New Study Throws Environmental Spotlight on Marijuana Cultivation in Emerald Triangle

A study published yesterday looks at the effect of marijuana grows on water flow and on the wildlife that depends on it. Researchers examined four watersheds–three in Humboldt County and one in Mendocino County. The results do not look good for the fish. Water sucked out to produce glistening, sugary buds could, at times, exceed streamflow in three of the four watersheds which fits with witnesses who have recounted local waterways disappearing in places when they had never been known to do so before.

Total map

Map from the study. [Click to enlarge.]

The authors concluded from their research, “In the most impacted study watersheds, diminished streamflow is likely to have lethal or sub-lethal effects on state-and federally-listed salmon and steelhead trout and to cause further decline of sensitive amphibian species.”

The watersheds looked at in the research paper, Impacts of Surface Water Diversions for Marijuana Cultivation on Aquatic Habitat in Four Northwestern California by Scott Bauer et al, contain differing amounts of grows. The grows on the northernmost watershed cluster in one small section

Redwood Creek

Upper Redwood Creek

while the grows in the two central watersheds freckle the area densely.

Salmon Creek and Redwood Creek [There are two Redwood Creeks in the study. One in northern and one in southern Humboldt]

Salmon Creek and Redwood Creek [There are two Redwood Creeks in the study. One in northern and one in southern Humboldt]

Outlet Creek in Mendocino also has multiple grows spread across the study area.

Outlet Creek

Outlet Creek

The study authors estimated that each watershed contained between 23,000 to 32,000 plants each sucking an average of approximately 6 gallons of water per day during the growing season which they compared to grapes–about 3 1/3 gallons of water a day. (Though the the amount of product to feel pleasantly buzzed per gallon of water used would be another calculation altogether. Marijuana plants presumably produce large amounts of bud while grapes produce few bottles of wine per plant.)

According to the study, the four watersheds “are already designated as impaired for elevated water temperature and sediment by the U.S. Environmental Protection Agency.” Lower flows will exacerbate these issues and, according to the study’s authors, lead to fish dying in unacceptably high numbers. “Complete dewatering of stream reaches would result in stranding and outright mortality of salmonids, which has been observed by the authors at a number of [marijuana cultivation sites] just downstream of their water diversions.” Amphibians also could be at risk.

The authors warn that marijuana grows are more harmful to waterflow than logging. They state,

In contrast, timber harvesting, which until recently was the primary land use in forested ecoregions in the western United States, does not typically divert headwater streams in the same manner as [marijuana cultivation sites.] Timber harvesting operations, at least in California, have state regulatory oversight that requires bypass flows to maintain habitat values for surface water diversions.

Northcoast Environmental Center’s Facebook page posted the link to this study saying, “This is probably the most conclusive study on the watershed-scale impacts of unchecked marijuana production in our region….While there are responsible growers out there, they are being overshadowed by many more who are sucking streams dry. Time to nip it in the bud!”



    • I’m just curious, how would that help? Since quasi-legalization seems to have introduced this problem. It seems to me the price drop with full legalization would just promote more people to grow more pot, thereby using more water.

      • It would be grown on flat ground. Not extremely sensitive mountain stream watersheds.

      • Quasi legalization caused this through the lack of adequate regulations. If it is to be legal in any form, it needs sufficient regulations. Just as there are only so many liquor licenses issued to any given community, so too can there be restrictions on how many marijuana plantations an area will be allowed to support.

        • Cannabis farmers in these remote watersheds will be at an extreme disadvantage under wide-open legalization.

          The market itself should rapidly reduce the number of scenes in these areas, unless they are able to brand themselves favorably.

          The production caps and tight regulations you favor could actually produce *more* fragile-watershed grows if legitimate production is held too low, or if taxes are too high.

          On the other hand, even under state legalization these remote gardens may still find enough margin to keep operating if prices stay high enough in non-legal states.

          That’s California’s unique conundrum, and it makes it clear that federal legalization is the long-term solution.

  • Each plant sucking six gallons per day? That’s preposterous.

    • I’m curious about the water numbers also. The study authors do, however, give interesting sources for their numbers. They cite well-known marijuana advocate Jorje Cervantes–Cervantes J. Marijuana horticulture: the indoor/outdoor medical grower’s bible. Sacramento, CA: Van Patten Pub.; 2006 and US Governement—United States Department of Justice. Domestic cannabis cultivation assessment 2007. Johnstown, PA: National Drug Intelligence Center; 2007.

