Kah Hoe: Angkor ~~ Barays

In the Angkor region the first great barays were Indratataka at Hariharalaya, built by Indravarman I in the late 9th century, and the East Baray at Angkor, also begun by Indravarman but completed by his son and successor, Yashovarman I. The East Baray is a monumental artificial lake measuring 1.8km by 7.5km, which is 1.1 miles wide and 4.7 miles long. As with all the great barays, it was built by excavating and piling up an enormous earthen retaining wall, about 4m-5m (14') tall, around the perimeter, so that the water was held above ground behind what is, essentially, a giant dyke.

Now the east Baray become the bundled rice fields.

The East Baray was fed by the Siem Reap river, and would have held 37.2 million cubic meters of water at a depth of 3m (10'). (A figure of 55 million cubic meters of water is also quoted; the larger figure assumes an average water depth of 4.5m). The amazing scale of such a construction, and the amount of labor (about 10,000 man-years) necessary to dig and pile up the reservoir walls, can hardly be put into adequate words. Most likely the water was used for irrigation (this has been questioned, but recent surveying and satellite imagery seem to confirm it). Waterworks on this scale must also have had stunning religious and political implications.

Every year April to June are dry season, in the west baray able to see a lot of pile yellow sand.

The major problem with the baray system was siltation - the gradual influx of sand, carried by the river, into the reservoir. The East Baray was completed around 890. During the next century, as it gradually became filled up with sand, it was periodically renovated by raising its banks, and new, smaller, barays were constructed to supplement the water supply (Srah Srang, east of Banteay Kidei, mid-10th century). The enormous West Baray was completed in the mid-11th century, followed later by diversion of the Siem Reap river around the East Baray and into excavated canals. The last great baray at Angkor was the Jayatataka, built by Jayavarman VII (1181-1218). By the mid-13th century, the baray system had exhausted itself, as the process of siltation outpaced the ability of the Khmer to raise the height of the reservoir walls.

Subsequently, stone bridges were used as dams. These could be blocked up to create a reservoir behind the dam, or unblocked to feed water through a system of canals. For example, a dam was built between the south bank of the Jayatataka and the north bank of the East Baray, to back up the flow of the Siem Reap between the two barays. Unfortunately, these dams had a design problem. Their earthen dykes could become weakened due to erosion, and subsequently break. This happened at least twice: in the 13th century at the Jayatataka, causing a major flood to the east part of Angkor, and in the 16th century at Spean Thma (damming the river just west of Ta Keo.) The later flood was so extensive that it re channeled the Siem Reap river into its present course.

In the west baray southern dike become a popular place for swimming and boat rides by local residents. It has occasionally served as a landing site for seaplanes.