Lower Colorado River Basin Can Still Expect Shortage Next Year

By Bret Jaspers
Published: Tuesday, June 25, 2019 - 12:57pm
Updated: Wednesday, July 10, 2019 - 9:33am

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lake mead
National Park Service
Lake Mead.

The Lower Colorado River Basin does not avoid a shortage in 2020 despite the plentiful snowpack on the Rocky Mountains this past winter.

Why? Well, the new Drought Contingency Plan defines different “tiers” of shortage. The Lower Basin will not drop into a Tier One shortage next year because Lake Mead will almost certainly remain above 1,075 feet in elevation. 

At the same time, Mead will likely remain under 1,090 feet. That triggers a Tier Zero shortage.

“Under Tier Zero conditions, Arizona takes a reduction of 192,000 acre-feet in its annual Colorado River entitlement,” said Suzanne Ticknor, assistant general manager at the Central Arizona Project. 

An acre-foot of water can cover one acre of land with one foot of water, or 325,851 gallons. The EPA says the average person uses 88 gallons of water a day at home, which equates to 32,120 gallons a year.

Arizona’s reduced supply in Tier Zero will affect certain users of the Central Arizona Project canal system. There will be a slight reduction to some Pinal County farmers, and the pool of so-called “excess water” will be eliminated.

Regular buyers of excess water have included the United States, the Arizona Water Banking Authority and the agency that replenishes groundwater in Central Arizona, which enables new home building.

The CAP is writing a new policy for excess water if and when it returns.

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