      • The numbers of gallons used in these illegal grows may or may not be exactly right. Not really the point. The operative word here is ILLEGAL, which lets be honest, most out in the woods are. No one can really argue with that, if they are being realistic. And so in any event we are in the worst drought seen in weather history out here in Calif. Any and all steps must be taken to try to correct unnecessary use of water, and surely to try to alleviate any further deterioration of the fish population. Not to mention other wild life that need to drink out of the streams. I’m not a eco-nazi, just a very concerned person worried about the state and the wildlife that are going to suffer as this drought continues, for who knows how long.

        • Well June, whether or not a grow scene is illegal is irrelevant to the problem of endangered fish being harmed. The problems are: are they diverting water at a time of the year when it affects stream flow and are their land use practices causing sediment discharge into the streams/

          • Correct. I wonder if there is a water test that could be taken in different portions of streams that lay people could do that could narrow down where the problems are coming from? I think a lot of hay and various preventive methods need to be deployed like yesterday. I have heard of subdivisions that were put in that the owners had to monitor the streams for a couple years. As said these problems are so huge the government is not capable fixing it. We all need to figure out a way to fix it.

      • Well, my ex grew dope and it for sure wasn’t getting anything approximating six gallons a day, and I know the number one problem for growers historically was getting water to their patches. I knew a guy who hauled it on his back to his plants every few days, and another who used a waterbed as his water tank. None of those guys used that kind of water. None of them industrial sized grows either, and sure the plants can get pretty big, but not six gallons a day big.

        I think maybe info from the feds on this particular matter is at least as likely to be purposely misleading as it is to be just plain sloppy science, but, well, I’ve gotten to the point where if the government is saying it, I assume it’s false until I can verify it.

      • Kym, have you seen the Cervantes book he references? I seem to remember reading somewhere the gallons per day in the book was unbelievably high.

        • Uti, I haven’t seen the book but I have known people who told me they watered more than 6 gallons per day. I also know people who do much less. I know Bauer’s calculations are more like guestimates but I have to say, that the real point in my mind isn’t how much water each plant might suck up. The real point is that I can see that the creek is dewatered. I don’t know what people are doing with the water but something more than drought is happening. Any water drawn out of the streams in June through Sept is causing the problem.

          • My gripe over the water use figure has to do with the Bauer Study being called “science” and will now be called the most authoritative study on marijuana cultivation water use.

            Science is not about guesstimates; it’s about discovering facts and the fact is no one really knows what the median water use is for the median sized plant in Emerald Triangle grows because no one has tried to do a real study following standard scientific protocols. You don’t get scientific answers by cherry picking a figure out of a white paper presented to the Humboldt County Board of Supervisors with absolutely no verification of the data in that paper and then ignoring the context of that figure, which is what Scott Bauer deliberately did after he was told he was wrong by more than one person. That’s a classic sign of Bad Science. That turns a scientific study into political propaganda for whatever agenda the California Department of Fish and Wildlife or other bureaucracy chooses.

            The Humboldt Growers Association (now Emerald Growers Association) based the white paper on the Mendocino 99 plant Zip Tie program the feds shut down. The grower’s objective of that program was to maximize bud production within the allowed canopy size. I was told by one of the participants in the white paper that the plants were 7 pound and up producers and that takes exceptional gardening skills to pull off with 6 gallons per day in the hotter climate of Mendocino county.

            But you’re absolutely right Kym, the bottom line as I posted in another comment is that marijuana farmers who divert water from springs and creeks in the summer are partially responsible for the low flows that are impacting salmonids. No one can quantify exactly how much is from the growers, how much is from the drought and how much is from non-marijuana uses (homesteads, ranches and other farming activity).

            • I agree that it isn’t so much science as a working theory. And I think a scientific study would be much better. However, getting one might be too late for the fish. (Heck, it’s probably already too late. Salmon Creek has no salmon and I can’t bear that thought.)

          • It all depends on the size if the plants. Small containers take less water. The numbers are not correct, but they make a point. Lots of water being sucked dry. The point is every single grower uses different quantities of water per day depending on the size of the plants, air temperature and their water supply. Most of the local growers use less than 6 gallons of water per day. That is my educated guess.

    • 6 gal. per plant per day is probably not far off. When full-term outdoor plants are getting mature they can take much more especially on 90 degree days. The 6 gal. number is a fair average over the life of the plant. Full-term outdoor plants can get huge. Dep requires less per plant cuz they are typically smaller… but usually more numerous. Regardless of Bauers estimate, nobody can deny the water sources are being sucked dry by grows. That’s what happens when money grows on trees.

  • They should put together a team to walk the watersheds and take down the grows that are in violation, they seem to be able to put other teams in place for eradications, let’s take it a little deeper and fix the diversions and take action against the violators. Humboldt Strong!

  • Why were only these four areas studied. It would seem to be more instructive if they included the Mattole River in their study. The Mattole has massive water tank storage, that could not only offset water loss, but improve water flow in the fall.

