SACRAMENTO, Calif. — California has seen big changes in reservoir levels so far this rainy season and the trend is up for the foreseeable future.
At the beginning of the water year for 2020-2021, some major reservoirs, such as Lake Oroville, were at record lows. California's well-known reliance on water capture and transport was under severe strain until a record October storm provided quick relief.
More storms in December have continued to add water to the big reservoirs and more snowpack which will become future water in the Spring and Summer.
Folsom Lake is now well above average for this time of year and is approaching its maximum limit for the rainy season. Folsom Lake's primary use during the rainy season is for flood control. The lake has a series of gates and spillways to balance the need for future water while balancing the need to have buffer space for large storms that could quickly fill the lake.
Water releases ahead of big storms are likely in the American River.
The snowpack for much of the Sierra is above 200% for this time of year so there will be water to replace the water being released as the lakes typically reach their maximum capacity in early Spring.
Lake Oroville has come up more than 80 feet from its record low and now is at the third-highest level for this time of year in the last 5 years.
Other big reservoirs like Trinity and Shasta are still well below average for this time of year, at close to 50%, but have also come up in a substantial way since the beginning of this water year.
Recent storms were cold and produced more snow than rain and slower additions of runoff and water, but future warm cycles will melt the snow which is typically 30% of California's water supply.