How Does Your Garden Grow? One Marijuana Farm Fights the Drought With a Pond

Reports across the nation blame California Cannabis farmers for using too much water during a record drought. About a month ago, Time Magazine titled an article Pot Is Making California’s Epic Drought Worse. Two weeks ago, the LA Times posted an op-ed called Pot growers endangering California watersheds and wildlife. Smaller media outlets suggest that marijuana is actually causing the drought.

One media outlet pointed out that “The University of California Cooperative Extension in Tehama County said water usage for a traditional agriculture crop is measured in gallons per day, per serving size.” And that “[t]he closest to marijuana would be a head of lettuce, which uses around 1.5 gallons of water per day to grow.” Yet, it failed to note that a lettuce plant grows one head of lettuce and a marijuana plant often grows multiple pounds of pot–or thousands of “servings.”

Nonetheless, local watersheds are drastically affected by withdrawals by cannabis farmers. And, government agencies have been serving warrants looking for illegal water diversions.

Under the circumstances, some growers are looking for ways to get water to their crops without adversely impacting the environment. In this video, a Mendocino farm waters its cannabis and its veggies with a two million gallon pond. (See here for more about that farm.)



  • They are not the only one. We’ve been working with many farmers throughout Humboldt and Trinity counties for years in terms of water conservation, pollution prevention and habitat restoration. These are the watershed stewards we need to praise in the cannabis industry.

  • Would someone clarify how much water a plant takes… he says 6 gallons a day, but I’ve heard that is the maximum or is it the average?

    • Expressing water use as gallons per plant is a big problem for marijuana because the plants can be so different depending on the strain, the size of the full-grown plant, how and where they are grown (cool coastal zone or hot inland zone).

      The biggest blunder made by government officials is estimating that the plants need 6 gallons per day and then multiplying that by the entire growing season from seedling to finish—usually they pick 150 days. Any knowledgeable experienced gardener, whether vegetable or marijuana, knows that figure is bogus—you don’t drown young plants with that much water and most pot farmers I know don’t even water every day, except during the hottest weather when the plants transpire heavily to protect the leaves.

      A better way to frame the water needs of marijuana is to calculate how many gallons it takes to produce a pound of finished buds. For me it’s about 300 gallons for an outdoor plant, so if a pot plant produces one pound of product, then it takes 2.2 gallons per day averaged out over 140 days. Just realize that on a hot day a full grown plant will need more while on a cool day in late spring a start in a small container only needs a small spritz to keep the soil moist and the start growing at an optimum rate. A farmer growing light dep style in a greenhouse uses less water than anyone (except indoor growers) because by controlling the light cycle he forces the plants to finish in a shorter period of time.

      Look at any other agricultural product and gallons per unit of product is the way water use is most often expressed; things like a head of lettuce, a pound of broccoli, a pound of table tomatoes or even one almond kernel, the most famous water guzzler in California which takes 1.1 gallon per kernel, or 10% of California’s developed water supply to grow all the almonds in the state.

      The other way agriculture looks at water is by how many dollars does a measured unit of water produce—the economic value of the crop. That’s why farmers in the Central Valley continue to plant almonds and pistachios in the state’s worst drought in history, because of all the legally crops grown in California nuts produce the most profit per gallon of water. If you consider how much profit marijuana produces per gallon then all the other crops in California are left behind in the dust.

      Now I realize a few hard-headed people are going to scream “BUT IT’S ILLEGAL TO GROW POT!”, but they are ignoring that dollars are dollars and even the dollars made from illegal crops get circulated in the legal economy. The finer point is that the state and federal governments don’t get their cut at the front end from taxes on the product or the farmer’s undeclared cash income; government is pushed to the back of the line and get’s it’s money through the taxes marijuana money generates when it gets spent and the income taxes generated by all the legal jobs the marijuana industry creates, like the people who make and sell the products growers need to produce their crop. Government doesn’t like being last to get a share of the profits of other people’s labor.

  • Okay, either my experience has been hallucinatory or plants not right on the coast require RADICALLY more water. We grew killer dope. Half to one gallon a day. In pots, but even directly into the ground it doesn’t take that much.

