The Colorado River system provides water for around 40 million people. A 25-year drought has endangered this system, prompting seven states and Mexico to accelerate conservation efforts.
Story Transcript
NARRATOR: On January 1st, 2020, the Colorado River System will issue cuts in water supply to Arizona, Nevada and Mexico – areas that are already suffering from a 25-year drought.
The cuts are necessary steps for maintaining the sustainability of the Colorado River System, which is threatened by a complete collapse if nothing is done, and which would affect tens of millions of people .
NANCY J. SELOVER, Ph.D., ASU, SGSUP & Co-Chair, Drought Monitoring Tech Cmte: We’ve been in a drought, closer to 25 years since about 1994. We’ve had many, many more dry winters than wet winters.
NARRATOR: Nancy J. Selover is a State Climatologist and Co-State-Coordinator from the Arizona State Climate Office, as well as a Co-Chair of the Drought Monitoring Technical Committee.
NANCY J. SELOVER: If we continue with the drought, we’ve seen that [geologists] done studies that look and see in the past that we’ve had droughts as long as 60 years or more.
If that turns out to be what we have now, that is certainly going to be a problem. And so we are going to get to that point where we have, you know, the demand for water exceeds the supply. Potentially more than what we have at this point.”
NARRATOR: In the context of such a drought and uncertainty, the importance of the Colorado River System comes to the forefront. According to the U.S. Bureau of Reclamations:
“The Colorado River System (System) is composed of portions of seven States—Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming and Mexico. 30 to 40 million people depend on the water delivered throughout the system. It is also estimated that about 4 million acres of agricultural land are irrigated with its water.”
Yet after 25 years of drought, the effects on the system are evident. There are two main threats to the Colorado system: One, that rivers and streams contributing to the river flow carry less water, due to less rain or snow; and two, that water from the reservoirs evaporates on days of extreme heat.
NANCY J. SELOVER: Arizona has been doing a lot of water banking, pumping water back underground in order to preserve it, so it doesn’t, it’s not sitting out in a lake evaporating.
NARRATOR: On Lake Mead, the minimum water level required to generate power at the Hoover Dam is 1,050 feet. “Dead Pool” is a term used to refer to the condition when the reservoir reaches the lowest water outlet of the Dam, at 895 feet. Anything under below that level that would mean no more water from the system for tens of millions of people. A study by the U.S. Bureau of Reclamation projected a level of 1,089 feet by January 1st. 2020.
In 2015 and 2016, the Lake Mead Hoover Dam System came near critical levels. Amid intense drought, water levels at Lake Mead reached 1,080 feet, a mere 30 feet from shutting down the electric generating plant. Conservation efforts ramped up after that.
We can see the effect of conservation in this graph. The black dotted line under the green area is where the water level would be, if not for a multi-state, bi-national concerted effort at water management.
This included voluntary contributions by members to leave water in the lake – which are represented in blue – also systemic conservation efforts – represented in red – and a couple of wet seasons, represented in Green. These factors turned around what otherwise would have been a negative trend.
SARAH PORTER, Director, Kyl Center for Water Policy, ASU: In 2017, we had a really wet spring and that helped a lot. And then last year, we had a lot of snow and that helped. So we had a little bit of weather that helped sort of “buy time” until the drought contingency plan could be implemented.
NARRATOR: Sarah Porter, is the Director of the Kyl Center for Water Policy, and the Morrison Institute For Public Policy from Arizona State University.
SARAH PORTER: In the last several years, the Colorado System States and Mexico have worked on with the federal manager, the US Bureau of Reclamation, on conserving water in Lake Mead, and that effort to conserve water has done a lot to keep levels of the lake up.
NARRATOR: In May 2019, the Drought Contingency Plan, or DCP, for the Upper and Lower Colorado River basins was signed between Colorado, Arizona, Nevada, New Mexico and California. In June 2019, a Bi-National DCP was signed between U.S.A. and Mexico, under these agreements Arizona will take a 6.7% cut, Nevada a 3% cut, and Mexico also a 3% cut.
Barring a dramatic event, the DCP would maintain the status quo in the river system until 2026, when all parties involved plan to re-evaluate and negotiate a new agreement.
SARAH PORTER: For the most part, management of water is highly technical. It’s not a political thing.
In the negotiation of the Drought Contingency Plan, there was a lot of disagreement and there was zealous advocacy by various stakeholders on, you know, for their needs. They fought hard and worked hard to hammer out an agreement.
NARRATOR: Profesor Selover warns of an overall trend for further warming and drought, which may force states to plan and adapt to much more difficult circumstances.
NANCY J. SELOVER: Drought is a normal thing, drought is a constant, it comes in and goes, right. How long it lasts varies, it can last a very, very long time, a little bit drier than normal or can last a short period of time a lot drier than normal and occasionally, a long time, a lot drier than normal.
Warmer temperatures tend to make mid elevation areas, 5800 feet, 6200 feet, those kinds of places have more potentially more of their winter precipitation fall as rain rather than snow.
Snow is our most important resource, in terms of water, because it stays on the land sitting there all winter long. And then finally in the spring, it gets melted and goes into the reservoir system.
NARRATOR: The close calls of 2015 and 2016, served as lessons about how fast things can change when a few years of drought and extreme temperatures are stringed together, a particularly frightening thought when facing a trend of warming temperatures.