The two largest reservoirs in California are already at 'critically low levels' and the dry season is just starting

Against the backdrop of the water crisis in the Colorado River Basin, where the country's largest reservoirs are plunging at an alarming rate, California's two largest reservoirs — Shasta Lake and Lake Oroville — are facing a similar struggle.

Years of low rainfall and snowpack and more intense heat waves have fed directly to the state's multiyear, unrelenting drought conditions, rapidly draining statewide reservoirs. And according to this week's report from the US Drought Monitor.

The two major reservoirs are at "critically low levels" at the point of the year when they should be the highest.

This week, Shasta Lake is only at 40% of its total capacity, the lowest it has ever been at the start of May since record-keeping began in 1977. Meanwhile, further south, Lake Oroville is at 55% of its capacity, which is 70% of where it should be around this time on average.

This week, Shasta Lake is only at 40% of its total capacity, the lowest it has ever been at the start of May since record-keeping began in 1977. Meanwhile, further south, Lake Oroville is at 55% of its capacity, which is 70% of where it should be around this time on average.

This week, Shasta Lake is only at 40% of its total capacity, the lowest it has ever been at the start of May since record-keeping began in 1977. Meanwhile, further south, Lake Oroville is at 55% of its capacity, which is 70% of where it should be around this time on average.

This week, Shasta Lake is only at 40% of its total capacity, the lowest it has ever been at the start of May since record-keeping began in 1977. Meanwhile, further south, Lake Oroville is at 55% of its capacity, which is 70% of where it should be around this time on average.

Shasta Lake is the largest reservoir in the state and the cornerstone of California's Central Valley Project

A complex water system made of 19 dams and reservoirs as well as more than 500 miles of canals, stretching from Redding to the north, all the way south to the drought-stricken landscapes of Bakersfield.

Shasta Lake's water levels are now less than half of historical average

According to the US Bureau of Reclamation, only agriculture customers who are senior water right holders and some irrigation districts in the Eastern San Joaquin Valley will receive the Central Valley Project water deliveries this year.

"We anticipate that in the Sacramento Valley alone, over 350,000 acres of farmland will be fallowed," Mary Lee Knecht, public affairs officer for the Bureau's California-Great Basin Region, told CNN

For perspective, it's an area larger than Los Angeles. 

"Cities and towns that receive [Central Valley Project] water supply, including Silicon Valley communities, have been reduced to health and safety needs only."

A lot is at stake with the plummeting supply, said Jessica Gable with Food & Water Watch, a nonprofit advocacy group focused on food and water security as well as climate change. 

The impending summer heat and the water shortages, she said, will hit California's most vulnerable populations, particularly those in farming communities, the hardest.

"Communities across California are going to suffer this year during the drought, and it's just a question of how much more they suffer," Gable told CNN. 

"It's usually the most vulnerable communities who are going to suffer the worst,.

So usually the Central Valley comes to mind because this is an already arid part of the state with most of the state's agriculture and most of the state's energy development, which are both water-intensive industries."