Planting Seeds - Food & Farming News from CDFA

To defeat the drought look under your feet – from the National Journal

vineyard

By Ted Hesson

If you strolled past a vine­yard on Don Camer­on’s land four win­ters ago, you would have seen something odd: wa­ter, up to a foot-and-a-half of it, drench­ing the grapev­ines and turn­ing a nor­mally pic­tur­esque field in­to an un­sightly bog.

The 63-year-old Camer­on is the gen­er­al man­ager and vice pres­id­ent of Ter­ran­ova Ranch, a 5,500-acre farm in Cali­for­nia’s San Joa­quin Val­ley. Or­din­ar­ily, he wouldn’t flood-ir­rig­ate his crops—the farm doesn’t have dir­ect ac­cess to wa­ter from a river or stream, even when the weath­er is wet. In­stead, he re­lies on ground­wa­ter and typ­ic­ally em­ploys drip ir­rig­a­tion, a pre­cise and eco­nom­ic­al meth­od of dol­ing out wa­ter to crops, in or­der to con­serve the un­der­ground re­source.

So, the soggy plots were an ex­cep­tion­al sight, but there was a reas­on be­hind it. Camer­on was host­ing a risky ex­per­i­ment that, if suc­cess­ful, could help re­plen­ish the ground­wa­ter sup­ply un­der his fields, a vi­tal re­source for his farm and oth­ers like it.

In Cali­for­nia, still in a pun­ish­ing four-year drought, wa­ter is an in­creas­ingly sought-after—and con­ten­tious—com­mod­ity. Busi­nesses and elec­ted of­fi­cials have had to re­think their ap­proach to the crit­ic­al re­source. The long-term fear is that the drought—not caused al­though likely ex­acer­bated by cli­mate change, sci­ent­ists say—is only a pre­view. A 2014 pa­per pub­lished in the journ­al Geo­phys­ic­al Re­search Let­ters found that, while the main cause for the cur­rent drought was nat­ur­al vari­ab­il­ity in the cli­mate, hu­man activ­ity made the drought 15-20 per­cent more severe. The six coau­thors poin­ted to “a chron­ic dry­ing trend that … is pro­jec­ted to con­tin­ue grow­ing throughout the rest of this cen­tury.”

This could en­danger the state’s long-term sup­ply of ground­wa­ter. Dur­ing the cur­rent drought, farm­ers have used ground­wa­ter as a backup to keep their crops watered and thriv­ing. But if green­house-gas emis­sions keep mak­ing Cali­for­nia warm­er, droughts could be­come more fre­quent and in­tense, fur­ther strain­ing the state’s ground­wa­ter sup­ply. It won’t run out any­time soon, but the long-term risks in­clude dried-up streams and wet­lands, sink­ing land, and pos­sibly a de­grad­ing of ground­wa­ter qual­ity bey­ond re­pair.

The con­cern about ground­wa­ter sup­ply led the Nat­ur­al Re­sources Con­ser­va­tion Ser­vice, part of the fed­er­al De­part­ment of Ag­ri­cul­ture, to award a team of en­gin­eers $75,000 to ex­plore in­nov­at­ive flood­ing tech­niques to re­plen­ish the ground­wa­ter re­serves be­neath Camer­on’s farm. (The Ter­ran­ova Ranch matched the grant dol­lar-for-dol­lar.) Here’s how the pro­ject was in­ten­ded to work, be­fore the drought set in: Whenev­er the north fork of the nearby Kings River floods, the ex­cess wa­ter is di­ver­ted to his prop­erty. It in­und­ates cer­tain fields for long peri­ods of time, let­ting the wa­ter seep in­to the soil and re­fill the aquifer. The goal: to see if the crops, or­din­ar­ily ir­rig­ated with pre­cise amounts of wa­ter, can with­stand a long peri­od of flood­ing without dam­age.

When the river last flooded in 2011, he sent some of the over­flow to fal­low fields and also to act­ive vine­yards, where the wa­ter sat for two months and five-and-a-half months, re­spect­ively. The farm also over-ir­rig­ated its pista­chio orch­ards and fields of al­falfa hay, so that wa­ter would pass down through the roots and reach the aquifer. His prop­erty was an ideal choice for the pro­ject, be­cause of its ac­cess to flood­wa­ter and its sandy, por­ous soil. Ac­cord­ing to a fol­low-up re­port, 30 per­cent of the wa­ter di­ver­ted to the fields dribbled in­to the aquifer; the rest of it re­duced the ground­wa­ter Camer­on needed to draw for ir­rig­a­tion. In the vine­yards, where the wa­ter sat longer, 50-75 per­cent of it filtered down to the aquifer.

And, no crops were hurt in the pro­cess; in­deed, some of them thrived. “We were able to demon­strate and to doc­u­ment that we could ac­tu­ally re­charge land with ex­ist­ing crops in place,” Camer­on says.