    I knew a guy who used to pack the water on his back to his plants. Twice a week. I don’t know how many plants he had. I know they were well hidden and watched him go by with his water tank, maybe ten gallons, on his back, TWICE a week. He grew killer dope.

    What? What? What?

  • one guestamit☆

    My experience, and that of many whom I have asked, is that 6 gal/day/plant is way too much water!!! That much will most likely cause root rot & kill/mold the plant. Its not too far off from growing tomatoes. Less water near harvest. They need to be checked for water needs and not just put on some drip system that dumps on a timer. A fair guess would be average of 4 gal per every 7 days including fertilized water-anyone else venture a guess? Considering less water use later in season. For water use perspective, almonds equal out to approx one gallon water per nut to produce. I just hope these water regs are put onto big ag if they want to come after small farmers, esp considering how much of our water they get. Water use depends on your soil, is it in a pot or in the ground (if in the ground is it clay soil, etc), are you growing plants that come in early/late season, are you using a good mulch, how hot/windy does your spot get, is it outdoor/greenhouse or dep, do you have some idiot who “accidently” drains a tank working with you or someone who understands the need to be careful & conserve, does your lady friend need to do laundry/shower everyday (no hour showers LA girls!), the genetics of the plant to some degree, etc. Most folks say a seed plant gets way bigger than a clone plant, for instance. Like most farming there are many factors, with the added factor of human water use in most pot gardens. Some plant strains are known to be bigger/smaller than others. There are many many water conscious folks in the hills as well as water wasters. I know folks who bought water meters for their hoses and have been keeping track of water use for the whole season, year after year. Most also have found the most productive strain for their land and the best way to grow said strain after years of trial and error. Unfortunately a lot of new folks who are just here to grow dont have years of experience and know to get lots of water tanks, etc. I think some documentation about water rules for new land buyers, and perhaps mandatory check by water official could help.

    • Matthew Meyer

      It’s so relative that blanket statements are likely not to be valid in all cases.

      A big plant grower using three yards of soil is not going to drown a plant with six gallons of water per day.

      And, they will have a much larger harvest than someone watering a gallon a day onto a 20 gallon pot.

      Another commenter thinks cannabis doesn’t need that much water, as he and buddies grew “killer” herb guerrilla style, with just a few gallons schlepped in per week. He doesn’t mention the per-plant average of the harvest.

      Maybe cannabis will turn out to be like wine, with the best qualities emerging from slightly stressed plants. Once the current emphasis on plant counts goes away, we might actually find people giving up the overfeeding and overwatering for maximum yields.

      • A slightly stressed plant sends more energy to the flowers, that’s just Nature’s survival strategy to reproduce and continue the species. Over-watered plants with too much nitrogen make lots of useless leaves and weaker stems. Looks nice and green to the uninitiated. Forget the leaves, concentrate on learning how to grow roots, because the roots are what sends the raw materials to make buds.

  • Nick thrasher

    Top shape

  • Matthew Meyer

    Six gallons a day may or may not be a reasonable average for water usage of a cannabis plant, but it’s not a useful comparative measure to anything.

    This has been one of the real weaknesses of the current push to discuss the environmental impacts of cannabis: there is almost no weighing of costs and benefits–it’s almost as if the discussion is purposely phrased only in terms of costs in order to provide ammunition for continued prohibition, or, failing that, a “Kryptonite model” of cannabis regulation.

    So I decided to work up some figures that put cannabis’s ostensible water usage in some context of its value as a cash crop, with a comparison to almonds to help guide the examination.

    My aim was to get a sense of the value produced per unit of water.
    1) There are about 900k acres of almond orchards in the state;
    2) At 4 acre-feet per acre, that’s 3,600,000 acre-feet (1.173 trillion gallons)
    3) At 4 billion dollars wholesale crop value, that works out to 293 gallons / dollar

    ALMONDS—-> 293 gallons per $1 value

    4) Using the CDFW’s Scott Bauer’s figures, cannabis uses 6 ga / day
    5) Over a 6 month growing season, that’s 180 days x 6 ga=1080 ga / plant / season
    6) 2lbs./plant @ $1000/lb= 1080ga / $2000=.54 ga / dollar

    CANNABIS—-> 1/2 gallon per $1 value

    Conclusion: almonds require nearly 300 gallons to produce a dollar of value; cannabis requires half a gallon per dollar, SIX HUNDRED TIMES MORE VALUE per unit water!

