We can’t deny it. We are in extreme weather. Climate change is here and may be here to stay. And in California that means drought. It also means drought in parts of Colorado and the Pacific Northwest – all legal cannabis states.
“Nations have delayed curbing their fossil-fuel emissions for so long that they can no longer stop global warming from intensifying over the next 30 years, though there is still a short window to prevent the most harrowing future, a major new United Nations scientific report has concluded.”
“In recent years, scientists have also been able to draw clear links between global warming and specific severe weather events. Many of the deadly new temperature extremes the world has seen — like the record-shattering heat wave that scorched the Pacific Northwest in June — “would have been extremely unlikely to occur without human influence on the climate system,” the report says. Greenhouse gas emissions are noticeably making some droughts, downpours and floods worse.”
“Drought is not unnatural for California. Its climate is predisposed to wet years interspersed among dry ones. But the climate crisis and rising temperatures are compounding these natural variations, turning cyclical changes into crises.”
As a society everybody has to do their part to conserve water and be mindful of use. Agriculture is 80% of water use in California. One might ask what that industry is doing to conserve water. There are crops that require excess amounts of water like rye, almonds, and alfalfa.
In an analysis done on the most water intensive crops in California the results are as follows:
“A Pacific Institute analysis of California Department of Water Resources data sheds light on the state’s top 10 water-intensive crops in 2015, the most recent year for which the department has published water-use estimates. The department grouped crops into 20 categories when reporting water-use data.”
“On average, California crops used 2.97 acre feet of water per acre that year, the data show. An acre foot is equal to about 326,000 gallons, or enough water to cover an acre of land 1 foot deep.”
“The analysis ranked pasture first among California’s top 10 most water-intensive crops, in some cases grouped by categories (in average acre feet of water applied per acre in one growing season), followed by nuts and alfalfa:
- Pasture (clover, rye, bermuda and other grasses), 4.92 acre feet per acre
- Almonds and pistachios, 4.49 acre feet per acre
- Alfalfa, 4.48 acre feet per acre
- Citrus and subtropical fruits (grapefruit, lemons, oranges, dates, avocados, olives, jojoba), 4.23 acre feet per acre
- Sugar beets, 3.89 acre feet per acre
- Other deciduous fruits (applies, apricots, walnuts, cherries, peaches, nectarines, pears, plums, prunes, figs, kiwis), 3.7 acre feet per acre
- Cotton, 3.67 acre feet per acre
- Onions and garlic, 2.96 acre feet per acre
- Potatoes, 2.9 acre feet per acre
- Vineyards (table, raisin and wine grapes), 2.85 acre feet per acre”
Cannabis is not on the list. The Department of Water Resources did not track cannabis in this analysis but “The Washington Post reported in 2015 that the crop uses 1.4 acre feet per acre”. It seems that weed is not as thirsty as other crops. But it is thirsty and does use water.
What is noteworthy is that indoor cannabis producers are taking matters into their own hands in conserving the water they do use to grow the sacred bud. Indoor growers are “implementing water-efficiency technologies that maintain enough water for their growing season while ensuring they are responsible stewards of the environment”.
“Adopting long-term water-efficiency measures must be the answer to show leadership in an industry that – right or wrong – has had a reputation for water overuse.”
““We’re building (production technologies) so we’re prepared, from both a fiduciary and a corporate responsibility standpoint, if there’s an issue with water use,” said Jigar Patel, co-founder and CEO of San Francisco’s NorCal Cannabis.”
One method of conservation the indoor growers are implementing is called retention ponds. Retention ponds “secure quality groundwater that can be cleaned and recycled”.
There are two types of ponds that hold water: retention ponds and detention ponds. Both have different functions. One is short term and the other is long term.
“Two different kinds of ponds are often used for flood control and stormwater runoff treatment: wet ponds and dry ponds. Both systems function to settle suspended sediments and other solids typically present in stormwater runoff. Wet ponds are also called retention ponds and they hold back water similar to water behind a dam. The retention pond has a permanent pool of water that fluctuates in response to precipitation and runoff from the contributing areas. Maintaining a pool discourages resuspension and keeps deposited sediments at the bottom of the holding area.”
