When “Mad Max: Fury Road” premiered in 2015, no one suspected it might actually be a documentary. OK, OK, maybe not a documentary—but the threat of civilization run amok by lack of water and resources is becoming a plausible reality.
The world is, undeniably, facing a water shortage crisis: Currently, 844 million people globally live without clean drinking water. In 2018, Cape Town, South Africa, was projected to be the first major city to completely run out of drinkable water. Severe water rationing limiting citizens to 13 gallons of water per day prevented the disaster, but the situation is still precarious. (In contrast, Americans use between 80-100 gallons of water per day.) At a 2019 conference, Sir James Bevan, chief executive of the Environment Agency, projected that England will face a water shortage within the next 25 years. In both cases, population growth and climate-change-associated droughts have led, or will lead, to a lack of safe water.
Growing population strain can often be met with simple action. In England, Bevan believes curbing use by a third and reducing leaks by 50 percent could prevent the nation’s water shortage.
In the United States, water shortages are more complicated. While areas of the arid Southwest are facing increasing droughts and vanishing water sources, the answer may not be as simple as tightening those taps. Approximately 80 percent of the nation’s consumptive water use (90 percent in some Western states) is put toward agriculture. Globally, as of 2014, about 70 percent of freshwater is used for farming.
In traditional agriculture, a huge amount of water is needed to grow some crops. In California, alfalfa (used to feed cows) is the most water-expensive crop, requiring more than 1,600 billion gallons of water annually.
Agriculture irrigation can also be wasteful. At the World Water Forum hosted in Mexico City, Ute Collier, of the World Wildlife Fund said irrigation systems in some areas may only be 30 to 40 percent efficient. Dams are often built in areas with inefficient irrigation systems or without access to natural water sources, but dams too contribute to the problem. A study published in 2019 showed that dams increase the perception of a plentiful water supply, leading communities to use more water than they should due to the “false sense of abundance.”
We need to find a better way to feed the world and conserve our water in the process. And we might already have an answer.
Fighting water shortages with water
Enter hydroponic farming. Unlike traditional soil-based planting, hydroponic systems use a small pump to provide plants with water straight to their roots, where an inert substance—such as coconut fiber—supports the root base of the plant. Plants are fertilized with a mineral-based solution to ensure they receive the proper nutrients that are typically imparted from the soil.
The system is sealed in a container that recirculates water usage to the root system with minimal waste. The water that isn’t absorbed by the plant’s root system ends up back in use, leading to minimal loss of water through runoff (though a small percentage evaporates). And while runoff water in traditional agriculture can carry pesticides or other contaminants that make their way into groundwater and drinking water, further polluting the fresh drinking water, hydroponics are grown in controlled environments with no need for pesticides.
Because the system is sealed and minimal water is lost during the farming process, plants can thrive in fairly arid conditions and can be packed closer together than in traditional farming. Even better, hydroponic farming uses about 10 times less water than field crops, according to a researcher working with the University of Arizona’s Controlled Environment Agriculture Center. In addition, hydroponic farms can yield up to 1.7 times the produce per square foot over traditional agriculture and lead to faster harvests, sometimes cutting harvest time in half (depending on the crop and efficacy of the hydroponic setup).
Taking cues from the past
Hydroponic farming isn’t a new invention. The earliest recorded usage of hydroponic farming was in the Hanging Gardens of Babylon, considered one of the seven wonders of the ancient world, built around 600 BCE. The Floating Gardens of Xochimilco built by the Aztec—a 1,000 year old hydroponics system—are still standing in Mexico City. Marco Polo recorded instances of hydroponic farming when he traveled through China in the 13th century.
And in the 1930s, Pan American Airlines grew vegetables using a hydroponics system to feed pilots and passengers stopping at a fueling station in the remote Pacific Ocean atoll of Wake Island. Finally, in a more contemporary—albeit fictional, though still possible—space, the 2015 film “The Martian” features the use of hydroponic farming on Mars when the main character is stranded there.
Back on Earth, hydroponics farming offers the chance to eat well, locally. As hydroponic farms don’t require expansive soil fields, for urban dwellers in particular, the practice offers the chance to eat something produced practically next door. Urban Growth, a nonprofit organization in San Diego, California, specializing in hydroponic farming, aims to increase access to fresh, local produce with little water waste by setting up urban Micro- and MacroFarms.
