Los Angeles Times

Lack of rainfall had a silver lining

Research shows water conservati­on led to reduced energy use and less pollution.

- DEBORAH NETBURN deborah.netburn @latimes.com Twitter: @DeborahNet­burn

In April 2015, Gov. Jerry Brown called on the people of the most populous state to reduce their water use by 25% in response to a punishing four-year drought.

It was an audacious goal, and California­ns came close to meeting it. From June 2015 to April 2016, when restrictio­ns were in effect, residents reduced the amount of water they used by 24.5%.

Now, research has revealed there were some unintended side effects to this massive water-conservati­on experiment. It turns out that California residents weren’t just saving water, they were saving energy as well. A lot of it. In a new report published in Environmen­tal Research Letters, a team from UC Davis found that in addition to saving 524,000 million gallons of water over the mandate period, state residents saved 1830 gigawatt hours of electricit­y — enough to power 274,000 average homes for a year.

That electricit­y savings meant a reduction of 521,000 metric tons of greenhouse gases, the equivalent of taking about 110,000 cars off the road for a year, the authors wrote.

“The severity of this drought created a unique circumstan­ce that allowed us to make a natural experiment,” said Edward Spang, associate director of the Center for Water-Energy Efficiency at UC Davis and the first author on the report. “We wanted to demonstrat­e that there were additional benefits to all the hard work that everyone did to save water.”

So, how did all these savings come to be?

California has what Spang describes as “energyinte­nsive water.” The amount of energy required to extract the water we use, treat it and distribute it varies depending on where in California you live, but overall, it is quite high.

“We have one of the largest-scale conveyance systems in the country,” Spang said. “Part of that is because of our geography. We have a lot more water in the north and a lot more people in the south.”

Spang and his colleagues cite previous work that found that roughly 19% of California’s electricit­y demand is related to the pumping, conveying, distributi­ng, heating and treatment of water. So when residents use less water, the state uses less electricit­y.

The authors also report that all the electricit­y and greenhouse gas emissions we saved when we thought we were saving only water is comparable to the results of statewide energy-efficiency programs that encourage people to change out lightbulbs and update appliances.

“The scale of these integrated water-energy-greenhouse gas savings, achieved over such a short period, is remarkable,” said Frank Loge, a co-author of the work and a professor of environmen­tal engineerin­g at UC Davis. “Even more interestin­g is that the cost of achieving these savings through water conservati­on was competitiv­e with existing programs that specifical­ly target electricit­y or greenhouse gas reductions.”

This led researcher­s to conclude that water conservati­on should be included in the state’s slate of initiative­s to reduce overall energy consumptio­n.

“There is quite a bit of valuable energy savings here,” Spang said.

 ?? Brian van der Brug Los Angeles Times ?? L.A. ECO-VILLAGE’S garden is irrigated with gray water in 2015. Residents weren’t just saving water during the drought; they were saving energy as well.
Brian van der Brug Los Angeles Times L.A. ECO-VILLAGE’S garden is irrigated with gray water in 2015. Residents weren’t just saving water during the drought; they were saving energy as well.

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