The 2011 ex­per­i­ment went so well that the Cali­for­nia De­part­ment of Wa­ter Re­sources gave a $5 mil­lion grant to the Kings River Con­ser­va­tion Dis­trict, a pub­lic agency, to work with Camer­on to in­crease the pro­ject’s ca­pa­city. Camer­on is en­thu­si­ast­ic, so much that the farm plunked down $2 mil­lion of its own cap­it­al on top of the grant. They’re adding a more per­man­ent in­fra­struc­ture—canals, pipes, pumps—that will let him move lar­ger quant­it­ies of storm wa­ter or flood­wa­ter to his farm. Of course, they’ll need a heavy flood to test it out, something he hopes will come soon: “We’re build­ing the ark,” he says, “but we haven’t seen the flood yet.”

Camer­on’s in­nov­a­tion, of us­ing flood ir­rig­a­tion to re­fill the ground­wa­ter sup­ply, could be tried else­where, of­fi­cials say, as long as the farm­ers have ac­cess and rights to the wa­ter. But per­suad­ing farm­ers that the re­ward out­weighs the risk won’t be easy, says Lu­ana Ki­ger, a spe­cial as­sist­ant to Cali­for­nia’s state con­ser­va­tion­ist at the fed­er­al ag­ri­cul­tur­al agency. An orch­ard can take sev­en years be­fore the trees start to pro­duce, say, al­monds. “You do not want to waste that in­vest­ment of sev­en years of no in­come,” Ki­ger says, “and then, the first year you get some ac­tu­al nuts on the tree, you drown out your trees.”

Sci­ent­ists don’t know for sure how much ground­wa­ter ex­ists in Cali­for­nia, so they can’t really say when the re­source could run out. But Jay Famigli­etti, a hy­dro­lo­gist at the Uni­versity of Cali­for­nia (Irvine), be­lieves the Cent­ral Val­ley could lose its easy-to-ac­cess, pot­able ground­wa­ter in sev­er­al dec­ades if cur­rent trends con­tin­ue, leav­ing com­munit­ies scram­bling for sup­plies.

This isn’t hy­po­thet­ic­al. In East Port­erville, an un­in­cor­por­ated town in cent­ral Cali­for­nia pop­u­lated mostly by poor Latino farm work­ers, nearly half the house­holds re­por­ted in June that their wells had gone dry due to the drought and over-ex­trac­tion. Res­id­ents couldn’t af­ford to dig deep­er, so the Ag­ri­cul­ture De­part­ment stepped in last month with a $500,000 grant to­ward a new com­munity well.

Ground­wa­ter has al­ways been vi­tal to Cali­for­nia’s wa­ter sup­ply, and any threat to its fu­ture is scary. In a nor­mal year, it makes up about 38 per­cent of the total wa­ter sup­ply; in a dry year, 46 per­cent or more, ac­cord­ing to the state’s De­part­ment of Wa­ter Re­sources. While the re­source is fairly abund­ant—an es­tim­ated 2 tril­lion gal­lons of wa­ter have been pumped from the ground dur­ing the cur­rent drought—dec­ades of us­ing too much of it could cause the land above the shrink­ing aquifers to sub­side. Pump­ing out un­der­ground wa­ter can dam­age build­ings, cause roads to buckle, and change the el­ev­a­tion of streams and canals.

“Ground­wa­ter levels in much of the Cent­ral Val­ley have gone lower than we’ve ever meas­ured,” says Gra­ham Fogg, a pro­fess­or of hy­dro­geo­logy at the Uni­versity of Cali­for­nia (Dav­is) Cen­ter for Wa­ter­shed Sci­ences. The farm­ers in many loc­ales, he adds, “are pump­ing more ground­wa­ter than the sys­tem can sus­tain.”

In the San Joa­quin Val­ley, south of San Fran­cisco, so much wa­ter has been pumped from the ground that the land is sink­ing faster than ever be­fore—by nearly two inches per month in some loc­a­tions, ac­cord­ing to a re­port in Au­gust by the state’s wa­ter agency. That puts in­fra­struc­ture at risk. Be­sides the threat of land sub­sid­ence are longer-term wor­ries that aquifers might be­come chron­ic­ally de­pleted or that, in places closer to the Pa­cific Coast, salt­water might ir­re­vers­ibly con­tam­in­ate the ground­wa­ter.

The con­cerns have been so wide­spread that Cali­for­nia’s le­gis­lature passed a pack­age of laws in Au­gust 2014 to reg­u­late the us­age of ground­wa­ter. Grow­ers were ini­tially skep­tic­al of the le­gis­la­tion, which al­lows loc­al agen­cies to man­age un­der­ground wa­ter sup­plies, but they even­tu­ally real­ized that change was in­ev­it­able, ac­cord­ing to Kar­en Ross, sec­ret­ary of the state’s De­part­ment of Food and Ag­ri­cul­ture. “Once it was signed in­to law,” she re­counts, “all of the or­gan­iz­a­tions rolled up their sleeves.”

In Ross’s mind, reg­u­lat­ing un­der­ground wa­ter re­sources will help farm­ers in the long run. She sees ground­wa­ter as “our sav­ings ac­count to get through a drought. But if we’re be­com­ing overly de­pend­ent on pump­ing ground­wa­ter in non-drought peri­ods, without do­ing pro­jects to re­charge those basins, we will not have that sav­ings ac­count for fu­ture droughts.”

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