Improved Water Efficiency Paramount to Future of California Farmers, Officials Say

Growers will need to save more water and use less as the state will likely become drier in the long term.
The James E Roberts Memorial Bridge near Yosemite National Park
By Thomas Sechehaye
May. 27, 2024 16:58 UTC

It is dif­fi­cult to over­state how impor­tant California is to United States agri­cul­ture.

According to the 2023 Feeding the Economy report, nearly 13 per­cent – $1.1 tril­lion (€1.0 tril­lion) – of the United States’ agri­cul­tural out­put comes from California.

We will con­tinue to get these short burst peri­ods of heavy rain­fall, but droughts are not going away any­time soon. We need always to be plan­ning for the next drought, even when it’s cur­rently rain­ing out­side.- Caitlin Peterson, asso­ciate direc­tor, PPIC Water Policy Center

The Golden State is the largest agri­cul­tural pro­ducer in the U.S. by a wide mar­gin. Texas and New York, sec­ond and third, com­bine to pro­duce as much agri­cul­tural out­put as California.

The state is also respon­si­ble for vir­tu­ally all U.S. olive oil pro­duc­tion, with the California Olive Oil Council, a trade asso­ci­a­tion, esti­mat­ing that the Golden State pro­duces between two and four mil­lion gal­lons (7.5 to 15 mil­lion liters) each year.

See Also:State-of-the-Art Irrigation Management Leads to Rising Yields in California

As a result, water is top of mind for many farm­ers, includ­ing the state’s olive grow­ers, and an increas­ing point of ten­sion between rural and urban Californians, espe­cially after years of intense drought.

According to the California Department of Water Resources (DWR), agri­cul­ture accounts for approx­i­mately 40 per­cent of the state’s total water use and about 80 per­cent of all devel­oped water, which is con­trolled and man­aged for var­i­ous pur­poses in California.

The state’s wet win­ter has lifted vir­tu­ally all of California out of drought, accord­ing to the U.S. Drought Monitor. Still, offi­cials are wary of improv­ing agri­cul­tural water use effi­ciency to meet the state’s water needs.

It’s impor­tant to under­stand that all regions in California are vul­ner­a­ble to cli­mate change, and their vul­ner­a­bil­i­ties are often inter­con­nected, includ­ing in agri­cul­ture and water man­age­ment,” Sabrina Cook, DWR’s water use effi­ciency imple­men­ta­tion sec­tion man­ager, told Olive Oil Times.

She said that some of the respon­si­bil­ity for improv­ing water effi­ciency falls on the agri­cul­tural water providers, the largest of whom must sub­mit man­age­ment plans that include a descrip­tion of the best pro­fes­sional prac­tices.

In the fer­tile San Joaquin Valley, which com­prises the south­ern half of the state’s Central Valley, author­i­ties are already tight­en­ing water reg­u­la­tions, which some have spec­u­lated could spur dry­land olive cul­ti­va­tion in the region.

Mike Anderson, a cli­ma­tol­o­gist at DWR, warned that the state’s wet win­ter is the result of cur­rent atmos­pheric con­di­tions and should not be viewed as a long-term reprieve from drought.

While cli­mate dri­vers like El Niño change weather pat­terns that impact California, each year water sup­ply and flood and drought risk are dri­ven by the tim­ing, pace and scale of atmos­pheric rivers,” Anderson told Olive Oil Times.

He explained that when large storms come close together, the pace is accel­er­ated, and flood­ing tends to occur. On the other hand, drought con­di­tions occur when California misses out on these storms and has more warm, dry days in win­ter.

Reservoirs and ground­wa­ter pro­vide a buffer to the dry con­di­tions that can hap­pen in a sin­gle dry year,” he said. Multiple dry years tend to lead to greater drought impacts.”

Caitlin Peterson, the asso­ciate direc­tor and a research fel­low at the Public Policy Institute of California’s Water Policy Center, con­firmed that ample win­ter rain­fall alle­vi­ated the drought but warned this may only be a reprieve.

Thanks to 2023’s impres­sive win­ter and this year’s con­tin­ued rain­fall,” she told Olive Oil Times. This is great news for agri­cul­ture and the state’s water sys­tems.”


However, Peterson added that all indi­ca­tors point towards more fre­quent, longer dry spells and larger swings in inten­sity between peri­ods of drought and rain in California’s future.