    “The authors warn that marijuana grows are more harmful to waterflow than logging. They state,”
    No sugar Sherlock!…. Why do people forget (Maybe didn’t know) the devastating affects of the Oct ’62 windstorm, or the Dec ’64 Flood?

    • wait a minute....

      They can say its worse than logging today because we have very little industrial logging right now. How about cows vs grows? I love our local dairys but its wrong to not include them in a study of water use. I agree with above comment- why just these watersheds? Why not out 299 where there are incredibly huge scenes? Not including the Mattole makes me think these scientists used watersheds that would prove their hypothesis. The water storage program us awesome- why wouldn’t they include it? I took statistics too, its so easy to throw results off.
      Where is the study of the long term impacts of the often illegal logging? The Maxxam owned PL would pay fines for breaking the law rather than work within the regulations. Did the pot growers fill the eel with sediment so deep the original riverbottom cannot even be reached through it? Nope. The silt causes the water to run underground rather than over it, and the fish have suffered terribly because of it. I know there are people being idiots with water use. The folks I know in the hills spend their earnings on water tanks, developing better springs & utilizing methods to conserve water in their growing practices. If you are watering a plant everyday with 6gallons then you are an idiot. It would most likely kill a plant. Especially in clay soil base. I really wish these studies were done during the heavy logging here. I saw people beg the agencies for these types of studies back then for years to no avail. I would also like to see the effects I of all the poisons used in indoor scenes. From what I hear at least 90% of indoor uses some kind of harmful chemicals, especially for the “new mites” (yes they are here and invisible to the naked eye). The poisons for them are being ordered from colorado and Oregon as they are illegal for use in our state. Um, isn’t that an environmental crime? Seeing powdery white mildew and mites on plants in the forest breaks my heart. They are becoming resistant to treatments due to increased use of poisons.

      • “Did the pot growers fill the eel with sediment so deep the original riverbottom cannot even be reached through it? ”

        The answer is yes they have.
        Just look at what has happened to the S.Fork of the Eel is the last 5 years.
        It is taking 7-10 days longer for the river to clear after a rain.
        I float and fish the S.Fork for 70-90 days during the Winter and have have done so since the 70’s.
        For most of those years,(especially since the advent of the Internet), I have kept records of the river levels and when the rivers clears so I can go fishing.
        I used to be able start fishing from Benbow down when the river level reached 2000CFS(Sylvandale station), now I am lucky if the river is clear enough at 1500CFS, usually much lower.
        The increased sediment has covered many rocks that were visible 5 years ago. River bends are filled with small sticks at silt, so deep that you will sink to your thighs in the muck.
        Many of the mouths of the tributaries that empty into the river are filled with rocks and debris from the excavations in the hills.
        5 years ago, there were 100’s of Kings spawning in Salmon Creek, I have not seen one since. Even if there were Kings in the creek, the spawning gravel is mostly covered in silt, making it nearly impossible for the Kings to spawn.
        The same thing is happening in most tributaries.
        Hardly a day goes by where I don’t see dozens of trucks loaded with soil and 5 or 6 excavators going by to continue removing soil from the hillsides.
        This year, so far is the worst I have seen. Even though we received double the rainfall this year( almost hit our long term average), excavations were taking place during the worst storms.

        • You are seeing what I am seeing.

        • There are millions of miles of skid trails around these parts from the height of the logging era, back in the day most of the roads did not get culverts they would fill in the creeks with dirt and let it wash out, how do you know where that sediment is coming from?

          • First off, there are not millions of miles of skid roads, although there are a lot.
            Most of the old skid roads have, for the most part healed themselves, most of the old skid roads are heavily vegetated with trees.
            It is easy to connect the dots. Up until about 5 years ago, before the massive Industrial type grows started, the river and the tributaries were clearing faster and the creek and river beds were becoming narrower and the alders and willows were growing back to provide shade.
            Now that is all changing and the rivers and creeks are starting to look and act as they did 30-40 years ago.
            About 10-15 years ago, there was a major creek restoration project in Salmon Creek. These people worked on about a mile of the creek that flows though my property. The results were amazing. The creek bed went from being nearly 300′ wide with most of the water flowing underground in the Summer to a creek bed that was 50′ wide and the creek channel was gradually scoured down to gravel.
            Now all that work and tax payer money ha been wasted and the creek is back to being wide,with little shade and sediment choked.
            What changes occurred that made this happen?
            Large excavations, that allow all the soil to wash into the creeks.
            and river.
            I don’t blame pot so much as the methods that some people use to grow it.
            A tremendous amount of soil has to be removed to build 100’s of 100′ plus green houses.

