California drought driving up greenhouse gas emissions: study

Drought in California, coupled with population growth, is accelerating the need for energy-intensive water projects — driving up greenhouse gas emissions and thwarting the pace of statewide decarbonization efforts, a new study has found. 

Water use, collection, treatment and management is linked to about 20 percent of California’s statewide electricity use, one-third of non-power-plant natural gas consumption and 88 billion gallons of diesel use, according to the study, published by the Oakland-based Pacific Institute and commissioned by the nonprofit think tank Next 10.

Up against formidable water challenges, urban water planners are opting to integrate new water supply technologies, like desalination and water recycling, the researchers observed. And while these supply choices usually require less energy than transporting water long distances, the authors said that these facilities do expend more energy than withdrawing from traditional resources, like reservoirs and aquifers.

“If you think about water and energy together, then some of the decisions we make will be different,” Peter Gleick, co-founder and president emeritus of the Pacific Institute, told The Hill. “Given the climate crisis, it’s important we make smarter decisions about both water and energy.”

Water and energy are “inextricably linked in California,” according to the authors, who stressed that the State Water Project — which pumps water from Northern California lengthy distances — is the single largest consumer of electricity in the state. Such interdependencies mean that “as one resource faces constraints or challenges, so does the other,” in a relationship known as the “water-energy nexus.”

Although declining groundwater levels have made pumping water more energy-intensive in the agricultural sector, the report found that escalating urban water demands are taking a greater toll on the state’s electricity usage — with urban water roughly twice as energy-intensive as agricultural water. 

As such, efforts to improve efficiency in urban water usage would have the biggest impact on California’s water-related greenhouse gas emissions, according to the authors. A failure to make such upgrades would lead to a 24 percent increase in urban water demand between 2015 and 2035, resulting in a 21 percent increase in annual water-related electricity use and a 25 percent increase in natural gas consumption, the study found.

“When we save water, we also save energy and reduce greenhouse gas emissions,” Julia Szinai, lead author of the report and a researcher at the Pacific Institute, said in a news release. “The importance of water conservation measures in meeting California’s climate targets should not be underestimated, especially as drought and water scarcity become more intense with climate change.”

So critical are these measures, according to the authors, that the implementation of comprehensive water conservation and efficiency strategies could facilitate a 19 percent reduction in water-related electricity usage between 2015 and 2035, a 16 percent reduction in natural gas usage and a 41 percent drop in greenhouse gas emissions.

“The good news here is the solutions that provide the best climate outcomes are almost always economically and environmentally the best solutions as well,” Gleick told The Hill. 

Some such solutions that the authors recommended include water heater electrification, which is the most energy-intensive end-use of water and still largely occurs through natural gas heaters today. 

They also advised installing higher efficiency groundwater pumps and providing financial incentives for water suppliers to invest in less energy-intensive systems. In addition, they suggested standardizing water data reporting and tracking related energy use, as well as formalizing the coordination between water and energy agencies. 

Another energy-intensive end use, wastewater treatment — which uses nearly 1 percent of the entire country’s electricity — could become cleaner by capturing gas from the decomposition of waste and using it to power the facility, the authors added. The East Bay Municipal Utility District’s treatment plant, for example, generates more renewable energy than is needed onsite, and therefore sells the surplus back to the grid. 

If energy-intensive technologies like water recycling or desalination are to remain part of a region’s water supply landscape, officials must work on decarbonizing the grid — with the ultimate goal of “changing the energy system itself” alongside strong conservation policies, according to Gleick.  

“Almost everywhere around the country smarter conservation and efficiency is by far the best option to pursue,” he said. “Every gallon of hot water you don’t have to use because your washing machine or dishwasher is more efficient is a gallon of water you don’t have to provide and energy you don’t have to provide.”