpycnal plume facilitates this carbon delivery.

The Next Chapter: Confirming and Expanding the Research!

With this revelation, the team is eager to delve deeper. Overeem has returned to the reservoir site alongside new collaborators to gather even more samples. Early results show promising signs of higher organic carbon levels than initially estimated—a thrilling prospect for water management!

As these researchers illuminate the hidden benefits of dryland reservoirs, their findings hold the potential to revolutionize how we understand these infrastructures in relation to climate change. Who knew these desert waters could play a role in capturing greenhouse gases? Stay tuned!