MacroFarms can reach underserved communities
Urban Growth’s current MacroFarm is located on a rooftop in downtown San Diego, steps away from Petco Park, home of the Padres. The MacroFarm measures approximately 12 feet long by 6 feet wide, although there’s also a smaller, vertical garden in a closet on the rooftop where seeds sprout before they’re transferred to the outdoor area. According to Ivan Corona, cofounder of Urban Growth, within the last 15 months, the MacroFarm has yielded eight harvests, with each harvest producing between 40 and 60 pounds of leafy greens.
For the MacroFarm, Urban Growth partnered with Alpha Project, a nonprofit serving the homeless population of San Diego, to use space on the rooftop of a building providing low-cost housing to formerly homeless people in the area. The people who live at the Alpha Project housing are allowed to keep whatever produce they harvest—as long as they work in the MacroFarm.
Workers often spend a few sunny hours checking the progress of seedlings and transferring plants from their beginnings in the indoor portion of the Urban Growth MacroFarm to the larger farm outside. “We like being near places like this—we want to start with people with the least access to fresh food and farming,” says Alison Aragon, board member at Urban Growth.
Maintaining connections with those in need is key for the nonprofit. “This is our way of giving back to cities, the community, our planet,” Corona says. “It belongs to everybody.” But they also have a much larger vision for a MacroFarm in mind. The goal, within the next five years, is to find space to build a much larger MacroFarm in downtown San Diego, one that could grow enough produce to serve as a local farmer’s-market-cum-food-cooperative for the community. Corona envisions a MacroFarm where those who live downtown could stop by after work to see where the lettuce, herbs, and other produce being harvested are growing.
It would allow urban dwellers the opportunity to buy local—as in, just-down-the-street local. “If you have the option, why not buy local?” Vaughn asks. Because hydroponic farming doesn’t require the use of pesticides, you also know you’re eating clean. “Soap and oil are the only pesticides we ever use. We could spray the produce the day of harvest, and it’s safe to wash and eat immediately afterwards,” Corona says. Considering the United States uses about 1 billion pounds of pesticides per year and that 16 percent of pesticide users have reported pesticide poisonings or unusually high pesticide exposure, that’s no small detail.
MicroFarms spread knowledge of hydroponics
But hydroponics aren’t limited to rooftop gardens. Nearly anyone can have one. A MicroFarm can be as small as a personal hydroponics system growing a single plant—perhaps basil, cilantro, or lavender. MicroFarms can be maintained by an individual fairly easily; the plants need about six hours of sunlight a day, minimal water, and little oversight.
Urban Growth hosts workshops on MicroFarm basics. These workshops show San Diegans how hydroponic farming works and encourages participants to start their own seedlings.
The nonprofit also does extensive work in local schools. Kolby Vaughn, one of the co-founders of Urban Growth, estimates that the organization has worked with approximately 20 classes and 800 children in the San Diego area. Students are given a hands-on opportunity to grow their own plants in a MicroFarm and learn more about how hydroponic farming works. “We see intense enthusiasm in the classroom—students are so excited to share their projects. They get to see growth every day,” Vaughn says.
MicroFarms are a good introduction to the world of hydroponics, and they help shift public perception toward alternative methods of farming from traditional agriculture. But MacroFarms offer the possibility of real change to San Diego and beyond.
The true global benefits of hydroponic farming will emerge when systemic change to the agricultural systems occur, not from a shift in how we grow individual basil plants for our summer caprese appetizers. A shift toward hydroponics is on its way in some global communities: Guangzhou, China, has been harvesting hundreds of pounds of produce grown via hydroponics from rooftop gardens to help feed its residents and test whether or not hydroponics farming might help feed the country. Lufa Farms, a rooftop hydroponics greenhouse in Montreal, delivers 10,000 baskets of produce each week to consumers throughout the area.
And the idea is starting to become so mainstream that Ikea introduced a line of home hydroponic cultivators in the United Kingdom. While those home hydroponics from Ikea aren’t going to lead to the systemic change we need to conserve water, they signal a shift towards making hydroponics farming more mainstream and understood. Maybe we can still avoid that “Mad Max” future, after all.