One of today's most innovative forms of sustainable farming is old. Like, really, really old. Aztec Empire old: chinampas.

With all the focus we put on technology, it's easy to believe that sustainability is a new-age idea. Scientists are frantically trying to develop something to save the world from our recent mistakes — the pollution of the Industrial Revolution, spills from any number of oil companies, and the human-made climate change that scientists only began to notice in the late 1900s.

In reality, one of the most innovative farming solutions has been here all along. Sustainable farming isn't a 20th century invention. It's something the Aztecs started doing centuries ago called chinampas.

The Aztecs used stunning floating gardens — otherwise known as chinampas — to grow their crops without harming the environment.

Photo by Karl Weule/Wikimedia Commons.

Chinampas were created by piling mud and decaying plants into small stationary islands on top of which the farmers would sow maize, beans, chilies, squash, tomatoes, and greens. Farmers would also grow the colorful flowers used in a variety of their ceremonies. To stabilize the islands, sturdy reeds were bound together and used to both border each chinampa and to help anchor it to the ground.

The dredging of the mud cleared the way for canals and naturally reinvigorated the nutrients in the soil that fed their crops. The resulting system of canals and gardens created a habitat for fish and birds, which helped maintain the health of the ecosystem and also provided additional sources of food.

The chinampas didn't harm the environment — they enhanced it.

"Floating Gardens" drawing by Internet Archive Book Images/Flickr.

This wasn't just a feat of incredible gardening — chinapas took a lot of complicated work to create.

Chinampas are sustainable, but they aren't self-maintained. Farmers had to construct a series of systems and processes to keep their people and the land healthy. Drainage systems were added to avoid flooding during the rainy season.

To fertilize the gardens, they developed a waste system to collect human excrement from the cities and spread it over their crops. The result was more than just flourishing crops: The chinampas actually helped prevent waste from entering and poisoning the water supply.

The fact that Aztecs found a way to turn unworkable swampland into a flourishing garden is an accomplishment in itself. Even more impressive is the amount of organized manpower, planning, and utilization of their resources required to make their idea a reality.

A chinampa in Mexico City. Photo by Emmanuel Eslava/Wikimedia Commons.

So don't call it a comeback. Chinampas have been here for years.

They're still in place around Mexico City, where they're both a tourist attraction and a working farm maintained by the locals. Other cities and countries have picked up on the chinampa idea, too — you can find them on the Baltimore waterfront and even cleaning up New York's polluted Gowanus Canal.

Some ecological companies have even taken elements of the Aztecs' methods and used it to create new technology that resembles the ancient version of the floating gardens. The sustainability benefits still appeal to modern gardeners — especially since chinampas can grow plants, clean and conserve water, and don't require large swaths of land.

A modern iteration of the Aztecs' original chinampa method. Photo by EZGrow Garden.

The success of chinampas is a testament to the fact that sometimes the most innovative solutions don't involve looking to the future, but to the past.

The incredible efficiency of this indigenous gardening method serves as a reminder that sustainability doesn't have to be expensive or rely on the most advanced technology available to us today.

Sometimes, the best thing to do is to look backward — toward the people who figured out how to do it right the first time.