Can California Make It Rain With Drones?

Faced with extreme drought, California continues its experiment with weather modification.

California Drought
National Journal
Brian Resnick
Add to Briefcase
Brian Resnick
Oct. 7, 2014, 7:46 a.m.

Bil­lowy and filled with life-sus­tain­ing wa­ter va­por, the cloud passes over­head without emit­ting a drop of rain. In times of severe drought, that cloud is a frus­trat­ing, lum­ber­ing tease. That cloud is tan­tal­iz­ing. De­li­cious even. 

What that cloud needs is a kick start, a cata­lyst to squeeze the wa­ter out of it. It’s not sci­ence fic­tion; it’s called cloud-seed­ing. And in bey­ond-parched Cali­for­nia, it may be­come a vi­able op­tion to com­bat long-term wa­ter short­ages.

Cloud-seed­ers can’t make rain ap­pear out of clear blue sky. Rather, they cre­ate snow (and some­times rain) where it’s most likely to oc­cur — in clouds. Yes, that cloud is full of wa­ter va­por, but some­times, wa­ter needs to be coaxed in­to form­ing the ice crys­tals needed for snow (you can see this hap­pen­ing in this video). The seed­ing devices, which are mainly on the ground, burn sil­ver iod­ide in­to a fine mist that gets tossed up in­to the air. Sil­ver iod­ide is an in­ert chem­ic­al, mean­ing it won’t re­act chem­ic­ally with much in the en­vir­on­ment, but its struc­tur­al shape is per­fect for seed­ing ice crys­tals. Wa­ter va­por will col­lect around the sil­ver iod­ide and freeze in­to crys­tals, then those crys­tals will pre­cip­it­ate as snow. The snow fills moun­tain­sides, an, come spring, the snow melts and in­creases the fresh wa­ter sup­ply.

The Desert Re­search In­sti­tute op­er­ates sev­er­al such cloud-seed­ers in Cali­for­nia and has found that the pro­cess in­creases the pre­cip­it­a­tion out­put of a cloud by around 10 per­cent — though there is a lot of vari­ab­il­ity, cloud to cloud, and the ef­fect­ive­ness of the pro­cess has been de­bated. In 2003, a Na­tion­al Re­search Coun­cil study found little evid­ence in fa­vor of cloud-seed­ing, but mostly be­cause there wer­en’t enough data. “This does not chal­lenge the sci­entif­ic basis of cloud-seed­ing con­cepts,” the Na­tion­al Re­search Coun­cil as­sured in its con­clu­sion, call­ing for more re­search. “The sci­entif­ic com­munity now has the op­por­tun­ity, chal­lenge, and re­spons­ib­il­ity to as­sess the po­ten­tial ef­fic­acy and value of in­ten­tion­al weath­er-modi­fic­a­tion tech­no­lo­gies,” the coun­cil wrote. A study out of Wyom­ing is ex­pec­ted to be pub­lished in Decem­ber to more pre­cisely de­term­ine the be­ne­fit of cloud-seed­ing.

The Cali­for­nia cloud-seed­ers are stra­tegic­ally placed in its north­ern moun­tain­ous re­gion, where snowpack is an es­sen­tial com­pon­ent of the yearly wa­ter sup­ply. In the past year, the snowpack was de­pleted to one of its low­est re­cor­ded levels. As can be seen in the chart be­low, much of Cali­for­nia’s wa­ter comes from the snow-laden areas in the north­ern part of the state.

Not only has the state’s snowpack di­min­ished, the on­go­ing drought in Cali­for­nia has got­ten so bad that the state is los­ing mass, as NASA has ob­served from space. That has wide-reach­ing im­plic­a­tions for a state with a massive ag­ri­cul­tur­al eco­nomy. “The wa­ter short­age could res­ult in dir­ect and in­dir­ect ag­ri­cul­tur­al losses of at least $2.2 bil­lion and lead to the loss of more than 17,000 sea­son­al and part-time jobs in 2014 alone,” re­ports the Na­tion­al Sci­ence Found­a­tion. By 2030, Cali­for­nia is pro­jec­ted to have a wa­ter sup­ply-to-de­mand de­fi­cit of 1.6 tril­lion gal­lons a year, the U.S. In­teri­or De­part­ment has pre­dicted.

