Part of the (water) solution

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The indoor farming industry’s track record of efficient water conservation should be applauded — but we’ve still got some work to do, too.

September 27, 2021

Federal mandates out west foreshadow a worsening water supply situation moving forward.

We’re going to run out of water well before we run out of fossil fuels.

This is a declaration I’ve heard put forth by more than one industry professional this past summer. I certainly am not qualified to say whether or not that’s true, or which one will run out first, but I think it’s safe to say when you overexploit any natural resource — without considering how to replace it — you’re going to eventually get yourself in real trouble. I’d say with some of the major water cuts hitting the U.S., we are probably already there.

The U.S. federal government handed down its first federal mandatory water cut in August to the Colorado River, with farmers in Arizona taking the biggest hit. Lake Mead, the reservoir created by the Hoover Dam on the Colorado River, hit a record low water level in August of 1067.57 feet above sea level (August 18th, 2021, according to This is not to say a water crisis is a new phenomenon: property owners across many states, especially Texas and California, have long been under irrigation and other water-use restrictions on a seasonal basis. But those restrictions have fallen under state or local authorities. Now that the feds are getting involved, perhaps the general public will start to pay closer attention to the seriousness of the issue, especially when it becomes more obvious that our food supply is in peril.

If you’re familiar with the “peak oil” theory, then you may have also heard of the parallel “peak water” theory. Just like we rely on fuels generated from fossils, much of modern agriculture also primarily relies on “fossil water,” which comes from naturally occurring underground reservoirs, or aquifers, which may or may not be naturally replenished. Either way, if you’re taking water out of aquifers faster than it can be replenished (if it can be replenished), you’re still in trouble. Sure, unlike fossil fuels, some sources of freshwater are renewable in terms of ecological availability. But our growing populations and their need and demands for water continue to increase non-renewable use, which inevitably leads to non-renewable use of water resources. Not to mention the increasing threat of corporatization of water ownership and rights.

So, can hydroponics save the world’s water? We know that growing food hydroponically already saves anywhere from 70-90% of water use from the get-go. Some growers claim they are managing an impressive 95% reduction in closed recirculating systems, versus water use in field crops. Others claim retention of 97% of their wastewater using closed-circuit desalination (CCD) and reverse osmosis (RO) systems. It’s impressive technology, but it does require a substantial investment and patience on ROI for the cost.

“...we are already struggling to water agricultural crops now, how do we expect to do so for billions more in the near future?”

If you are growing in container culture in your greenhouse, then water reclamation and recycling obviously gets more complex and the infrastructure needs become more challenging, especially if you are trying to retrofit existing structures. If you’re a large operation, tail water recovery systems may work better for you, while smaller greenhouses can potentially use flood and filter floors. Unfortunately, there is no one-size-fits-all solution given the individual dynamics of any given greenhouse structure. Every job is a custom job.

Nevertheless, water shortages will force the entire industry to innovate and adapt. Given the U.S. has about 5% of the world’s population, but uses as much water as China or India, mostly to grow food for export to the rest of the world, greenhouse food growers have both a unique ability — and responsibility — to lead the country in water recycling and conservation efforts … complexity and costs aside, it’s the direction in which we all need to move.

Feeding people is, of course, the main driver of agriculture. Yet, the more of us there are, the harder that gets. The human population is expected to hit 9.2 billion by 2050, with water demands expected to be up by 55% by that year. If we are already struggling to water agricultural crops now, how do we expect to do so for billions more in the near future? Personally, I don’t think we have any business populating the world to that degree. Making sure women have equal rights and domain over their own lives is ultimately the place to start on that issue. But as it stands, there doesn’t seem to be any slowing the population growth any time soon.

Projections of “peak population” have evolved over the years, from the 2004 United Nations Department of Economic and Social Affairs report that predicted world population would peak at 9.22 billion in 2075 then settle out to about 9 billion. In 2014, the United Nations Population Division projected a less optimistic number of 11 billion by 2100 with no declining trend thereafter. Fast forward to 2020, and the Global Burden of Disease Study offered a population peak of 9.7 billion in 2064, with a decline to 8.8 billion in 2100; but that potential decline is directly tied to the advancement of women’s rights, globally.

So, we can talk about water shortages and conservation, as well as reclamation and recycling technology all day long. But unless we’re also willing to couple those conversations with action to ensure women’s rights — and basic human (non-corporate) rights to water access — we aren’t addressing a major root issue of the population, and water consumption, problem.

Leslie (CPH) owns Halleck Horticultural, LLC, through which she provides horticultural consulting, business and marketing strategy, product development and branding, and content creation for green industry companies.