California’s commercial cannabis laws, as established
through the Medicinal and Adult Use Cannabis Regulation and Safety
Act (MAUCRSA), have always contained the acutely problematic
provisions of so-called local control as well as the express
exclusion of cannabis from the California Environmental Quality Act
(CEQA) exemptions endowed to all other agricultural crops. This has
created an unworkable dynamic for California’s legal cannabis
mixed light and outdoor cultivators who are uniquely vulnerable to
baseless claims of excessive water use. Such claims are routinely
deployed as a trojan horse by those ideologically opposed to
cannabis legalization in order to prevent the permitting of
specific projects, as well as to obstruct the effectuation of
necessary local ordinances.
In order to really understand the speciousness of these
arguments, it is important to evaluate the water use of other
agricultural activities in California. As a baseline fact,
agricultural activities are the primary consumer of water resources
in California,accounting for approximately 80% of all
water used for businesses and homes in the
state.1 Since the scale of consumption is so vast,
common units like gallons and liters don’t suffice to measure
water use. Instead, agricultural water use is often measured in
An acre foot is the amount of water required to cover one acre
of land up to one foot. This is equivalent to 43,560 cubic feet or
325,851 gallons of water; or roughly half an Olympic sized swimming
Cannabis cultivation, like almost all other agricultural
activities, consumes water. However, cannabis actually uses a
relatively small amount of California’s water when compared to
the average water consumed to grow an acre of California’s
other major agricultural crops.3
Average Acre Feet of
Water Required to Cultivate One Acre of Various
Figure 1: Average acre feet of water, shown to approximate
scale, required to cultivate a single acre of various crops in
The Scale of Cannabis Cultivation
An examination of cannabis’ water usage doesn’t stop at
scrutinizing the average acre feet of water required to cultivate
an acre of cannabis and other important crops in California. To
reveal the entire picture, we must look at the scale of cultivation
of each crop.
As of August 19, 2021, there were only 8,081 active cannabis
cultivation licenses issued in
California.4 Assuming ALL 8,081
licensees are cultivating the maximum permissible area, which is a
likely overestimation, we calculated a maximum cultivated area of
2,078 acres.4 Even with this likely overestimation of
cannabis farm canopy, this is still a paltry amount of acreage
relative to other agricultural activities.
For reference, the assumed 2,078 acres of legal cannabis
cultivation is approximately twice the size of Golden Gate Park in
San Francisco or half the size of Griffith Park in Los
Perhaps, the comparison to other crops is more illustrative.
California cultivates approximately 1 million acres of alfalfa,
which is predominantly used for livestock feed.6
California also cultivates approximately 830,000 acres of irrigated
pasture.6 For perspective, this total area-1,830,000
acres-represents an area 60 times the size of the City of San
Francisco. And this is just the land area used to grow alfalfa and
irrigated pasture for livestock.6
California also devoted over 1,260,000 acres to almond
cultivation in 2020.7 This area
is nearly as big as all of California’s state parks
combined.7 In 2020, Grapes were cultivated on 895,000
acres: an area that easily dwarfs Yosemite National
Again, California, even with the likely over estimation of plant
canopy as described above, only has 2,078 acres of licensed
cannabis canopy. This is 0.1% of the irrigated land used to grow
alfalfa and pasture for livestock.
Total Land Under
Cultivation Of Various Crops in California
Figure 2: Land area (acres) under cultivation of various crops
in California, shown to scale.
The Water Used By California’s Cannabis Industry
California’s legal and regulated cannabis industry only uses
a small amount of water relative to other agricultural activities.
Based on our calculations, alfalfa and irrigated pasture
cultivation in California uses about 8,403,000 acre feet of water.