    Now, why do you suppose this kind of comparison isn’t part of the discussion in Sacramento right now?

    • Thank you!!!! well done. The rules need to apply to all farms, and they need to pay the same rates. Cities & farms alike. Water rates are ridiculously low in places like LA. Plus 6 gallons a day is such overkill, literally! I also notice none of the studies seem to have happened in watersheds, like the Mattole, where there have been major efforts to conserve. At least a comparative analysis!!! All about whats wrong instead of offering useful suggestions.

    • the water use has been so all over the place, the 6 gallon figure so repeated since non -MJ grower Scott Bauer offered it as a guess has been requoted again and again like a game of telephone…other more experienced guesses have been far lower, which makes your calculation even more conservative.

      Wouldn’t we expect experienced growers could show the yield as more like .2-.35 gallon per 1$ value.

      Interesting calculation, thanks for the idea. And remember Scott Bauer was guessing and that efforts to conserve water by growers would yield even more savings in water use.

      • 6 gallons a day would mean you’re giving your plants 1 quart every hour 24/7 which in my opinion would more than likely kill your plants from root rot.
        6 gallons a week on average would probably be more accurate unless you’re talking about plants that were 10′ tall from start to finish.

      • Matthew Meyer

        My understanding is that Scott Bauer got those numbers from EGA best-practices publications, though Hezekiah Allen has since disavowed them.

        I do think there are gardens that use this much, on average, per plant. But that’s not even the point: it’s about putting the information in context of both the impact and the value created.

        I find the issue getting twisted in the media: the question becomes a yes-or-no, “Is pot bad for the environment?,” rather than an open-ended “What is the best way to minimize impacts from cannabis cultivation?”

        It comes down, I think, to whether you want to “make pot go away” or learn to live with it.

        • As always…well said!

        • No, in his study for the CDFW Scott Bauer cites a white paper presented to the Humboldt County Board of supervisors regarding the proposed medical marijuana ordinance in 2010 by the old Humboldt Grower’s Association, which morphed into the EGA. Hezekiah was with the Mattole Restoration Council at that time.

          My understanding from an email correspondence with a person who actually worked on the paper is that the white paper relied on water use figures from the defunct Mendocino County Medical Marijuana Ordinance that the assistant U S attorney Melinda Haag shut down. Nothing was scientifically measured, it was all a back-of-the-envelope estimate based on drip line used to water plants in which the objective was to produce maximum bud weight, so we’re talking about 7 pound and up producing plants in a 25 square foot canopy. See page 113 of the document for the details.

          Do you get what has happened? A sloppy estimate with no science behind it has now become the gold standard authoritative reference for water use by marijuana. Now that a California Department of Fish and Wildlife scientist with a specific agenda to protect salmon that is definitely biased against all pot growing has published a paper that validates non-science as scientific truth. Nobody seems to give a hoot where the figure came from, much less the crazy amount of variables.

          Maybe some day someone will actually do some real science and settle this controversy, like getting a water meter and measuring the water use, the biomass of the plant and other pertinent variables that any crop scientist at UC Davis uses.

    • Nice presentation Matt. The latest data is that there are now over a million acres of almonds in production in the Central Valley and that the acreage is increasing an estimated 1.5% per year, even though they have no guarantee that there will be surface water delivered down the canals for those trees, meaning they are going to spend the next 20-25 years emptying the aquifer below. That’s how long an almond tree remains productive. After that it seems no one cares what happens, the growers will have made their money and can quit or if there’s still some water they can plant another generation. Both almonds and pot are driven by an insatiable desire by consumers, the difference is more rain falls here than we could ever use to grow pot—even in these severe drought years.

