It was a well known fact so far, that the Maya built small canal systems. The archeological evidence is very clear about that, there have been found several diggings for irrigation already in the 1970s. This was one fact that spoke for the high developed agriculture of the Maya, who had to fight against poor conditions like heat and wetlands around their settlements, in order to grow the needed amount of plants.
After all, they had to supply big cities with enough food to survive, in the late pre-classic and early classic era. It had been some kind of puzzle so far, how they managed that.
Now however, the archeologists Timothy Beach and Sheryl Luzzadder-Beach amongst others made a discovery in the lowlands, more exact in today’s Guatemala and Belize. They discovered trails of huge canal systems, up to 100km in diameter. They found, that those systems were highly complex and was used to reclaim swampland. The findings suggest, that the digging material was positioned on the area between the canals and thereby created raised acres for the cultivation of Maize, Avocado and grasses that are yet to be identified. This finding provides new insights into the agriculture and especially its irrigation in ancient eras, and how the big cities could be supplied at all.
For those who are interested in the Carbon isotopic ratio method and those who have an account at sciencedirect.com, you can find the abstract and article about that, at sciencedirect.com.