Lack of rain­fall had a sil­ver lin­ing

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

Los Angeles Times - - CALIFORNIA - 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.

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