Growing up on the coast of Maine, Will Hewes spent summers sailing, swimming, and kayaking. Water was at the core of his childhood. Fast forward to today. Hewes still lives in Maine, and when he’s not building boats, he’s working to find solutions to the world’s water challenges. As the water sustainability lead at Amazon Web Services (AWS), Hewes’ job is to ensure that the company is using water responsibly while also helping to increase water availability in the communities where AWS operates.
“When I discovered in my adult life that water was an issue that was overlooked and undervalued, it was a natural fit for me to want to work on it,” Hewes said while on the shore of the Puget Sound during a visit to Amazon’s headquarters in Seattle, Washington.
A photo AWS Water Sustainability Lead Will Hewes standing next to a wooden canoe in a garage.
On one of the smokiest days the Seattle area has ever seen due to fires in eastern Washington—a sign of our planet’s environmental state—Hewes detailed the growing challenges facing our supply and consumption of water. A myriad factors—including climate change, aging infrastructure, and pollution—have combined in a way that is making water increasingly scarce. We see the effects in the shrinking water levels in rivers and lakes across the globe, as well as the duration and severity of drought conditions on the planet. According to the United Nations, by 2025, 50% of the world’s population is projected to live in water-stressed areas, with low-income families bearing the greatest brunt of this crisis. But despite the hard reality of the data, Hewes shared some good news.
“I'm hopeful because we're seeing more innovation in the water sector than we've ever seen before,” said Hewes. “We're seeing new technologies, new financing models, and new business models that can fundamentally change how we address these water challenges.”
For AWS operations, water is an essential resource. It’s primarily used for cooling data centers around the world. And while the company needs water, Hewes says AWS can do its part in solving the water crisis.
Over the past two years, Hewes has been spearheading projects that reduce the amount of water AWS uses and increase the amount of water AWS returns. All these projects are contributing to AWS’s commitment to be water positive by 2030. Being water positive means AWS will return more water to communities than it uses in direct operations. The four pillars of AWS’s water-positive commitment are efficiency, recycling, reuse, and replenishment. AWS is partnering with global nonprofits to replenish water-stressed areas and return water to the communities where it operates. But a big part of getting to water positive starts with AWS’s data centers, where the company is working to improve water use efficiency and increase the use of sustainable water sources.

Engineering systems that reduce water use

A photo of mechanical pipes in a data cooling system.
As a principal mechanical engineer, Suresh Soundararaj’s job is to design the efficient cooling systems for AWS data centers. He says that in an ideal world, AWS wouldn’t use any water at all, but water is a crucial tool for cooling.
“An AWS data center is a labyrinth of servers, routers, and networking cables, and all this hardware gets pretty hot, so we need to cool it,” said Soundararaj. “One of the ways we do this is with water.”
The preferred cooling strategy for AWS data centers uses evaporative technologies. In this system, hot air is pulled from outside and pushed through water-soaked cooling pads. The water evaporates and cools the temperature of the air sent to the server rooms. In effect, this is a more sophisticated (and much larger) version of a residential “swamp cooler.”
A GIF of an illustration of Direct Evaporative Cooling
To fine-tune the cooling operation and reduce water use, AWS also devised a “free-air cooling” system. AWS installed sensors that track weather parameters like temperature and humidity. As soon as the conditions drop to a safe operating range, the evaporative cooling system shuts off, and cool air from outside is sent to the server rooms. In Ireland and Sweden, AWS uses no water to cool its data centers for 95% of the year and instead uses free-air cooling.
A GIF of an illustration explaining Free-Air Cooling
AWS also invests in on-site water-treatment systems that remove scale-forming minerals and allow AWS to recycle more water on-site and minimize the water consumed for cooling. To further improve water efficiency, AWS uses real-time water use data to identify leaks, pilot new treatment technologies, and explore a range of operational changes.

Tapping into sustainable water sources

A photo of an outdoor sign that states, "Irrigated with recylcled water, Do Not Drink, No Beber".
At AWS’s data centers in Santa Clara, California, switching from the existing cooling system to a direct evaporative cooling system reduced annual water use by 85%. Given the state’s severe water scarcity challenges, every drop saved makes a difference, which is why AWS is reducing water use and changing the type of water used for cooling. The Santa Clara data centers are among the many AWS data centers that use recycled water or reclaimed wastewater for cooling, instead of potable or drinkable water.
“Water conservation is a two-way street. It takes action from all aspects of our community. That’s why it is so important to have partnerships with customers like AWS that are committed to finding ways to use recycled water in their operations,” said Shilpa Mehta the assistant director of Water and Sewer Utilities for the City of Santa Clara.
Recycled water is typically used for irrigating public parks and golf courses or cleaning city sidewalks, but the high quality of Santa Clara’s recycled water makes it safe and effective for cooling systems. The wastewater undergoes a three-step treatment process that removes 99% of impurities. This process makes it the highest quality recycled water in California. After the recycled water runs through the cooling system, it returns to the wastewater facility for another round of treatment so it can be used again.
“Recycled water is a sustainable source of water, and it offsets our precious potable water,” said Mehta. “Reusing it saves our city’s potable water for the places and people that need it most.”

