Now McQuilkin, executive director of the Mono Lake Committee, a nonprofit group organized to save and protect the bowl-shaped ecosystem, said, "The worst-case scenario is probably not going to happen. ... These weather events have put us all on a different track. Who knows what the rest of the winter will bring?"
Many lakes and reservoirs have been slowly rising since October as Northern California saw increases in rain and snow. But January has been particularly wet thanks to "atmospheric river" storms.
Jana Frazier, a tour guide for the Department of Water Resources at Lake Oroville, has a view of the dam and the reservoir from her office.
The numbers tell part of the story: The lake has risen more than 90 feet since December, she said -- 21 feet during the 24-hour-span between Saturday and Sunday alone.
But seeing the change in person is even more striking. Before this weekend's storm, officials were launching boats from the bottom of one ramp. Water had climbed to the top of the ramp by Tuesday morning, Frazier said.
When Frazier returns to the ramp Thursday, she expects that the parking area with the boat launch will be underwater and officials will have to move to a different ramp on higher ground.
"It's really weird," Frazier said. "We've been so low in water for so long, it seems strange to drive across the dam and see it almost full."
Lake Oroville, Lake Shasta and other reservoirs in Northern California are key pieces of the state's water system, which moves the resource from the Sierra Nevada to cities and farmlands. While the recent rains are making a dent, officials said it's still too early to say the drought is over.
Rain and snow are expected to continue through Thursday, with some higher elevations expected to see up to 20 inches of snow over the course of the week. Several key rivers have overflowed, and more flooding is expected.
In Sonoma County, about 3,000 residents were asked to evacuate as the Russian River swelled, damaging some homes. Along the Cosumnes River in the town of Wilton, about 2,000 people were told to move to higher ground.