        • I have my own theory on the sedimentation based on the weir/ spring I have tended for almost thirty years now. Ever since the drought started it became silted over. But that was also the year we started having these infrequent atmospheric river events followed by no rain. In previous decades the rain fell over greater periods of time that allowed the silt to move down the conveyer belt so to speak. The super rain events cause silting but without follow up storms the dirt gets stuck.

        • In my watershed the increased road traffic in the past 5 years is a major factor in the amount of sediment being produced. Road maintenance is not keeping up with it, the ditches keep filling with road sediment and that causes more erosion of the road surface.

          Another thing that has changed is the rainfall patterns. We aren’t getting the kinds of big storms in the past 5 years that flush the fine sediments.

          But you’re right Hooktender in your observations of the sediment in the river. I just think the causes are more complex than just pot growers.

  • It’s good that this study was done, now as another said, it is time to take it a step further and get these people OUT of the water shed areas, where they are already trespassing anyway!!! It’s time these people stopped making excuses and denying that they are doing any harm. And don’t change the subject to something else. Let’s stick to this subject/problem. It really really needs to be addressed now more than ever, with the west in such terrible shape with the ongoing drought.

    • I don’t think most of those grows are trespass grows. Those small farms in the hills are mostly owner operated. (Small relative to other agricultural farms.)

      • I have a neighbor/land partner who agreed to an in-house agreement as to a land split. They have trespass grows on my land ( but since it was a division not recognized by the county it cannot technically be considered trespass ) they were not counted at all in the map. So perhaps some of what I consider vast overstatements of plant numbers would average out to his original estimate if all the old mini patches were still being used.. At any rate I feel many people here are ahead of the curve as to how to manage water in cutting edge ways. But that is inherent optimism on my part. I cannot police anyone but myself.

  • Before everyone jumps on this propaganda bandwagon we should see a study on the effects of grapes on the fish, or how much water is used to water every lawn, its easy to point fingers at people that are not willing to stand up for themselves

  • Lazy Skunk Ranch

    What’s scary is when the corps move coming production to the central valley they are going to need to use reverse osmosis water! That’s anywhere from 1-4 to 1-10 in fresh vs wastewater! The salt wastewater will need to be pumped back into the ground because there isn’t much one can do with it.

    Blaming the fish and wildlife decline on growers is pretty silly, as all along the west coast, up into Alaska marine life is dying at a high rate. Some blame Fukushima, who knows what is causing it, but something is going on and if it’s coming from a single source odds are it isn’t growers, it’s something bigger.


    Fall chinook salmon runs strong
    By Pat Higgins

    Eel River recovery Project

    Posted: 12/03/2014 11:45:15 AM PST

    The Eel River Recovery Project (ERRP) 2014 Eel River fall chinook salmon monitoring dives of the lower river are complete, and this year’s run started strong. Thousands of chinook salmon entered the Eel River in late September and October, migrated upstream on rains around Halloween, and are now spawning throughout the Eel River watershed. There was another wave of chinook salmon coming out of the ocean with rains at Thanksgiving, and ERRP will shift its efforts to an inland network of volunteers who watch salmon.

    As in previous years, ERRP focused the most dive effort in pools in Fortuna at and below the River Lodge. After rains in late September lured fish from the ocean, ERRP volunteers estimated that 2,467 chinook salmon were present in three lower Eel River pools on Oct. 11. Interestingly, smaller male or jack chinook salmon comprised about 25 percent of the fish counted. These fish spend less than a year in the ocean and are an indicator that survival from the spawn of 2013-2014 was very good, despite extremely low flows during the spawning season.

    As rains came and high tide cycles coincided, ERRP volunteer Dave Wagner sighted a large school of chinook under Fernbridge on Oct. 19, indicating another major influx. On Oct. 20, the Van Duzen River opened and fish were reported above Carlotta then next morning. At daylight on Oct. 21, there was a mass migration out of Fortuna’s 12th Street pool, and dozens of individual fish could be seen rolling and moving up all day long. Rains continued until the Eel River at Scotia crested at just over 3,600 cubic feet per second (cfs) on Oct. 26. A conservative estimate would be that 5000-10000 early run chinook salmon disbursed upstream by that point.

    This first wave of fish traveled without stopping to areas far upstream, passing spawning areas by that were heavily utilized in 2013. ERRP fish watchers in lower reaches of the main Eel, South Fork and Van Duzen rivers got a misimpression that there were few fish so far in 2014. In fact thousands of fish had moved past them and none had chosen to stop. By the first few days of November, Chinook salmon began to spawn in small numbers, with hundreds more fish holding in pools waiting for the next rains. The run was concentrated between Highway 1 at Leggett and the mouth off Ten Mile Creek on the South Fork, in the Van Duzen from Grizzly Creek to above Bridgeville, in the Middle Fork to below the Black Butte River, and in the main Eel River from Dos Rios to upstream of Outlet Creek. However, the main Eel River immediately below the Potter Valley Project had few fish all the way to Hearst, and none had jumped the ladder at Van Arsdale Dam, as of the third week of November.

