Water & Drought

Lake Nacimiento will be 20 percent full by Labor Day. Where does all the water go?

One year removed from a particularly rainy winter, Lake Nacimiento landowners and boaters are facing a summer recreation season of dramatically lower water levels.

By Labor Day, Nacimiento will be too low to launch boats from most private ramps that dot a lake that has 163 miles of shoreline when it's full.

That's because Nacimiento — which has a total capacity of 377,900 acre-feet — is less a lake and more a huge agricultural reservoir used by Salinas Valley landowners in Monterey County.

Since it was built in 1957, recreational users, farmers and environmentalists have spent decades jockeying for control of the lake's water — a resource that has increasingly become like liquid gold.

This year, Nacimiento is expected to contain about 20 percent of its water by Sept. 1, down from 51 percent on April 18.

Nacimiento as a reservoir

So where does all the water go?

Thanks to agreements made in the 1950s, San Luis Obispo County retains rights to 17,500 acre-feet of water per year, while Monterey County is allowed to withdraw 180,000 acre-feet of water per year.

Salinas Valley landowners financed construction of the dam, which captures water from the Nacimiento River, with a $7 million bond.

The facility was built to control flooding on the Salinas River, which flows north through the green vegetable fields that fill a valley that's known as America's Salad Bowl. It also recharges the groundwater used to irrigate those fields.

The Salinas River flowing through King City in Monterey County. Lindsey Holden lholden@thetribunenews.com

Water is released from one of three Nacimiento outlets and flows down the Salinas River toward Monterey Bay, percolating through the riverbed into the aquifer below. These "conservation releases" are typically made during the spring and summer, when water is most scarce.

During the early 2000s, the Monterey County Water Resources Agency (MCWRA) built the Salinas Valley Water Project, which diverts river water to supplement pumped groundwater.

To receive the permits to build the project — which includes a diversion facility near Castroville — MCRWA also agreed to release water from Nacimiento to sustain a threatened species of steelhead trout that uses the Salinas River for migration.

A biological opinion paper released by the National Oceanic and Atmospheric Administration's National Marine Fisheries Service directs the MCWRA to release water at certain times based on specific conditions.

For example, when the MCWRA releases water for irrigation, it must flow all the way to the Salinas River Lagoon to allow fish to move between the ocean and the river.

Due to the drought, the MCWRA didn't operate the diversion facility in 2014, 2015 and 2016. The MCWRA released an average of 41 cubic feet per second in 2015, during the height of the drought.

A cubic foot per second represents the rate of speed at which water is released. One cubic foot per second is equal to about 449 gallons per minute.

In 2017, when the Central Coast had its rainiest winter in years, the MCWRA released an average of 565 cubic feet per second. Although significantly more water was released, the additional rain made up for the loss.

Lakeside residents brace for a dry summer

This year, more water will again go to Monterey County. But this time, a winter of below-average rainfall will cause lakeside residents to feel the loss more acutely.

Phil Humfrey, who serves on the Nacimiento Regional Water Management Advisory Committee (NRWMAC), has maintained a house in the lake's Cal-Shasta community since 1978 and has lived there full time since his retirement 19 years ago.

Nacimento Fire housing102518
Lake Nacimiento as seen from Cal Shasta, a lakeside community in San Luis Obispo County. The reservoir was 51 percent full in this photo, and is currently at 27 percent of total capacity. Lakeside residents are threatening a lawsuit over alleged mismanagement of the reservoir. David Middlecamp dmiddlecamp@thetribunenews.com

"Living at Lake Nacimiento is like living a dream," he said in an email.

Humfrey said he and his wife have seen water levels fluctuate over the years, from full to almost empty.

When there's more water, they enjoy relaxing on their dock, barbecuing and people-watching.

"There are lots of little coves where you can anchor a boat and just enjoy the nature," Humfrey wrote. "We have deer, rabbits, foxes, bobcats, bald eagles, and even the occasional mountain lion."

The last time the lake was nearly empty, there was almost no water near Humfrey's house. He and his wife could walk across the bottom to Oak Shores, another lakeside community directly north of Cal Shasta.

Lake Nacimiento water elevations from October 1958 to October 2016. Monterey County Water Water Resources Agency

When the lake's elevation is lower than 730 feet, most of the 30 private ramps around the lake can't be used to launch boats, Humfrey said.

By Aug. 1, the lake is expected to hit 733 feet, according to the MCWRA's 2018 release schedule. Humfrey said the elevation will likely dip below 730 feet by the middle of the month.

Nacimiento's water level last dipped below 730 feet in November 2016, before the influx of rain that arrived that winter.

In response to the drop in water levels, NRWMAC has gathered more than 6,000 signatures on a petition to prohibit proposed water releases.

"While we recognize the Salinas Valley farmers need water, and they are entitled to their fair share, we abhor the way MCWRA has mismanaged this precious resource," the petition reads. "MCWRA is obligated to manage the water it controls for the benefit of all of the citizens of California."

Despite the low levels, not all ramps will be unusable. Mark Sandoval, general manager of Monterey Lakes Recreation Co., said visitors to the Lake Nacimiento Resort marina should be able to launch boats all summer.

The resort is located closer to the lake's eastern boundary — the head of the dragon many people think Lake Nacimiento resembles — where there's always more water.

"It's not always the water level but the perception of the water level that drives business to the lake," Sandoval said.

Last year's wet winter sent people to the lake in droves, and the resort generated $3.3 million in revenue — significantly more than it did during the previous year.

Even though the resort will have water throughout the summer, Sandoval said he's expecting a season closer to 2016.

"We'll be alright," he said. "We'll keep moving our marina out."

Salinas Valley farmers rely on Nacimiento water

Just north of Nacimiento, sprinklers spray lettuce-filled fields on either side of Highway 101 with water, some of which was likely stored in the reservoir.

Billboards and murals depicting farmers displaying their bounty line the road as it winds into the Salinas Valley.

John Baillie's family has grown, packed and shipped celery, broccoli, Brussels sprouts and cauliflower in the Salinas area for decades.

Baillie has been part of the Monterey County Water Resources Agency's Reservoir Operations and Advisory Committee, which helps guide lake management, for the past 25 years.

His family's now mostly retired from the grower-shipper business and leases their land to other farmers. Even so, he remains invested in the reservoir that has long sustained an area dominated by agriculture.

"Once the dam was built, (the Salinas River) quit flooding the ground," Baillie said. "We could farm longer in the year."

Water stored in the reservoir behind the dam also "improved water quality tremendously" when it was released and filled mineral-rich valley aquifers, he said.

"The best place for it is to let it percolate back underground," Baillie said of Nacimiento water.

Baillie said he understands lake residents and recreational enthusiasts want to see more water stay in the reservoir. But that's not Nacimiento's true purpose, he said.

"We understand that there is another use of the lake, but primarily it is to store water and release it."

Lindsey Holden: 805-781-7939, @lindseymholden
Related stories from San Luis Obispo Tribune