This is 16 times the entire water usage of Los Angeles.9
Similarly, in 2020, almond cultivation, another huge consumer of
California’s agricultural water, used about 4,914,000 acre feet
of water. This is more than the volume of Lake Shasta (4,552,000
acre feet), California’s largest freshwater
reservoir.9 Assuming an average 1.4 acre feet of water
required to grow an acre of cannabis (Figure 1), California’s
legal cannabis canopy consumes approximately 2,909 acre feet of
water or 0.03% of the water used by alfalfa and irrigated
Total Water Consumed By
Various Crops in California
Figure 3: Annual water usage (in acre feet) of various crops as
well as the City of Los Angeles, shown to scale.
 Agriculture Consumes a
Majority of California’s Non-Environmental Water
In California water is shared across
three main sectors: environmental (~50%), agricultural (~40%), and
10% urban. More than nine million acres of farmland are irrigated
in California. This represents roughly 80% of all water used for
businesses and homes, i.e. non-environmental needs.
 An Acre Foot Compared to the
Volume of an Olympic-sized Swimming Pool
An Acre Foot is 0.49 times the volumes of
an (official) Olympic-sized swimming pool.
|Volume (Cubic Feet)||Volume (U.S. Gallons)|
|Olympic Swimming Pool||88,000||660,000.00|
Table 2: An Acre Foot Compared to an
Olympic-sized Swimming Pool
Internationale De Natation). (2021). (publication). FINA
Facilities Rules. Facilities Rules 2017 – 2021. Lausanne,
Switzerland. Retrieved from: https://resources.fina.org/fina/document/2021/01/19/c81a714a-022d-4622-ab8b-b22e95eb2be3/2017_2021_facilities_28012020_medium_ad.pdf.
 Average Acre Feet Required to
Cultivate An Acre of Various Crops in California
- Cooley, H. (2015). (rep.). California Agricultural Water
Use: Key Background Information (pp. 3-4). Oakland, CA:
Pacific Institute. Retrieved from https://pacinst.org/wp-content/uploads/2015/04/CA-Ag-Water-Use.pdf.
- Ingraham, C. (2019, April 26). Forget almonds: Look at how much
WATER CALIFORNIA’S pot growers use. The Washington Post. https://www.washingtonpost.com/news/wonk/wp/2015/06/26/forget-almonds-look-at-how-much-water-californias-pot-growers-use/.
- Johnson, R., & Cody, B. A. (2015). (rep.). California
Agricultural Production and Irrigated Water Use (p. 18).
Washington, D.C.: Congressional Research Service. Retrieved from https://sgp.fas.org/crs/misc/R44093.pdf.
- Martin, A. (2018, February 14). Conservation is key for
cannabis cultivators. Ceres Courier – Ceres Courier. https://www.cerescourier.com/news/local/conservation-is-key-for-cannabis-cultivators/.
- Pera, M. (2021, July 1). Which California crops use the
Most water? Santa Rosa Press Democrat. https://www.pressdemocrat.com/article/specialsections/these-are-the-california-crops-that-use-the-most-water/.
 Cultivation Area (Canopy
Size) of All Active California State Cannabis Cultivation
To calculate the total area devoted to
cannabis cultivation in California we downloaded a list of all
active, about to expire, and expired but pending renewal
cultivation licenses from the Department of Cannabis Control’s public
database. Based on state regulations, licensees are allowed to cultivate a
maximum area based on the type of license. (See table
|Cannabis Cultivation License||Maximum Permitted Canopy
|Specialty Cottage Outdoor||Up to 25 mature plants. [2,500 sq
|Specialty Cottage Indoor||500 sq ft|
|Specialty Cottage Mixed-Light Tier 1 and 2||2,500 sq ft|
|Specialty Outdoor||5,000 sq ft|
|Specialty Indoor||5,000 sq ft|
|Specialty Mixed-Light Tier 1 and 2||5,000 sq ft|
|Small Outdoor||10,000 sq ft|
|Small Indoor||10,000 sq ft|
|Small Mixed-Light Tier 1 and 2||10,000 sq ft|
|Medium Outdoor||1 acre (43,560 sq ft)|
|Medium Indoor||22,000 sq ft|
|Medium Mixed-Light Tier 1 and 2||22,000 sq ft|
|Nursery||[21,780 sq ft]**|
|Processor||[0 sq ft]***|
Table 3: Maximum permissible canopy area
depending on type of California cannabis cultivation license.
