Amatitlán lake's catchment area includes Guatemala City. Each year large quantities of untreated sewage, industrial waste and a staggering 500,000 tons of sediment are carried into the lake through the Villalobos River. This has contributed to high levels of pollution of the lake's water, and an accelerated eutrophication and siltation. This has seriously affected the lake's former function as a source of drinking water and irrigation, and reduced its recreational functions