“Detention ponds are more common in the arid west and serve as important flood control features. They are usually dry except during or after rain or snow melt. Their purpose is to slow down water flow and hold it for a short period of time such as 24 hours. Urban areas rely on these structures to reduce peak runoff rates associated with storms, decreasing flood damage.”
The drought not only affects “access” to water it also impacts the “quality” of the water.
“Drought not only threatens water access but also impacts water quality, according to the U.S. Geological Survey and California Water Resources Control Board, which published a joint study this month reviewing 30 years of data from California’s agriculturally dense Central Valley.”
“Researchers found that because water in aquifers is accessed more often during drought, shallow groundwater – which is often contaminated by agricultural runoff – is pushed into the aquifers, and the cycle continues as drought intensifies.”
For those readers who do not remember their 7th grade earth science an aquifer is porous rock or sediment that holds groundwater.
“To secure quality groundwater that can be cleaned and recycled, while mitigating dependence on groundwater, cannabis producers are increasingly using ag retention ponds.”
According to a study on retention reservoirs released this week by Ohio State and Clemson universities, these resources are effective for:
- Extending water resources.
- Reducing adverse effects on the environment.
- Capturing stormwater to water.
- Reducing reliance on surface and groundwater.
- Mitigating contaminants in water before discharge.
However there are jurisdictions that restrict businesses from collecting rainwater. When that happens the business has to get inventive and turn a retention pond into a detention pond. Here is one business in Colorado that did just that:
““When we did our expansion of the greenhouse, our county no longer allowed retention ponds, so we had to change and rebuild our pond to be a detention pond,” said Aaron Van Wingerden, CEO of Dutch Heritage Gardens in Colorado Springs, Colorado, which produces hemp genetics and young plants and got its start in ornamental plants.”
“Dutch Heritage Gardens pumps water from an aquifer, then uses a detention pond to supplement its water supply. (A detention pond is different from a retention pond because it holds water only for a short period of time.)”
“The detention pond also helps to reduce peak storm flows and flooding and prevents runoff.”
““Anything the plants don’t use, we have concrete and webbing of PVC into the concrete that diverts all the unused water into a series of concrete chambers,” Van Wingerden said. “We clean it and then recycle it and reuse it again.””
“The system has increased water efficiency by 30%, he said.”
Other methods of water conservation are automated irrigation systems which include “ebb-and-flood floors which water the plants from below”, “run-off recycling systems which are water and fertilizer filtration mechanisms that clean water and reduce pathogens”, and “capturing condensate”.
““With ebb-and-flood floors … you’re adding at least $4 or $5 more per square foot greenhouse, but it gives you that freedom to push water back out into the bays and flood the floors,” Van Wingerden said.”
“NorCal Cannabis, which operates six indoor cultivation facilities between Santa Rosa, California, and San Francisco, has invested in technology that reduces its water use by an average of 30%.”
“Netafim’s NUF runoff recycling system, a water and fertilizer filtration mechanism that cleans water and reduces pathogens, allows NorCal to reuse wasted water and any fertilizer present, which also helps decrease the company’s fertilizer use by 50%-70%, according to Patel.”
“But a technology under development in NorCal’s new 70,000-square-foot facility in Santa Rosa will drive the company’s water efficiency to another level, creating a closed loop by capturing the condensate from the operation’s dehumidifiers, Patel said.”
““Between the two technologies, we believe we can get somewhere between 80% and 90% reuse of the water,” Patel told MJBizDaily.”
When plants are irrigated, the system captures at least 30% of the runoff that comes off the plants, but the new technology also allows NorCal to capture the humidity that the plants transpire.
And of course there is cannabis cultivation software to remind the grower when to water the thirsty plant if they don’t want to set the timer themselves.
“In addition to recapturing and reusing water, NorCal uses a crop-steering production platform called Aroya, which allows growers to create recipes and use sensor technology to better understand when the crops need water, Patel said.”
Now wouldn’t it be great if we could set the timer on when it would rain. Wishful thinking.
Author: Sherri Margolin (Dark Matters)