How California Reservoir Water Levels Will Change, According to Predictions

Many of California's reservoirs are far above their average capacity, but water levels are expected to change as the winter season progresses.

The U.S. Southwest has suffered from years of drought, and until recently, the most severe impacts have been centered around Lake Mead and Lake Powell and much of California. Last year, none of California was free from drought, and more than 16 percent of the state suffered from exceptional drought, which is the United States Geological Survey's (USGS) most extreme classification.

A wet winter and various storms throughout 2023 have continued to erase the drought throughout California. On Friday, AccuWeather meteorologists officially predicted that the state will be free from significant drought into 2025.

"AccuWeather experts today are exclusively forecasting that there will be no significant drought in California into the winter of 2025," AccuWeather Chief Video Meteorologist Bernie Rayno said in a video posted on X, formerly Twitter.

Rayno added that many of the state's reservoirs are "running well above the historical average."

AccuWeather Senior Meteorologist Paul Pastelok told Newsweek that many of the reservoirs' water levels will decrease through the fall as water use outpaces rainfall. However, the reservoirs are expected to rise again in the spring as melting snow supplements the water levels.

"They're not really rising now because they're not adding precipitation and the snow has melted," Pastelok said. "They are lowering little by little, but further into the wet season we will start to see more of that change."

Pastelok said mid-elevation reservoirs particularly will benefit from the winter season because much of that rain doesn't run off.

"This is the first time in several years that we have seen the state have pretty much no drought," Pastelok said. "So that's a good sign for next year."

Usually, rain and mountain snow have a beneficial impact on lakes and reservoirs over the winter months, but given that many of the reservoirs are already boasting above-average water levels, the wet winter months could be negative this year and contribute to "serious flooding," especially as meteorologists have predicted El Niño to be stronger than normal.

El Niño is a climate pattern that starts with warm water building up in the tropical Pacific Ocean west of South America. El Niño, which occurs every three to seven years, typically results in high precipitation for the southern part of the U.S., including California.

As of Friday, nearly 94 percent of California was free from drought, according to the U.S. Drought Monitor Map, a massive change from a year ago, when none of the state was drought-free. Above-average precipitation has proved beneficial to the state's lakes and reservoirs, many of which have recovered from their drought-stricken states.

Most lakes and reservoirs were above historical average markers, according to a map by the California Department of Water Resources. For example, Shasta Lake in northern California was 72 percent full, which is 131 percent of its historical average. Also in northern California, Oroville Lake was 71 percent full, or 135 percent of its average. Both lakes were severely depleted by the drought, and their recovery prompted before-and-after pictures across social media.

A year ago, the worst of the drought in California was focused in the central part of the state. Lakes and reservoirs there also are now well above average, including Don Pedro Lake and San Luis Reservoir, which were at 123 percent 180 percent of historical average, respectively.