“Even cur­rently, the sup­ply and de­mand are some­what out of bal­ance,” Shawn Blosser, an eco­nom­ic con­sult­ant with the Blue Sky Group, a pub­lic policy con­sultancy, tells me. “There really is no single sil­ver bul­let that is go­ing to solve the prob­lem.

Part of the solu­tion is com­bat­ing the rising de­mand for wa­ter (Blosser, work­ing with the Cali­for­nia think tank Next 10 has de­veloped a menu of policy ideas to re­duce de­mand — the an­swers aren’t easy, or cheap.) But part of the solu­tion is also to in­crease sup­ply, by cloud-seed­ing or per­haps a more scal­able meas­ure such as waste-wa­ter re­cyc­ling. In all, Blosser and Next 10 pro­ject that an in­creased ef­fort to seed clouds could re­duce the loom­ing wa­ter gap by 26 bil­lion gal­lons in 2030, at a cost of $22 per acre-foot of wa­ter (325,851 gal­lons). That’s markedly cheap­er than oth­er tech­no­lo­gies to in­crease wa­ter sup­ply. Wa­ter de­sal­in­a­tion, for in­stance, would cost $1,890 per acre-foot of wa­ter pro­duced.

But seed­ers aren’t a defin­it­ive an­swer to Cali­for­nia’s wa­ter prob­lems. Be­cause they’re ground based, if clouds aren’t over the seed­ers to be­gin with, we’re out of luck. Plane-based seed­ers ex­ist, but pi­lots can’t al­ways fly safely in­to cloud areas with the highest seed­ing po­ten­tial.

Enter the cloud-seed­ing drone. The DRI is cur­rently test­ing plans for a cloud-seed­ing drone pro­gram, with the goal of de­liv­er­ing the most ef­fect­ive dose of sil­ver iod­ide to the clouds with the greatest pre­cip­it­a­tion po­ten­tial, wherever they may be.

It may sound like a stretch, but it’s im­port­ant to keep in­nov­at­ing in wa­ter re­source man­age­ment. Even if Cali­for­nia’s drought eases in the next year, Blosser ex­plained, the long-term trend of wa­ter de­mand out­pa­cing sup­ply will con­tin­ue.

“There has to be a co­ordin­ated ef­fort on a lot of fronts to both lessen de­mand and in­crease sup­ply, to get the de­mand and sup­ply back in­to bal­ance,” Blosser said.

{{ BIZOBJ (video: 4769) }}

What We're Following See More »
Manafort Offered Russian Billionaire Briefings During Campaign
22 minutes ago

"Less than two weeks before Donald Trump accepted the Republican presidential nomination, his campaign chairman offered to provide briefings on the race to a Russian billionaire closely aligned with the Kremlin, according to people familiar with the discussions. Paul Manafort made the offer in an email to an overseas intermediary, asking that a message be sent to Oleg Deripaska, an aluminum magnate with whom Manafort had done business in the past, these people said. 'If he needs private briefings we can accommodate,' Manafort wrote in the July 7, 2016, email.

Interest Rates Don’t Change
2 hours ago

"The Federal Reserve left its benchmark interest rate unchanged and said Wednesday that it would begin to withdraw some of the trillions of dollars that it invested in the American economy after the 2008 financial crisis. The widely expected announcement reflected the Fed’s confidence in continued economic growth...most Fed officials predicted in a new round of economic forecasts that the Fed would increase rates later this year."

Mueller Looking For White House Docs
2 hours ago

Special Counsel Robert Mueller "has asked the White House for documents about some of President Trump’s most scrutinized actions since taking office, including the firing of his national security adviser and F.B.I. director...Mueller is also interested in an Oval Office meeting Mr. Trump had with Russian officials in which he said the dismissal of the F.B.I. director had relieved 'great pressure' on him."

Graham-Cassidy to Get a Floor Vote Next Week
3 hours ago
All of Puerto Rico Without Power
4 hours ago

"Hurricane Maria has knocked out power to the entire island of Puerto Rico, home to 3.5m residents, emergency officials have said."


Welcome to National Journal!

You are currently accessing National Journal from IP access. Please login to access this feature. If you have any questions, please contact your Dedicated Advisor.