We will con­tinue to get these short burst peri­ods of heavy rain­fall, but droughts are not going away any­time soon,” she said. We need always to be plan­ning for the next drought, even when it’s cur­rently rain­ing out­side.”

As California braces for more rain, the ques­tion arises whether this helps refill aquifers, reser­voirs and water basins.

See Also:Corto Bets on Olives as Crop of The Future in Changing Sacramento Valley

For refill­ing reser­voirs, a high-vol­ume, short-dura­tion storm is as good as any,” Peterson said. Our reser­voirs are in pretty good shape over­all at the moment; all but a few have more water in them than the his­tor­i­cal aver­age for this time of year. That is a stark dif­fer­ence from where we stood in February 2022.”

Unfortunately, flashy’ weather events like this are not as help­ful for refill­ing under­ground aquifers,” she added. For recharge to hap­pen, the water needs to have some res­i­dence time, mean­ing it has to hang around for a while so it has time to per­co­late down through the soil.”

When soils are sat­u­rated with water, addi­tional water runs off into water­ways or drainage sys­tems instead of per­co­lat­ing down to the water table.

Some of this can be stored in our reser­voirs and released later in the sea­son to be used for ground­wa­ter recharge, but this brings its chal­lenges because reser­voir oper­a­tors also have to think about man­ag­ing flood risk, hydropower and ensur­ing enough sup­plies for other pur­poses,” Peterson said.

As rain con­tin­ues to pound the state, con­cerns about poten­tial dam­age arise, with some wor­ry­ing that high-vol­ume, short-inter­val storms cre­ate more dam­age to the infra­struc­ture and crops than pro­vide help.

As California sees more pre­cip­i­ta­tion falling in shorter, more intense peri­ods, DWR is work­ing with fed­eral, state and local part­ners to col­lab­o­rate and coor­di­nate oppor­tu­ni­ties to enhance ground­wa­ter recharge when the larger storms come through and update reser­voir oper­a­tions,” Anderson said.

This pat­tern of more punc­tu­ated storms sep­a­rated by warm spells will become more com­mon dur­ing our wet sea­son,” he added. Flood impacts to infra­struc­ture and crops depend on the tim­ing, pace and scale of atmos­pheric river storms.”

Bekele Temesgen, a land and water use sci­en­tist at DWR, believes that edu­ca­tion is crit­i­cal to improv­ing water use effi­ciency among the state’s farm­ers and empha­sizes the use of free tools such as the California Irrigation Management Information System (CIMIS).

CIMIS is a net­work of auto­mated agro-cli­matic weather sta­tions that col­lect weather data, such as solar radi­a­tion, air tem­per­a­ture, wind speed and rel­a­tive humid­ity and cal­cu­late ref­er­ence evap­o­tran­spi­ra­tion.

Temesgen said CIMIS helps farm­ers save water, energy and money by inform­ing them to apply the right amount of water at the right time.

A recent study by the University of California – Berkeley found using CIMIS data saves at least five mil­lion acre-feet (six bil­lion cubic meters) of water per year in agri­cul­ture,” Temesgen told Olive Oil Times. This trans­lates to a mon­e­tary sav­ing of at least $1.5 bil­lion (€1.4 bil­lion) in urban water costs for land­scape irri­ga­tion.”

In addi­tion to these sav­ings, using the right amount of water at the right time will improve envi­ron­men­tal health by reduc­ing sur­face runoff and deep per­co­la­tion of con­t­a­m­i­nated water and help us mit­i­gate the impacts of cli­mate change through reduc­ing energy use,” he added.

According to Temesgen, the data col­lected by CIMIS allows olive farm­ers to deter­mine the crop water require­ments. This can be done by mul­ti­ply­ing ref­er­ence evap­o­tran­spi­ra­tion by the crop coef­fi­cient for olives avail­able on the web­site.

Additionally, the state offers a series of grants to agri­cul­tural com­pa­nies, includ­ing olive farm­ers, for invest­ments in water-sav­ing and effi­cient-use projects. Among these is a $23.3 mil­lion (€21.7 mil­lion) pro­gram offer­ing grants to grow­ers who limit agri­cul­tural water use.

Cook said that so far, six of these grants cov­er­ing 4,317 acres (1,747 hectares) of land had been awarded, per­ma­nently reduc­ing demand on California’s aquifers while remain­ing avail­able for flood pro­tec­tion, active ground­wa­ter recharge and sus­tain­able local farm­ing.”


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