Marijuana farms tap into Carrizo Plain’s scarce water — and SLO County is worried

The parched California Valley is facing a new drain on its limited water supply with a recent boom of cannabis farms in the area, prompting concern from San Luis Obispo County officials and some residents over the long-term impact.

It’s one reason why the county is considering banning cannabis farming in California Valley and the larger Carrizo Plain.

Groundwater is limited in the dry grassland in eastern San Luis Obispo County due to the small amount of rain and water draining into the area from streams, according to the 2012 San Luis Obispo County Master Water Report.

The limited water that is there has quality issues due to the internal drainage structure of the basin.

“It’s not a great water area. It’s very salty,” said Leslie Terry, supervising environmental health specialist with San Luis Obispo County. “It’s a very tough place. Very little water, very shallow water.”

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A small public water system serves the elementary school in the valley. Everyone else uses well water. Farmers in the area water their plants from wells on their own land, from a water delivery service or, last year, from a community well.

The arrival of marijuana farmers in need of water is reflected in county data on new well drilling.

In 2016, 20 new wells were drilled in California Valley. So far this year, 17 have been drilled, an increased pace that could almost double the number of last year, according to data from San Luis Obispo County Environmental Health Services.

By comparison, two were drilled in 2015 and one in 2014. A total of 263 wells have been drilled in the community since 1980.

“We never saw this California Valley cannabis cultivation coming,” county Supervisor Debbie Arnold said last year. “With the limited availability of water and remoteness, I don’t think that is an appropriate place for cultivation.”

Those who can’t afford to drill their own wells rely on water deliveries to feed their marijuana crops.

Larry Montengro, through his company The Water Boys, delivers water pumped from his own two wells in California Valley to about 60 growers in the area in a truck outfitted with a 2,000-gallon tank. A delivery costs about $150, and most farmers require about two deliveries a week during the growing season.

Montenegro pumps water from the ground into a tank, then transfers that water to his truck for delivery. He said he’s never had a problem refilling the two tanks on his land from the groundwater below.

Some county officials don’t seem so confident about the water supply. Lawsuits filed against a handful of growers claim that California Valley’s few areas with potable well water “are being drained for cannabis cultivation,” which could affect residents’ drinking water supply.

There is no sign that’s going to happen, said Andrea Horn, general manager of the California Valley Community Services District.

Last year, marijuana growers hauled truckloads of water from the community well, which many residents who live on the east side of the valley rely on for drinking water because their water is too salty.

The problem with heavy use of the wells, Horn said, was that the pump was overused and burned out, not that the well was dropping.

Since then, a lock was placed on the well, so residents now have to make an appointment to get a key and fill their tanks. That’s drastically cut down on the number of people using it.

Guzzling gallons: Marijuana vs. popular products

Cannabis isn’t the biggest water guzzler when comparing the amount it takes to produce popular products, according to data the San Luis Obispo County Planning and Building Department found.

Estimates of water usage to produce marijuana, in comparison to wine and hamburger meat were included in a report produced in preparation for an upcoming Planning Commission hearing about commercial cannabis regulations.

The report says:

▪  One pound of cannabis takes about 150 gallons of water. That equates to about one cup of water for one joint (assuming one pound produces 1,000 joints).

▪  One gallon of wine takes about 870 gallons of water. That equates to about 54 gallons for an 8-ounce glass of wine.

▪  One pound of hamburger meat takes about 1,800 gallons of water. That equates to about 600 gallons for a 1/3-pound burger.

Information about water use of cannabis is estimated by the Mendocino Cannabis Policy Council and the Emerald Growers Association and is based on an average 150-day growing cycle. The county report notes that water usage for cannabis cultivation varies on a variety of factors, including density, climate, indoor versus outdoor cultivation and strain.

Monica Vaughan

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