In southwestern United States, the water level of the Colorado River has dropped to historic lows amid a drought that has lasted 23 years.

The river is more than 2300 kilometers (1,450 miles) long and runs through a number of western states and into Mexico.

U.S. federal officials have announced a Tier 2 water shortagefor the iconic river. Starting in January, the government will impose cuts in water deliveries to Nevada (8%) and Arizona (21%), and also Mexico (7%). 

The Colorado River Basin is very important to the U.S. southwest. The river provides water to 40 million people in California, Arizona, Wyoming, Colorado, New Mexico, Utah and Nevada. Of these, California gets the most water from the river.

The shrinking level of the Colorado River, along with rising temperatures and depleting groundwater supplies, has led to a severe drought in California.

There are 37.2 million people in California affected by drought, according to the National Integrated Drought Information System (NIDIS). 

“We can't get around a shortage of water. There's only so much that we have, and we have less now than we had before," president and CEO of the Public Policy Institute of California (PPIC), Mark Baldassare told ABC10. "And we're gonna have to find our way to a solution to making the best use of what we have,” Baldassare added.

The drought is leaving some cities and towns struggling to supply enough water for their homes and businesses. 

The Metropolitan Water District of Southern California has imposed unprecedented watering restrictions on six million residents.

Over the past three years, the region has recorded the lowest amount of water, according to Brad Coffey, district manager of the Water Resource Management Group. 

Camarillo in Ventura County, supplied by the Calleguas Municipal Water District, had to reduce outdoor watering to one day a week or find other ways to save 35 percent.

Earlier this month, California Governor Gavin Newsom released a document called “California’s Water Supply Strategy – Adapting to a Hotter, Drier Future.”

Its aim is to help the state adapt to the impact of climate change on its water supply and calls for investment in new water sources.

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