    ERRP volunteer coordinator Pat Higgins documented over 800 chinook salmon on Nov. 9, holding in just three pools between Outlet Creek and Dos Rios. A few dozen fish were actively spawning in this reach, but it was a small fraction of the number holding and waiting for rain.

    Two weeks of dry weather then allowed the lower Eel River to clear enough for two additional organized dives. On Nov. 12, a small ERRP dive team of six estimated that at least 500 chinook salmon were holding in the 12th Street pool in Fortuna along with seven green sturgeon to six feet in length.

    The Humboldt Redwood Company led a dive upstream of Scotia on Nov. 19, and the team documented just under 1000 chinook in the four pools surveyed and another green sturgeon.

    Rain from Nov. 21 to Nov. 23, pushed Eel River flows to their highest since spring, and tributaries in the southern extent of the watershed also swelled. Chinook salmon migration began in Outlet and Ten Mile creeks in Mendocino County and fish are now spawning all the way to the headwaters, where cascades and waterfalls block migrations. A number of spawning pairs have been spotted in Willits area creeks.

    Dives and surveys in Mendocino County are paid for in part by a grant from the Salmon Restoration Association, which sponsors the annual World’s Largest Salmon barbecue in Ft. Bragg on July 4 weekend. See for more information and call 707-223-7200, if you want to report on chinook salmon migration or spawning.

    California Department of Fish and Wildlife Biologist Scott Harris said last week he had already counted, measured and marked 300 Chinook salmon passing upstream at the Van Arsdale Fish Station on the upper Eel River. Two years ago a record number of 3,500 Chinook passed this station.

    more @ link

  • This has been a topic of conversation since the 70’s…so Fish and Game, EPA, and god only knows who else is JUST now getting around to actually putting it in a study??? Discussion in Humboldt, once upon a time, a long time ago…Hippie: The area is over hunted. The deer population is down. Redneck reply: They been eating your maryjane plants…don’t want to screw….. Hippie: Noticed the salmon count is down, must be the combination of that dam at Benbow and over fishing. Need a law for catch and release only. Truth behind the low return on Salmon for spawning….All live streams had stumps and logs removed because EPA said it was polluting the streams when in actual FACT (a word not in EPA’s vocabulary) it was supplying shade, depth of water, which supplied cooler waters, and great spawning beds. When you hear a “self-proclaimed environmentalist” say this will be good for you, and/or the environment…know the next words will be lies or to be nice, no facts supporting these ideas. 30+ years and they have just about destroyed the parks eco system, the water streams, and the economy.

  • Besides the inflated gallons per day number I’d like to point out the fact that if you log onto Google earth and view these water sheds most of these “Dots” do not exist.
    The number of grows visible with your own eyes is one tenth of what they have indicated on their maps.
    This is big time propaganda, plain and simple.
    Once this conversation becomes reasonable and factual I believe more people will show a interest.

    • I took an admittedly small sample area and checked. I confirmed all the grows on the map plus saw a few smaller gardens that weren’t marked. I might have disputed some numbers of plants but the discrepancies weren’t large. All and all the small sample seemed reasonably accurate to my eyes.

      • The Scott Bauer CDFW study was done using the older 8/23/12 Google Earth imagery database. If you are looking today the imagery was updated 5/28/14 so things could be different and probably bigger from my spot comparisons.

    • If you had read the study, you would have seen that the authors observed that water usage varied from a little less than 1 gallon/day to a high of 14 gallons/day.
      The 6 gallon/day usage seems about right from my observation. The per plant average varies a lot depending upon whether we a talking about small plants in a light dep vrs. large outdoor growing plants.
      I could not disagree more about your observation that many of the “dots don’t exist, it is actually much worse than the article states, as their survey was done in 2013 and there are many 100’s more gardens and greenhouses now than in 2013.
      Where I live for example, within a mile of my house there are at least 12, 30’x100′ greenhouses built last year and probably more I don’t know about, plus the new ones being built this year.

  • It’s time for disbelievers to take a whole day off from being too stoned to notice how bad it’s become. Yeah, a who–le day… I’m glad to see this study come out. Finally, some empirical data to support what I’ve been saying for years: Pot farms are industrial pollution at its worst! It does not take a genius to figure out that draining water from sensitive environmental areas, and/or causing rampant erosion is going to have a serious detrimental effect on the ecosystem. As a fisherman, this pisses me off! I think CA has too many vineyards too, but at least they have to follow regs that control how much water they use – and the damn runoff! Grow whatever you want, but do it responsibly.

