How Amazon is Helping Keep a River Flowing in Northern California

The Cosumnes River, a gold-rich river that runs through a diverse range of California terrain, was once a hotspot for miners in search of wealth during the 1800s. The glitter of the gold rush subsided long ago, and in recent years, years of drought have caused stretches of the Cosumnes to run dry. The river is critical to farmers, wildlife, and a huge portion of the state’s population. It contributes to the San Francisco Bay and Sacramento–San Joaquin River Delta Estuary (Bay Delta), the largest natural estuary on the western coast of North and South America.

Amazon Web Services (AWS), the cloud computing subsidiary of Amazon, is committed to ensuring that it has a positive impact on water resources in Northern California and other regions where it operates. AWS is committed to being water positive by 2030, which means that it will return more water to communities and the environment than it uses in its direct operations. One way AWS will meet this goal is by investing in water replenishment projects in the communities where it operates.

In Northern California, AWS is replenishing water by recharging groundwater along the Cosumnes River in partnership with The Freshwater Trust and the Omochumne-Hartnell Water District. Decades of excessive groundwater use along the Cosumnes have contributed to diminishing surface water levels, which is raising concerns for wildlife, farmers, and the surrounding communities. Replenishing groundwater increases its supply, which in turn increases surface water levels in the Cosumnes River.

To recharge groundwater, the Omochumne-Hartnell Water District is applying excess water from winter storms to two vineyards adjacent to the Cosumnes in the winter months. The absorption of the water into the underlying groundwater reservoir will help the local deficit and contribute to surface water flow during drier summer and fall months. It may also lower the temperature of the river, improve wildlife habitat, and increase the amount of water deposited into the Bay-Delta, helping to decrease the risk that California communities and farmers will have to do without water from this critical source.

“The Cosumnes River is one of only a few undammed rivers left in the state of California, and its natural flow regime is absolutely critical to the ecological and human communities in the region,” said Erin Donley Marineau, Ph.D. and California programs director at The Freshwater Trust, a conservation non-profit. “When we take steps like these to improve groundwater replenishment, it’s good for the environment and humans.

“This particular project provides an example of the type of work that can be scaled to many different locations,” said Marineau. “And if it is done at scale, it can have a very large impact.”

AWS is committed to collaborating with employees, global nonprofits, local communities, and public utilities to create new solutions that will help achieve its water positive goal. By doing so, AWS is creating a better future for the planet.

“At AWS, we are committed to ensuring we have a positive impact on water resources in Northern California and other regions where we operate,” said Will Hewes, AWS Water Sustainability Lead. “While we rely on water from the Bay Delta to cool some of our Northern California data centers, we are also working with local governments, public utilities, and nonprofits to recharge groundwater and invest in recycled water infrastructure to help solve water challenges in the region.”