- March 15, 2020 3:51 AM
- October 17, 2020 9:27 AM
- March 12, 2023 8:42 AM
SIEM REAP – Water has an interesting and pivotal role to play in the survival of the Angkor Archaeological Park. Located right in the middle between two important sources of water, Mount Kulen and the Tonle Sap Lake, the city of Angkor relied heavily on a healthy amount of water for agricultural and engineering aspects, as well as for spiritual purposes.
Speaking at a forum on the Khmer Art from the Angkor era, in Siem Reap province, Hang Peou, the director general of the APSARA National Authority, who is also a hydrologist, explains the essence of water and how it shapes the survival of this ancient hydraulic city.
Ky Soklim: How many ancient water reservoirs are there within the Angkor Archaeological Park?
Hang Peou: We can clearly see four ancient water reservoirs, however, there are actually five of them: The Eastern, Western, Northern and Lolei reservoirs, and the Southeastern reservoir which received water from the Eastern one. It was right on the axis of Angkor Wat temple and had a capacity of around 20 million cubic meters of water. When combined with the moats surrounding the temple, all of them could hold at least 120 million cubic meters of water.
Ky Soklim: So, if the amount of water exceeds the infrastructure capacity, will the park be flooded?
Hang Peou: Actually, if we respect the functionality of this old system, Angkor Park cannot be flooded. The system was created so that the use of water can be as efficient as possible until the last drop. The moats and the reservoirs themselves hold onto the excessive water and distribute the water back when needed. That being said, there is one exception. The system cannot function on its own and needs manpower with knowledge and know-how to operate it. This was the problem during the 12th and 13th centuries in the region of Angkor Thom. Although it was not recorded in history, I, as an expert in hydrology, know that there was an issue with the water management from above [north].
Ky Soklim: As I remember, water alone does not act as a lone supporter of the temples. Somehow, sand also plays a crucial job in maintaining balance. Could you please explain more about the relationship between these two elements?
Hang Peou: Based on the research done by the French School of the Far East (EFEO), whenever the experts excavate the soil here, they always find layers of sand or a mixture of sand and laterite stones. As a hydrologist, I am due to question myself. Do these layers have anything to do with water? Not all kinds of sand can be useful to sustain the temples’ foundations. Very fine sand can slip easily making it impractical. So, a carefully calibrated mixture of sand and other earthy materials was combined within a dug-up space so that the material property can support the weight of the temples when they are soaked with enough water. That is the reason why the ancestors built moats around the temples. They act as a mechanism to hold water and protect the temple from flooding as well as hydrate the sand to support the temple’s foundations.
Looking at Lolei, you can see that the reservoir was dug at the northern side and, because of the flow, the water is transported down south to help hydrate the soil. The size of the temple and the moat has to be very proportional. A small temple will have a shallower and smaller moat. This is one of the reasons why smaller temples fall down easily since the supply of water becomes short and the flow of water changes over time. It is also crucial to understand that temples are made of piled-up stones. When unstable, stones can fall down one by one.
However, not all temples need a moat around them. A few exceptions, being the mountain temples of Bakheng and Preah Vihear, were built directly on solid rocks that guaranteed the structure was stable.
The presence of a moat and a temple is often associated with the ideas of the ocean and a mythical mountain. But, in reality, this concept was not always followed. For instance, the ponds along the way toward the mountain temple of Preah Vihear were made only to store water for everyday uses.
Another convincing example would be the ancient bridge called Spean Toab. During wartime, tanks and overloaded trucks used to traverse that bridge. Yet, it still stands strong today. This is because the soil underneath that bridge is always hydrated. If the Angkor Park was hydrated all along, many temples would still stand strong unless the stones themselves erode due to other different factors.
Ky Soklim: You said the majority of the water in the Angkor Park derives from Mount Kulen. On top of this crucial mountain, a vast ancient sculpture called the One Thousand Lingas was sculpted. What is the meaning of such carvings?
Hang Peou: People consider this water as amrita (elixir of immortality). However, from a scientific perspective, one must acknowledge that it is no easy task to carve stones under the water over a distance of several kilometers. So why would our ancestors do this? What kind of message were they trying to preserve and send to the younger generation? Their message is very simple. They would like us to please respect the water source at Mount Kulen since it is the lifeblood of the Angkor region. The message is hidden behind spiritual practices since it is easier to pass down between generations. Another aspect is that the shape of the sculpture helps create more turbulences that add more oxygen to the water. Until today, that water is blessed: The coronation of the King requires having water from Mount Kulen. When one is able to take care of that source on Mount Kulen, that water will support the stability of temples through the system of moats and reservoirs.
Ky Soklim: Do all waterways in Angkor have their origin in Mount Kulen?
Hang Peou: The main water supplies originate from Mount Kulen and other locations on its foot. One example would be the Rolous area where Bakong temple is located. This area is connected to the Rolous Stream which also comes from the foot of the mountain. However, when the water supply became short, our ancestors built a canal to connect it to the Siem Reap Stream, which ran from Pouk Stream instead.
Interviewed in Khmer for ThmeyThmey News, this article was translated by Ky Chamna for Cambodianess.