Farm Progress

The worsening drought and falling water levels at the Lake Mead storage reservoir on the Colorado River is a concern for those in low desert agriculture.Even with desert agriculture's river seniority, the possibility exists that the water supply could be threatened if the water level at Mead falls low enough.

February 23, 2016

6 Min Read
<p><strong>Agricultural leaders speaking at the Yuma County Agriculture Water Conference included from left: Mark Killian, Arizona Department of Agriculture; Thomas Buschatzke, Arizona Department of Water Resources; and Terry Fulp, U.S. Bureau of Reclamation.</strong></p> <p> </p>

The phrase “Don’t Mess with Texas” suggests leaving the good things associated with the Lone Star State alone.

The same could be said in the low desert farming regions in Arizona and California where Colorado River surface water irrigated in vegetable fields allows growers to produce about 95 percent of the nation’s supply of winter veggies.

Like their Texas counterparts, desert vegetable growers have a good thing going with senior water rights on the Colorado River. They know it and aim to protect it.

Yet the worsening drought and falling water levels at the Lake Mead storage reservoir on the Colorado River is a concern for those in desert agriculture. Even with river seniority, the possibility exists that the water supply could be threatened if the water level at Mead falls low enough.

Terry Fulp, director of the U.S. Bureau of Reclamation’s Lower Colorado Region, discussed Colorado River water issues during a panel discussion at the Yuma County Agriculture Water Conference held in Yuma, Ariz. in January.

System working as designed

Overall, Fulp shares an overall upbeat message on how the reservoir system on the Colorado River is working at lakes Mead and Powell (both storage reservoirs). He says Lake Mead has worked well so far to achieve good water management for river water users in the lower Colorado Basin states - California, Arizona, and Nevada.

“We are really blessed in the system to have this amount of reservoir capacity (Mead and Powell combined). It’s what makes it (the system) work over time,” Fulp told the farm water crowd of about 200.

“We’ve been able to collect uphill water in high flow years and doll it out in low flow years. It’s worked quite well to date, he said. “The question is how well will it work in the future?”

This is a huge question which only time will answer. Yet Fulp believes enough flexibility exists in the laws and agreements which comprise the “Law of the River” to work through immediate drought challenges.

“With Mother Nature throwing this drought and potentially the worst droughts at us, we tend to use up the flexibility. There could be a point at some time in the future where we hit the constraints of the Law of the River. I don’t believe this will happen in my lifetime,” Fulp said.

Not flexible enough?

Not everyone agrees with his view, Fulp admits, including some from academia who suggest that the LOTR is “old, antique, and un-mobile” and simply not flexible enough.

The Reclamation leader said, “I believe those ‘calls’ are wrong. It has served us well to date. It will continue to serve us into the foreseeable future.”

Doubts about the system are largely linked to falling water levels Mead tied to drought. As of mid-January, Lake Mead was at 39 percent full or 61 percent empty – depending on one’s perspective. Lake Powell was 48 percent full (or 52 percent empty).

Fulp says lower water levels at Mead can cause three problems: increased risk of a water shortage on the river for water users, especially those in Arizona.

Second, lower lake levels reduce the efficiency for power generation. Each one-foot decline in Mead’s water depth, he says, reduces Hoover Dam’s generating capacity by about 5.7 megawatts.

The third impact is on recreation. Each 10-foot drop in Mead’s elevation costs about $2.1 million to extend the boat ramps to the lower water level.

Mead water level is critical 

For Arizona agriculture, the major focus is on Mead’s declining water depth. Last summer, the water level dropped just below 1,075 feet, the trigger level where the U.S. Department of the Interior could declare a level one shortage on the Colorado River and reduce water deliveries.

Under a level one shortage, California would not lose a drop of its river apportionment. Nevada would lose some water, but Arizona would take the lion’s share of the cut – 300,000 acre feet of water. The entire reduction would be in river deliveries via the Central Arizona Project to farmers in central Arizona who could pump groundwater to help make up the difference.

Also on the water panel was Arizona Department of Water Resources Director Thomas Buschatzke who discussed the probability of shortage calls on the Colorado River based on studies and forecasts. He said the likelihood of a level one shortage call is zero percent this year, 18 percent in 2017, 42 percent in 2018, 47 percent in 2019, and 35 percent in 2020.

The probability of a level two or three shortage (1050 and 1025 feet respectively) at Mead, Buschatzke says, is zero percent this year, 18 percent next year; 52 percent in 2018, 65 percent for 2019, and 59 percent in 2020.

Looking at Arizona’s water use as a whole, he pegged the state’s 2014 water budget at seven million acre feet. The Colorado River and groundwater each provide 40 percent of the state’s water supply (80 percent total) with the balance from state rivers (17 percent) and reclaimed water (3 percent).

Buschatzke says Arizona agriculture uses 73 percent of the state’s water supply for food and fiber production. The balanced is used for municipal water use (21 percent); and industrial use (6 percent).

Will El Nino help?

Despite the worsening drought, Fulp offered a ray of hope. The current El Nino weather system has delivered higher than average precipitation across the nation’s Southwest. He says a good El Nino system helps replenish the Colorado River Basin.

Of the nine largest inflow years in the Colorado River Basin over the last 100 years, Fulp says three were (tied to) strong El Nino’s.

The good news about the current El Nino, he says, is it should help northern California. This helps the basin system since the Metropolitan Water District (MWD) takes water off the Colorado River.

“If they (MWD) could get their system filled back up then, then they could start storing water on the lake (Mead) instead of taking their apportionment value.”

Maintain farm water supplies 

Also speaking at the water conference was Mark Killian, director of the Arizona Department of Agriculture. His overall message was to maintain current water supplies for farming at current levels - and not for out-of-state farmers who want to start farming in Arizona or towns and cities looking for more water in the future for growing populations.

“Leave our water alone – let us keep it,” said Killian, an Arizona farmer and rancher who grew up in the orange business in Mesa on the outskirts of Phoenix.

Killian noted that Arizona agriculture is a $17 billion industry which employs about 88,000 people - either directly paid by agriculture or their income is derived from money tied to farming.

Water leader foresight

The director praised previous Arizona water leaders for their foresight and vision to create state reservoirs, a water banking authority, and other measures to help the state better weather future droughts.

Killian stressed the importance of maintain current water supplies for Arizona agriculture to feed the growing population, and help preserve the nation’s future prosperity.

“There is a moral imperative that people begin to recognize that the single most important strategic industry in America today is not our ships, planes or missiles, but the food we grow,” Killian said.

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