      • Matthew Meyer

        Thanks for the kind words, Uti, it means a lot coming from you.

        Cadillac Desert is showing me that water in the west has never been about sustainability, and always about megalomania and money. It puts Jerry Brown’s twin tunnels in context…he’d like to finish his dad’s job, just like Dubya and GHWB.

  • Looking at stats for estimated water usage for one golf course in Iowa states that the usage will be approximately 32 to 35 million gallons for one year. One club in California is limited to 56 million gallons a year. In the rest of the article it is stated that usage is privileged information, so total use by all golf courses is kept confidential. There are 1,140 golf courses in the state though. So assuming an average of 40 million gallons per year would mean that the total water usage would be around 45+ billion gallons per year. That is an extraordinary amount of water. When compared to what pot growers might use in a season, it is easy to see that there would be no comparison to the massive volume that golf courses use.

    Agriculture in California uses around 80% of the total for California. Here is where the state should bring measures to bear to get farmers to conserve through the use of more efficient delivery systems, like the Israelis have done for decades. I would think that it would even make sense for California to offer tax breaks to farmers as an inducement to upgrade their equipment with the most advanced technology available. That would be good governance. Another thought on good governance. Has anyone stopped to consider that Jerry Brown was also governor during the drought in the mid 1970s? He has now been governor for the last 6 years. Why is it that this leader of our state did not consider the possibility of another drought impacting our state? Even though science has known about the drought history of California for at least the last 50 years or so. Does that sound like responsible leadership? It sure doesn’t to my mind.

    • Fucking Hypocrites

      [edit] The illegal excavaction that created this pond is exactly what you [edit] love to rant and rave about when being shown in a negative light, but these guys build a pond thats most likely not permitted and now their saints. And for the record a 200 gallon pot will drink 10% of its soil volume in water. Leave farming to the farmers and go back to your cubicles!

      • How do you know that it was not permitted?
        It appears to be built in a area away from a water course filled by rain water which does not require a stream bed alteration permit. All this pond looks to require is a grading permit for moving over 50 yards of material.
        Very east permit to obtain.
        If it was build as fire protection during a heavy fire year, no permits are required.
        If it is AG land some counties to not require a permit to build a storage pond at all.
        You could speculate from either direction.
        The bottom line is these are the practices that are necessary for proper rural land stewardship.

      • Nobody needs a damn permit to do the right thing by the environment, so yeah he’s a hero and just the kind of person the marijuana industry needs.

        There used to be a time when state agriculture extension services would help people create ponds on their property. Ponds not only store rainwater, they provide wildlife habitat and when wildfires happen they are a godsend for the helicopters to dip water and for the pumper trucks to fill their tanks.

        But ponds do need to be properly engineered to the specific sites and that’s where the agencies could better help instead of making up fee schedules to grab their share of the profits. More ponds please.


    1) NEVER call a pond a pond of you own property!


    Never call it anything but that, act stupid and tell any green nazis you don’t know the meaning of a pond, but you know that you have a Sediment Retention Basin.

    2) plants don’t use six gallons a day. If someone managed to use six gallons a day, along with nutes, we would have planes hitting bean stalks going into the clouds.

    it’s just a bunch of nonsense that George Orwell warned us about when it comes to media and the memory hole.

    When they don’t have a leg to stand on, they make shit up.

    I will pray for giant windstorms that will wipe their flying black clouds from the sky when they try to do their evil deeds, you should too. If enough people send up the vibe to bring down every flying black cloud- they will leave and never return.

    PEACE & LOVE for People

    Pain and Anguish for trans humanist machines.

  • Does anyone care?

    That pond just built along Thomas above the sc school right along the road looks sketchy and most likely had no permits. It blows out and it takes the road with it. Check it Kim it’s not far from ur place.

  • Better get rid of those broadmites!

  • Why do you think this pond story applies in humboldt?
    It doesnt!
    You need permits and permission, don’t be giving people ideas here, they see your pond from the air and you’ll get a visit from the govnas fish cops and the waterboard, besides needing permits from the county.
    This isn’t mendo so scrap it!

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