News Summary

California’s Lake Oroville has reached full capacity for the third year in a row, a historic achievement for the state’s second-largest reservoir. As of June 15, 2023, the lake’s surface elevation was reported at 898.73 feet, just shy of its 900-foot total capacity. This major milestone signifies a welcome change amidst the state’s ongoing water challenges, as Lake Oroville sufficiently provides drinking water to millions of Californians. Nevertheless, concerns about drought conditions and invasive species persist, highlighting the need for continued vigilance in water management.

California—Lake Oroville, the state’s second-largest reservoir, reached full capacity on June 15, 2023, marking a historic milestone as it is the first time in the reservoir’s 57-year history that it has achieved this for three consecutive years. The California Department of Water Resources reported that, as of just a few days before this achievement, the reservoir was at 99% full, with its surface-level elevation reported at 898.73 feet, just short of the total capacity elevation of 900 feet.

When at full capacity, Lake Oroville holds an impressive 3.4 million acre-feet of water, which is sufficient to supply over 7 million households for a year. This reservoir plays a critical role in providing drinking water to around 27 million Californians and is essential for irrigating approximately 750,000 acres of farmland annually. The current water levels at Lake Oroville are reported at 121% of the historical average for this time of year, significantly contributing to California’s water supply amid ongoing concerns about drought conditions.

In addition to Lake Oroville, nearly all major reservoirs across California are above their historical average water levels, with the only exception being the San Luis Reservoir, which stands at 94%. This year’s wet winters have contributed to improvements in snowpack accumulation, alleviating some of the more severe drought symptoms seen in previous years.

Despite the positive milestones regarding water capacity, it is important to note the context of California’s water challenges. In 2021, Lake Oroville faced alarmingly low water levels, leading to dried, cracked lake beds and a renewed urgency regarding California’s water crisis. Currently, around 60% of California is classified as abnormally dry, with 40% experiencing moderate drought conditions and nearly 25% facing severe drought.

Additionally, while Lake Oroville is reaching record levels, there are environmental concerns to be aware of. Recently, during a boat inspection at the Thermalito Forebay, the invasive golden mussel species was discovered. This invasive species poses risks to aquatic ecosystems and drinking water infrastructure, heightening the need for vigilance among water management agencies.

The Department of Water Resources has indicated that during windy conditions when the reservoir is full, there may be minor flooding due to emergency spillway drains, a situation which is regarded as normal under these circumstances. Meanwhile, prosecutors have announced plans to fulfill 50% of the water requests from State Water Project contractors while maintaining caution due to the possibility of future dry conditions.

As California continues to navigate the balance between full reservoirs and the looming threat of drought, the significant achievement of Lake Oroville reaching full capacity three years in a row serves as both a beacon of hope and a reminder of ongoing water management challenges in the state.