    • All pot farms are not industrial polluters. I’ve been on some beautiful ones that use best practices and then some. However, I’ve certainly seen some horrible examples, too.

  • I agree that it’s less than useful to compare water use of a cannabis plant with that of a grape vine.

    One large plant can produce several thousand grams of usable cannabis; that’s thousands of individual doses. Unless a single vine can produce thousands of glasses of wine, the comparison is misleading.

    Better would be gallons of water / day / unit of consumption (say, .5 grams versus 1 glass of wine).

    Another illuminating comparison would be water / day / wholesale value / unit.

    This is important work, but it is much too easily taken up into anti-pot discourse in ways that seem to make cannabis itself a villain, while grapes, timber, and other products are OK because “at least they follow some regulations.” The problem is that the economic and social positives of cannabis are often not allowed into the conversation.

    I don’t blame environmental scientists for doing the work, but it’s important to contextualize it in multiple ways, and that often doesn’t seem to happen.

  • The Eel is one of the most sediment discharge rivers in the world .Look it up .This is a fact

    • So, what is your point? Are you saying that since the Eel historically has a high sediment load, we should be OK with increasing the sediment?

  • Legal regulations? how bout hack and spray that is legal, just because there are regulations does not mean they are good ones. look at this article the picture in that article is worse than any pot grow you can find

  • This is really gnawing at me. That six gallons a day per plant nonsense has huge implications for industrial hemp. Maybe the single most environmentally happy thing we could do is have hemp growing everywhere and make everything from it. If the PTB pit that figure against our terror of water shortages, DESPITE that it would increase the amount of water available, we’re that much further from sense prevailing on earth.

  • I’ve commented elsewhere for over a year that Bauer’s choice of 6 gallons per day per plant for 120 days is just plain wrong for an average outdoor plant in 3 of the 4 study watersheds. I even told him directly, but he had to make a tough choice and he chose the only documented water use figures he could find and let’s face it, he probably couldn’t have gotten permission, nor funding, to collaborate with legal medical growers to actually measure what a plant needs and at what stage of growth. Therefore his data is thrown off by the way he calculates water usage.

    Personally I’m an advocate of expressing water usage in gallons of water used to produce a pound of buds. That’s how most agricultural water usage is expressed and pick any legal crop and the ag scientists know how much water each unit of measure requires, e.g. it takes 1.1 gallons of water to produce a single almond kernel. It would take a more expensive and thorough study to scientifically measure the water usage of pot plants and account for all the variables of soil, growing climate and type of cultivation (greenhouse, dep, full sun outdoor). I know for myself that a pound of outdoor pot in the middle Mattole Valley is going to use around 300-350 gallons of water to produce.

    Water usage of some of the trespass grows Mourad Gabriel is familiar with was metered and it was higher than I expected. As many know Gabriel is the scientist who is studying the effects of rat poisons on the fisher and other wildlife around trespass grows on National Forest lands. They measured 8 gallons per day per plant at some of the busted trespass grows in August, but we’re talking about plants grown in rocky native soil in much hotter temperatures than Salmon Creek or Redwood Creek in SoHum.

    But all my complaining and quibbling about water usage in Bauer’s study aside, the effects of unregulated growing in our watersheds at the current scale is undeniably a major factor in the survival of young salmonids when coupled with the current drought.

    So the bottom line remains this: No grower should be diverting irrigation water from a creek or spring in the summer. No one should be causing sediment introduction into any stream or river. Landowner groups must invest in better road maintenance and upgrades to reduce sediment pollution from dirt roads. That’s going to take some cooperation within the growing community and so far the clandestine nature of marijuana cultivation does not encourage the level of cooperation needed to protect the streams and rivers. What we have now is every man and woman for themself.

    There’s plenty of water available in our area to grow pot, even in this drought—you just have to collect it and store it in the winter when it is plentiful and will not negatively impact the spawning stream’s habitat.

    One of the potential benefits of Legalization should be bringing marijuana cultivation into the open and sensibly regulated and not overtaxed so that existing regulations and water use can be adhered to and enforced. If the regulations shut out the small growers or overtax it then the Black Market will continue and that will continue to drive illegal cultivation into the hills and we can expect more of the same negative impacts, albeit on a smaller scale.

