The Khmer Empire depended primarily on rice agriculture. However, they also grew vegetables like pepper and had orchards where they grew betel nut and coconut trees. Khmer people also used the Tonle Sap for fishing. In fact, two hundred species of fish lived in the lake. People even built floating houses on the lake to fish from.

The Tonle Sap also provided a source of water for drinking, irrigation, and transportation. The Khmer people were experts at water engineering. They built giant man-made lakes called barays to hold water for convenient use. They also built extensive (complicated) canal systems which provided water for crops and which were also used for transportation.