* The regulations don’t specify a
cap for maximum area for Specialty Cottage Outdoor
cultivation; instead they limit cultivation to 25 mature
plants. Based on the area of Speciality Outdoor licenses which are
capped at 50 mature plants or up to 5,000 square feet of canopy, we
assumed 100 sq ft per mature plant and designated a maximum canopy
size of 2,500 sq ft for Specialty Cottage Outdoor
** The regulations do not define a
maximum canopy size for nursery licenses, as nurseries don’t
grow plants to maturity. For the purposes of estimation, we are
assumed a generous 1/2 acre (21,780) for each active nursery
*** Processor Licenses are for
cultivators that only
trim, cure, dry, grade, package or label cannabis. As such, we have
assumed zero square feet for permitted canopy size for processor
 California’s Legal Cannabis
Acreage compared to popular city parks in the State.
California’s Legal Cannabis
Acreage, 2,078 acres, is 0.49 times the area of Griffith Park
(4,217 Acres) in Los Angeles and 2.02 times the area of Golden Gate
Park (1,027 Acres) in San Francisco.
|Griffith Park, Los Angeles||4,217 Acres|
|California’s Legal Cannabis Canopy||2,078 Acres|
|Golden Gate Park, San
Table 4: California’s Legal
Cannabis Acreage compared to popular city parks in the
 Alfalfa and Irrigated Pasture
According to the University of California,
“about 1,000,000 acres of alfalfa are irrigated in California.
This large acreage coupled with a long growing season make alfalfa
the largest agricultural user of water, with annual water
applications of 4,000,000 to 5,500,000 acre-feet.” Per the California Agricultural Production and
Irrigated Water Use report published by the
Congressional Research Service in 2015, California irrigates over
830,000 acres of pasture.
 California’s Almond Crop
Per California Department of Food
and Agriculture’s 2020 California Almond Objective Measurement
Report, in 2020 California’s almond acreage totaled
1.26 million bearing acres.
California has 280 state park units
(including state parks, state recreation areas, state historic
areas and state beaches) with an approximate area of 1.56 million
acres. Of these 280 park units managed by the California Department
of Parks and Recreation, 88 are officially designated as
“state parks”, with an area of approximately 1.16 million
acres. Anza-Borrego Desert State Park, the largest state park in
California, is approximately 585,930 acres.
|All 280 California State Park
|2020 California Almond Crop
|California Park Units classified as
|Anza-Borrego Desert State Park (Largest
State Park in California)
Table 5: California’s Almond
Acreage Compared to Area of California’s State Park
 California’s Grape Crop
Per California Department of Food and
Agriculture’s Grape Acreage Report, in 2020
California’s grape acreage totaled 895,000 acres. Of these
895,000 acres, “wine-type grape acreage [was] estimated at
Yosemite National Park, one of
California’s largest and most famous National Parks, by
comparison is only 759,620 acres.
9. Total Water Usage by Crop
To calculate the total volume of water
used by each crop, we simply multiply the average acre feet of
water required to cultivate one acre of each crop (Figure 1) by the
total area under of that crop under irrigated cultivation (Figure
It is important to note that these
figures are gross water use per crop. Net water use – the volume of
water consumed by the crop, minus runoff and ground seepage – is
often lower than the gross water used.
For reference, Shasta Reservoir is
California’s largest man-made lake with a gross pool storage
capacity of 4,552,000 acre-feet. The city of Los Angeles with the
population of nearly 4 million people used 521,915 acre feet of
water in 2018.
Originally published August 25, 2021
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