Lettuce Saves The Colorado River

By Alan BjergaAlan Bjerga and Cindy HoffmanCindy Hoffman

Water levels are up this winter at Lake Mead, a gauge for the Colorado River’s ability to supply 30 million people with water, thanks partly to a surprising hero: lettuce.

Farmers’ switching to lettuce, which uses less water because it’s cultivated only part of the year, from alfalfa, a thirsty year-round crop, helped push the lake to 1,087.6 feet (331.5 meters) above sea level as of Jan. 31. That’s more than 1 foot higher than a year ago and above the benchmark of 1,075 feet, at which point regional water restrictions kick in.

The improvement, which brought a sigh of relief to a dry region, is mostly due to a record snowpack in the Sierra Nevada mountains that ended California’s drought by early 2017. But some credit goes to farmers, the biggest users of the region’s water, who in some places have been doing exactly what climate experts say they should be doing—switching crops for conservation reasons.

A Canal Connects the Valley to the Lake

NEVADA

Lake Mead

ARIZONA

CALIFORNIA

Colorado River

Salton

Sea

All-American Canal

Imperial

Reservoir

Imperial

Valley

MEXICO

0

100 Miles

NEVADA

Lake Mead

ARIZONA

CALIFORNIA

Colorado

River

Salton

Sea

All-American Canal

Imperial

Reservoir

Pacific Ocean

Imperial

Valley

0

100 Miles

MEXICO

NEVADA

Lake Mead

CALIFORNIA

ARIZONA

Colorado River

Salton

Sea

All-American Canal

Imperial

Reservoir

Pacific Ocean

Imperial

Valley

0

100 Miles

MEXICO

A look at 28 years of data from the Imperial Valley—a major crop-growing region spanning southeast California, bordering Mexico and Arizona and relying on Colorado River water—shows how farmers battling water scarcity have shifted acreage.

Acreage planted in alfalfa, a low-value forage crop, has declined 25 percent to 148,642 acres since 2001, according to December 2017 figures. Lettuce growth has increased 79 percent to 31,382 acres in the same period.

Acres Receiving Water From Imperial Irrigation District

Lettuce

35K

30

25

Lettuce

acres are

+79%

from 2001

20

15

10

Alfalfa

200K

Alfalfa

acres are

−25%

from 2001

175

150

125

100

2001

2016

Lettuce

35K

30

Lettuce

acres are

+79%

from 2001

 

25

20

Water rationing agreements started in the early 2000s

15

10

Alfalfa

With water rationing, fewer acres of alfalfa were planted

200K

Alfalfa

acres are

−25%

from 2001

175

150

125

100

2001

2016

Lettuce

35K

30

Lettuce

acres are

+79%

from 2001

 

25

20

Water rationing agreements started in the early 2000s

15

10

Alfalfa

With water rationing, fewer acres of alfalfa were planted

200K

Alfalfa

acres are

−25%

from 2001

175

150

125

100

’01

’02

’03

’04

’05

’06

’07

’08

’09

’10

’11

’12

’13

’14

’15

’16

Lettuce

35K

30

25

Lettuce

acres are

+79%

from 2001

 

20

Water rationing agreements started in the early 2000s

15

10

Alfalfa

With water rationing, fewer acres of alfalfa were planted

200K

Alfalfa

acres are

−25%

from 2001

175

150

125

100

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

The shift is a combination of market and government incentives, said John Fleck, director of the University of New Mexico’s Water Resources Program in Albuquerque. Water-sharing agreements with local governments have reduced use at the same time that distribution networks for fruits and vegetables have improved, making it possible to ship fresh lettuce and other produce to more markets.

“Cutting water use doesn’t have to be the end of agriculture,” Fleck said. “Farmers with less water to use will maximize their drops, and find a way to maximize their profits.”

The changeover challenges the conventional wisdom that water demands don’t ease. It doesn’t, however, solve the long-term problems of the Colorado River. This year could be more difficult, with snowpack well below normal, according to the U.S. Bureau of Reclamation. The basin’s population may rise as much as 91 percent by 2060.

Farmers with less water to use will maximize their drops, and find a way to maximize their profits.

John Fleck, director, Water Resources Program, University of New Mexico

But at least one thing climate experts say must happen to manage the problem appears to be happening. That could put off the day of reckoning while the region seeks lasting solutions, Fleck said.

“You can go a long way with conservation,” he said. “The problem isn’t fixed, but we’re buying time.”