CNN reports that the Colorado River is diminishing. It has severe implications for the farmers in Arizona and California that rely on it for irrigation, electricity, and drinking water supply.
Significance of the Colorado River
Snow melts from the Rocky Mountains of Colorado, Utah, and Wyoming, flowing through its tributaries, feeds the Colorado River. Its two vast drainage – the Upper and Lower Basins, feeding lakes and dams that supply 40 million people in seven western states and Mexico and irrigates more than 5 million acres of farmland (Kann, 2021).
The article says that “Las Vegas relies on the river for 90% of its water supply, Tucson for 82% and San Diego for around 66%”. Los Angeles, Phoenix, and Denver also depend on a huge portion of their water supply from the river. Experts that the river is the ‘lifeblood of the American West’ and cities that are now thriving would not have been possible without it.
The River is drying up
The continuous depletion of the Colorado River alarms scientist, farmers, and policymakers across the Southwest and could indicate. For two decades, the river has been plagued by overuse. The demands of water from the seven states have outpaced what the river can supply. According to the article, the river has shrunk by 20% since 2000, with climate change partly to blame (Kann, 2021).
The dwindling water supply from the river is affecting farmers who rely on it for irrigation and the lakes that depend on it to generate power.
In the past century, the Colorado River management decides how much water each state can draw from the river, a testy exercise that could sometimes lead to the Supreme court. But lately, states are having a more painful job of deciding who will receive less water. In the future, the decisions surrounding the division of water will become more contentious as the river shrinks, the article says.
Factors that contribute to the shrinking of the Colorado River
The article describes the factors that contribute to the worsening water problem in Arizona and California, even extending to Mexico in the years to come, to wit:
- The first is the agreement on water allocation made almost 100 years ago that hammered out the guidelines on how the Colorado River water will be portioned out to the seven states.
- Second, the water allocation was based on an overblown estimate of the river’s capacity, which has inflated the amounts of water portioned out to the states.
- Third, as dams and canals were built throughout the 20th century to generate electricity and supply water to neighbouring states, political actors ignored the reality that the river has its limits. These massive infrastructures have stretched the river beyond its limits for decades.
- Fourth, climate change is heating the atmosphere and melting the ice caps in the mountain ranges in southern Wyoming, western Colorado, and North-eastern Utah, which could reduce the amount of water flowing in the river.
- Fifth, the drought that began in 2000 and lingered for two decades has reduced the river flow and partially caused Lake Mead to shrink. The article cited a study on the North American megadrought published in Science journal, which finds that the period from 2000 to 2018 was the driest season for the Southwest since the 1500s and attributed half of the drought’s severity to climate change.
Scientist believes that the river’s reduced flow, insufficient snow and rain, the lingering droughts, and the increasing temperature of 1.4°C (2.5°F) across the river basin lead to another more serious event – the aridification of the region. How this event is unfolding is explained in the report.
Scientists believe that with no significant reductions in GHG emissions, the river flow can shrink by as much as 31% by the middle of this century.
On the other hand, farmers are pumping more water out of the aquifers as an alternative water source, which would allow them to survive the cuts from Colorado’s water supply, but digging more wells is not sustainable. It will soon deplete all the aquifers, making farming less and less profitable in the years to come.
Preparing for the future
The article explains that what will happen in the next 100 years hinges on the decisions surrounding the division and management of the Colorado River, which will take place in 2026. “A failure to reach an agreement could usher in an era of uncertainty for the basin’s 40 million water uses and increase the likelihood of legal conflicts”, according to John Ensminger, the general manager of the Southern Nevada Water Authority.
States and farmers are looking at other options to prepare for dwindling water supplies in the future. These options range from replacing farms with solar panels, wastewater treatment and reuse and the more expensive solution – desalination of the saltwater off the shores of Mexico if the water crisis worsens.
To read this interesting report, click the link below:
Kann, D., Rigdon, R., & Wolfe, D. (2021, August 21). The Southwest’s most important river is drying up. CNN. Retrieved from https://edition.cnn.com/interactive/2021/08/us/colorado-river-water-shortage/