The Mystery Behind How Guatemala's Lake Atitlan Keeps Rising

Submerged and half-submerged buildings dot the shoreline, in some places appearing as ghostly sunken structures shimmering in the afternoon light. The dock at San Pedro La Laguna is one of the best places to see how the lake has been rising, with a whole row of houses and shops visible under the water as you step off the boat.

Guatemalans and foreigners alike who bought land near the shore have seen expensive investments swallowed up by the lake in recent decades, only now realising why the indigenous Mayan communities build their houses far from the water’s edge. But why does the water keep rising, and will it ever stop?

Scientific research in the area is very limited, and most of the explanations are only theories at this stage. The explanation of the local Mayan communities is that the water level at Lake Atitlan rises and falls in a cyclical pattern of around 50 years. According to the elders, this has been the case for as long as people have a collective memory.

Some people say that the rising water levels are explained by blockages in the geological fractures that allow water to drain into aquifers. Given that this is the only major outflow from the lake, it seems like a good theory.

Blockages may be created by increased amounts of sediment due to landslides, agriculture and deforestation; or the fractures might have become blocked by the organic material left behind by cyanobacteria blooms that strike when levels of agricultural fertiliser are too high.

There is also evidence that outflows from the lake may have become blocked. In 1976, the area was shaken by a strong earthquake, and water levels dropped significantly. Some say that this is because the earthquake opened new fissures through which the water could leave the lake.

The short answer to the mystery of Lake Atitlan is that no one has yet come up with a definitive explanation for the rising water levels, but certain theories do seem to make more sense than others.