  • This may be away to a way to fix the illegal grows and land clearing , Sending out fines and pulling illegal water pipes . One problem I see is how far back in time will they go? The county just admitted to a number holes they drilled without permit. It was how it was done in the old days. Buy land put in a pond ,drill a well you were homesteading. I would imagine quite a few ponds and lakes were not permitted. It just got so large now there is a problem. There will be a lot of angry people if they have to fill in a 30 year old pond planted with fish with accompanied flora and fauna. It is a good question why the timber industry got a free pass from the waterboard.

    • The problem is so much bigger that the Water Board and DFW is capable of handling. Look at what they’ve done so far: one inspection sweep through a few properties in Sprowel Creek and since then nothing that has made the news. It took them over a year just to plan that approach. They brought in temporary people from out of the area who didn’t even know the territory they were inspecting nor had any knowledge of how a growing homestead in the hills works. There’s over 4,000 grow scenes in Humboldt county alone—they can’t handle the scope of the problem by going door to door. The system isn’t built to handle it.

      The bureaucracy is simply underfunded, undermanned and obviously without leadership. Their process is hamstrung by their own culture and process. What’s worse is that our problem is probably not even on the governor’s radar.

      This problem must be fixed from within the growing culture through education and peer group pressure.

      • I agree that most of the problem has to be fixed by the growing culture itself. But, I think that reports like this kickstart discussions and I think there some of the worst offenders are not susceptible to peer pressure.

      • Uti you of course are right. My bad to blame just one agency when there are a multitude of alphabet soup agencies that are responsible. We got to move the ball forward today. Looking to blame is like looking in a mirror. We are all in it together. The planet deserves better . I think one of the most interesting thing I have learned since following Kym is that a forest should be viewed as a canopy instead of a corn plant. It takes a forest to grow a Redwood Tree.

  • Yup saying nothing has not been working. I think the scenario that say dope growers are lesser people needs a changed attitude. Farming is a noble task .

  • The water per plant per day is variable. It depends on many factors. What part of the cycle are the plants in? Starts, Vegetated, or Flowering? What is the air temperature? Plants use more water when it is hot and less when it is not. Plants use very little water when they are small starts. During the vegetative stage plants increase water uptake as they fill in their containers. Smaller containers take less water than large containers. Plants in the ground water differently than plants in containers. Container plants dry out quicker than plants in the ground. During the hot summer heavy vegetative stage plants drink a lot of water. The low water flows occur at the same time plants are the thirstiest. The increase in water use continues into the flower stage until the buds begin to ripen. At this stage the water intake decreases, but the air temperature has decreased as well.

    The big problem now is everyone Black Boxes/light deprivation. People are in flower stage literally year round now. What needs to be taken into account is black boxes generally require more plants. With growers pulling off 2 to 3 black box harvests on average a season they are growing 2 to 3 times the number of plants. For example, a full term scene may have 100 very large plants. Those are the plants sucking 6 gallons a day during hot summer days. They are the 5+ pound plants you here rumors about. They suck the most water, because they are in the largest containers or biggest holes in the ground. The bigger the plant the more water it takes to keep it happy.

    On the other hand you have people operating Black Box scenes. They are the long hoop houses seen in photos. The Black Boxes require many more small plants.(yes, some black box large plants, but the majority go for the numbers game. More plants = bigger harvest) In a typical black box in Humboldt County you might see anywhere from 100 to 1000+ plants and that is just the first run. The Black Box growers need to replant, so they have another 100 to 1000+ plants in vegetive stage growing in small containers while their current round is in flower. When they harvest the next round is fully grown and ready to be planted and instantly put in flower stage. While the 2nd round is flowering the 3rd round is vegetating, growing & sucking up more water during the hot summer months. The 3rd round is usually planted right before the full term harvest early buds start to come in(end of Aug./1st of Sept.)
    The typical Humboldt County grower these days is growing full term and at least 1 black box if not multiple. This is the true impact on our ecosystem. The 6 gallon per day per plant is probably correct for 5 pound plants during 100 degree heat. The real problem is not the 6 gallons per plant, but the number of plants the study thinks is being grown. The true number of plants being grown in this region is probably 3 to 4 times the number stated in this article. What also isn’t taken into account is all of the indoor grows scattered throughout the region. You can throw in another @ least100K plants for the indoor grows as well.

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  • I actually helped do an informal study using an inline water meter to check total usage on a select sample. The sample was well protected from wind and had about a four to five o’clock sundown ( east face ). They were in 45 gallon pots. It was monitored to make sure the grass under the pots was not getting to green. The season per day usage was roughly 4.1 gallons. The per pound produced number was roughly five hundred gallons .

