Engineering a kingdom
The first capital of Siam, Sukhothai, flourished from the 13th to the 15th century in a region with a difficult climate. Seasonal rains brought floods, while the long dry season created water scarcity. To build a stable city and support its population, Sukhothai's engineers designed and constructed a intricate water management system that still impresses geoarchaeologists today. This hydraulic network was a foundational technology for the kingdom, capturing monsoon runoff and distributing it for agriculture, transportation, and daily use.
The system's core components reveal a sophisticated understanding of hydrology. The city walls, which form a rectangle approximately 2 kilometers by 1.6 kilometers, are enclosed by a series of moats. These moats were for defense but also served as the first line of water control and storage. To feed the city's network, engineers built the Saritphong Dam, also known as Phra Ruang Dam, an earthen embankment built in the 14th century between two mountains to trap runoff. Today, after restoration, the dam is 487 meters long and can hold about 400,000 cubic meters of water. From this and other collection points, a main canal called the Sao-Ho delivered water using a natural slope toward the city.