MENDOCINO Co, CA, 3/17/23 — For the first time in years, large swaths of California — about half, by some estimates — have been lifted completely out of drought, according to the U.S. Drought Monitor. Statewide, snowpack is at 200% of the average peak since 1981; California has had 149% of its average precipitation. The majority of Mendocino County is currently considered no longer in drought, with easternmost zones classified as “abnormally dry.”
That data, though, gives us a snapshot of a moment in time. It doesn’t show what the summer will be, what next year will bring, or what new challenges could be in store, as Nicholas Malasavage of the U.S. Army Corps of Engineers (USACE) illustrated for The Mendocino Voice in a phone conversation Thursday. He’s part of the team that manages outflows from Lake Mendocino and other area reservoirs.
“Let’s not forget the last few years,” he said. “We’ve had drought, we’ve had a pandemic, we’ve had wildfires. All these things that have directly impacted [Lake Mendocino], they’ve situationally or directly impacted our team that works there, too — just like they’ve impacted the communities that we hope the lake serves.”
How is Lake Mendocino looking?
The heavy precipitation this winter has brought Lake Mendocino’s highest water levels in recent years, rivaled only by 2016’s March water level. Boat ramps have reopened for the first time in several years. But the intense weather also meant downed power lines at the lake, weather damage to recreational assets, and complications amid rebuilding of the Pomo Day Use Area following damage from the Hopkins Fire.
In Malasavage’s experience, Mendocino County residents understand that double-edged sword of high volumes of water.
“The great thing about Forecast Informed Reservoir Operations (FIRO) is it created a lot of connective tissue between levels of government and agencies from National Marine Fishery Service to local county government — gaining more awareness and collaboration around the resource that is water, and also the hazard that is water,” he said. “The switch flips quick.”
Back in January, Malasavage’s team made the call to up water release to 3,000 cubic feet per second (cfs), letting go a large amount of water downstream once flood conditions lessened in order to free up room for more water storage. Knowing that historically January is early in the rainy season, he expected to recoup those amounts — and recoup they have. As evidenced by the daily operations schedule for this month, USACE is constantly making calculations around how much water should flow from Coyote Valley Dam at Lake Mendocino on any given day.
Greater transparency about those decisions has been part of his team’s work this year, Malasavage said.
“One thing we’ve started to change this year is to also message publicly why we’re not releasing, whereas historically, we only message to the public when we [release more water],” he said.
This approach is informed by personal experience as well as professional consideration.
“The two teams at both of our lakes, most of us are citizens in this watershed,” he explained. “Most of us are impacted by good or bad decisions that may or may not occur by our employer. We want to be good citizens and communicate our thinking, not just our actions.”
How does our rainfall impact groundwater?
The Ukiah Valley Groundwater Sustainability Agency (GSA), recently released its report on water year 2022, in which the Ukiah Valley Basin received 73% of long-term average precipitation. But in the two years prior, the basin received less precipitation than half the historical average, with less natural recharge than expected (when rain soaks through to an underlying aquifer).
“The soils are one of our best reservoirs,” Deborah Edelman of the Mendocino County Resource Conservation District (MCRCD) told The Voice in January. “Healthy soils can absorb way more rain than unhealthy soils.”
A table from the California WaterBlog designed to answer the question, “Is the drought over?” reported that soil moisture is at healthy levels for this year. Many reservoirs have also filled around the state. But groundwater is another beast, and while these healthier soils could contribute to better recharge of our aquifers, it can take years for groundwater to reach healthy levels after prolonged periods of drought.
Meanwhile, lingering impacts like dead or dying trees, over-pumped aquifers, depleted fish and bird populations, and reduced salmon survival rates will need more than one good water year to recover. In a promising move for salmon populations, the California Department of Fish and Wildlife (CDFW) plans to release Chinook fry from hatcheries into the Sacramento River this year, after being forced to truck the fish farther afield since spring 2020 due to poor conditions.
Infrastructure makes a big difference in water supply
In a prime example of water shortage being about not just rainfall but infrastructure, Lake Pillsbury — one of two storage reservoirs as part of the Potter Valley Project — is currently at 101% of its target water storage curve for this time of year. But PG&E has announced the decision to leave open the Scotts Dam spillway gates, which usually close in the spring to allow storage of up to 20,000-acre feet of additional water, after analyses found an increased risk of seismic activity at the dam.
“The most effective means of reducing risk in the near term is to store less water in the reservoir, and the most feasible way to store less water is achieved by leaving the spill gates open — which in years past have been closed from April through October,” the utility wrote in a news release Thursday.
The spillway gates will remain open in the future, too, according to the release, meaning Lake Pillsbury will likely consistently store less water in years to come.
Lake Mendocino, at least, should see its best summer in years.
“By July, our water control manual allows us to hold on to pretty much everything,” Malasavage said. “We’re in that space right now of going from the depths of the winter to the depths of the summer. So we’re still getting storms, but what we can safely hold on to, and what we need to plan for in a potential next storm, is changing as we transition throughout the season.”
Note: Kate Fishman covers the environment & natural resources for The Mendocino Voice in partnership with a Report For America. Her position is funded by the Community Foundation of Mendocino, Report for America, & our readers. You can support Fishman’s work with a tax-deductible donation here or by emailing [email protected]. Contact her at KFishman@mendovoice.com or at (707) 234-7735. The Voice maintains editorial control and independence.