    • You’re watering 4.1 gal every day?
      I’m surprised they didn’t get root rot, especially when they were babies.
      Until they get around 3-4′ tall I can’t see them needing more than 2gal every other day, less when they’re babies which probably don’t need more than 1/2 gal every 2-3 days. (at most) From what I’ve heard and by my experience plants shouldn’t be watered everyday and they should pretty much dry out between waterings.

      • Next study I might try some modifications. If I do one. Dialing it back would be a goal. It was sloppy in some ways to start at a point and do follow ups. Drippers and timers can overwater sometimes if not attended to properly. I would like to try a more spaced out planting with better light and a more aggressive dialing up and down of hours to see if it can be lower. No bullshit, just facts. Not everyone is micro managing the timers. Perhaps a hand watering vs. drippers on timers would get better ratios. And as I said, there was very little green grass around the pots telling me it at least was not running out into the surrounding dirt. Feel free to post your own meter based study over an entire full season. I wonder if the dep ratios would be a lot lower.

        • Drippers on timers are ok, that’s the best way to control your water but the drippers you have might be too big, I’d go with 1 gal/hr to start then adjust the length of the time you have them running. The smaller the dripper the better the water is able to soak in instead of running off for one thing, it’s better to water them slowly and deep. If it gets too hot cover them with shade cloth, they like the hot sun for the most part tho as long as you don’t overdo it.
          Also 45 gal pots sound pretty big to me unless they’re some pretty monster sized plants, most of the time 15 gal pots are plenty big enough, you don’t want the pot much bigger than the root ball or you’re just wasting water. In my opinion when it comes to gardening most people are inclined to overwater, they need enough but too much isn’t good for them.

  • According to your sample, it took roughly 500 gallons to produce one pound of manicured weed?

    • It was deliberately a little sloppy and I was not fully in charge of the pound count. But I was on the full season daily average. A little under 15 k gallons for 30 pots. that probably included some wet and mild weather days that could have been skipped. But it also had a harvest date that was cut short due to the second damaging rain.

  • The real issue is stream flow, and the best way to determine stream flow is to measure it. These estimates of the number of plants coupled with estimates of the water use per plant can magnify small errors into major misstatements. Try this:

    100 plants x 6 gallons per day = 600 gallons per day
    90 plants X5.4 gallons per day = 486 gallons per day

    The higher figure is 21% higher, and that’s caused by assuming a 10% overstatement of plants and a 10% overstatement of water uses.

    This study and these figures are going to be used for regulation. Laws are going to be built on it. And the methodology of the study is not solid enough to use for that purpose. It is more like a warning that there may well be a problem, than a statement of how bad the problem is.

    Until stream flow facts are known, the results are speculation, the more dangerous for being clothed in footnotes and scholarly language.

    • Well said. And particularly important for the individual grower. As an overall look at how the watersheds are affected though, I think it is an important step until we can garner specific information. Silverlining’s information is helpful but it gets at the specifics of one case. There is going to be a lot of variety and it will be interesting to look at that as grower’s start weighing in.

  • I’ve done a bit more considering of the study and came up with the surprising, to me, conclusion that the water use of pot plants is not in itself a problem. My calculations, which you are welcome to double check, are that 500,000 pot plants in Humboldt County using 6 gallons a day for 90 days each would require about 828 acre feet of water, and that the Main Eel at Alderpoint, alone, could supply all of that water in less than 2 hours in the height of the rainy season. The problem comes not from the amount of water, but from needing it when its dry. Needing it most when the countryside is driest, in fact. The answer is storage, and the best way of storage is probably ponds. Fill them up in the winter when water’s so plentiful it runs down the driveway, and use them up in the hot dry summer. Any thoughts, anyone?

  • Ponds are the best idea. Though building one takes a permit. and I believe that they add to the taxed value of your land.

    • Thank you for the link, my concern is the lack of information on specifics with the permitting process.
      Many existing ponds are located on rural properties and were constructed many decades ago. These older ponds exist with no registration or appropriative water right. For many landowners the registration process is an appropriate path to legalizing the water diversion. There are three registration classes including domestic use, livestock watering and small irrigation. The registrations for domestic use and livestock watering have a maximum annual diversion of 10 acre-feet while the irrigated use has a maximum diversion of 20 acre-feet. An acre foot of water is one surface acre filled to a depth of one foot and is approximately 325,000 gallons. The only diversions that are exempt from permitting are ponds that store water from springs that don’t leave the property, are filled with groundwater or capture sheet flow and not from a defined channel.
      If a new construction pond falls under the water registration exemptions but you plan on moving 50 yards or more of soil a simple earthmoving permit would be required.
      A dam constructed 25′ feet or higher from existing grade will require engineering and sight inspection along with grading permits.
      If a pond is out of a riparian zone and is filled with rain water you are not obligated to go thru the complicated process provided in your link.

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