Sending spent data center cooling water to neighboring farms

A photo of an irrigation canal that runs through Umatilla, Oregon, delivering spent data center cooling water to AWS data farms.An Irrigation canal that runs through Umatilla, Oregon, delivering spent data center cooling water to local farms. Credit: Noah Berger
For over three decades, Vern Fredrickson has been growing wheat in eastern Oregon. Many farmers in the region rely on water pulled directly from the Columbia River to irrigate their crops, but Fredrickson gets his water from an unlikely source.
“Besides the land we own, water is one of our greatest assets,” said Fredrickson, who is also vice chair of the Board of Directors for the West Extension Irrigation District in Oregon. “Every gallon is important to the community, especially for farmers like me.”
Fredrickson now gets his irrigation water from nearby AWS data centers. Five years ago, AWS and Umatilla community leaders worked together to develop a sustainable solution to recycle the water used to cool AWS data centers. The plan led to local municipalities and AWS investing in miles of new pipeline, allowing up to 96% of all spent cooling water from the nearby data centers to be reused in local communities.
Before the water is delivered to farmers and used for cooling, AWS treats the water on-site, so it can be reused up to four times. This makes the water safe enough for cooling and irrigation. AWS also installed sensors to continuously monitor water quality, a step that Kelly Galway, a water resource data manager overseeing the program, says adds more surety that the water is ready for crops.
“The sensors collect data, and AWS IoT gateways transmit the data to the cloud for analysis and automated alarming,” said Galway. “If there are any water quality issues, we’re instantly alerted.”
This system leverages the power of the AWS Cloud, offering a secure solution to collect data and scale the program easily going forward.

Returning water to communities

A photo of six girls in Chittoor, India standing in line at an outdoor hand-washing stationA hand-washing station at the Zilla Parishad High School set up by WaterAid. Credit: WaterAid India/Narayana Swamy Subbaraman
At the Zilla Parishad High School in Chittoor, India roughly 500 students and teachers line up at the hand-washing station each day. The water comes from a 2,500-liter storage tank that was constructed by WaterAid with support from AWS. This is one of the several AWS-funded replenishment projects in India. These projects with nonprofits like WaterAid and have increased access to safe water for nearly 300,000 people in India and Indonesia.
“Our collaboration with Amazon and AWS already brings over 805 million liters of safe water to communities around the world every year, and we are excited to continue to work with Amazon to bring even more safe water to families in need,” said Gary White, CEO and co-founder.
Matt Damon, co-founder, added that the nonprofit’s work with AWS is supported by the shared belief that solving the global water crisis is possible. Replenishment projects are a huge part of this effort. In addition to bringing safe water, sanitation, and hygiene services to water-stressed communities, AWS is also investing in projects that restore watersheds around the world.
A photo of AWS CEO Adam Selipsky with co-founders Matt Damon and Gary White on stage in a panel format at Climate Week NYC 2022.AWS CEO Adam Selipsky talks water replenishment with co-founders Matt Damon and Gary White during Climate Week NYC 2022.
Similarly, AWS partnered with The Nature Conservancy to restore over 350 hectares of land in the watersheds serving São Paulo, Brazil, and Cape Town, South Africa. These projects are helping to improve water quality and availability to surrounding communities.
In the United Kingdom, AWS is working with The Rivers Trust and local member trust Action for the River Kennet to create two wetlands on a tributary of the River Thames. The wetlands will recharge nearly 600 million liters of groundwater per year and improve water quality by receiving and treating polluted runoff from farms and roadways. This project will help address growing water scarcity and water quality in the Thames River basin.
“We are looking forward to growing our relationship with AWS and using this partnership to demonstrate a similar path other businesses can take to support collaborative water stewardship activities that improve the resilience of our rivers,” said Mark Lloyd, CEO of The Rivers Trust.
As AWS works towards a water-positive future, it will continue collaborations with charities and nonprofits that share the same goals. So far, AWS-funded replenishment projects have returned nearly 2.4 billion liters of water to communities and the environment, and this is just the start. AWS is also working to reach net-zero carbon emissions by 2040 as part of The Climate Pledge, which Amazon committed to in 2019.
More information about AWS’s water-positive commitment can be found on Amazon’s Water Stewardship website.