TEHRAN - Recent heavy rainfall in Fars province led to the destruction of parts of historical houses in Shiraz, the provincial capital which is situated 70 km southward from Persepolis, which was once a ceremonial capital of the Persian Achaemenid Empire (c. 550 – 330 BC).

However, Persepolis successfully drained a significant volume of water thanks to its underground channels, originally constructed during the Achaemenid era and known as the Achaemenid water channels, ILNA reported on Sunday.

Videos circulated on social media showing water overflowing from Persepolis’ staircases, raising concerns about severe flooding similar to past years before the discovery and cleaning of these ancient drains. However, it has now been confirmed that these underground channels, designed over 2,500 years ago to manage surface water and potential floods, efficiently directed large amounts of rainwater away from the site, the report explained.

100 millimeters of rainwater drained from Achaemenid palaces

Alireza Askari Chaverdi, the director of the Persepolis World Heritage Site, told ILNA that crisis management is a key part of the site’s management plan. A specialized task force was formed to implement the crisis management plan, which was executed during the recent heavy rains.

The archaeologist and site director stated that restoration and monitoring teams collaborated with archaeologists, technical personnel, and the Persepolis security unit to address surface water challenges over two days of rainfall, successfully directing 100 millimeters of rainwater out of the Persepolis terrace.

“Preventive conservation measures were conducted a week before the rainfall, covering the entire 12-hectare complex and the 7-hectare Rahmat Mountain fortifications. Additionally, the 2-kilometer-long underground water channels of Persepolis were thoroughly cleaned in preparation for the expected rain,” the archaeologist explained.

During the rainfall, the crisis management team remained on-site to monitor various sections and ensure the water was directed through ancient drains out of Persepolis, the archaeologist underlined.

Readiness to control water accumulation

Shahram Rahbar, head of the Persepolis restoration team, highlighted the site’s extensive 125,000-square-meter area. “When including the southern residential district and the tombs of Artaxerxes II and III in the eastern highlands, the total area exceeds 250,000 square meters,” Rahbar added.

He pointed out that managing [potential threats of] rainfall is a major challenge, and the technical team is responsible for protecting Persepolis’ invaluable structures. In preparation for the storm, the conservation and restoration teams, along with civil and maintenance teams, were ready to handle potential flooding and prevent damage to active restoration workshops.

Despite three consecutive days of predicted rainfall, coordinated efforts ensured that visitor paths remained open and active restoration projects were protected. Close coordination between the security unit and conservation experts ensured overnight monitoring of vulnerable sections, with continuous communication over two nights to manage potential flooding risks, the expert explained.

Rahbar noted that, despite exhaustion from two days of continuous work under heavy rain, a coordinated effort ensured effective water management. By Friday, when the rainfall intensified, field teams systematically monitored the site and executed emergency measures to protect the monuments.

According to Rahbar, the key achievement was preventing damage to stone artifacts and active stone restoration sites. “Thanks to collaborative efforts among conservation, maintenance, and security teams, the storm did not significantly impact visitor accessibility or preservation activities.”

Discovery of Achaemenid drains ends decades of flooding

Parts of Persepolis’ drainage system were first identified during excavations by the University of Chicago’s Oriental Institute. However, these channels remained hidden until the 2000s when archaeologists gradually uncovered and cleaned them, leading to a major breakthrough in the 2010s. That restorations enabled the complete drainage of surface water through the site’s original ancient system.

The Achaemenid rulers designed these water channels to control rainwater flow from the palaces to areas outside Persepolis. Over time, these channels became filled with soil, leading to repeated flooding that caused damage to the site. However, extensive archaeological excavations eventually restored their function, permanently solving Persepolis’ flooding issues from the 2010s onward.

Glimpses of Persepolis

Also known as Takht-e Jamshid, Persepolis ranks among the archaeological sites, which have no equivalent, considering its unique architecture, urban planning, construction technology, and art.

Majestic approaches, monumental stairways, throne and reception rooms, and dependencies have made the vast ensemble one of the world’s greatest archaeological sites.

Construction of its immense terrace was begun about 518 BC by Darius the Great, the Achaemenid Empire’s king. On this terrace, successive kings erected a series of architecturally stunning palatial buildings, among them the massive Apadana palace and the Throne Hall (“Hundred-Column Hall”).

The terrace is a grandiose architectural creation, with its double flight of access stairs, walls covered by sculpted friezes at various levels, monumental gateways, gigantic sculpted winged bulls, and remains of large halls.

By carefully engineering lighter roofs and using wooden lintels, the Achaemenid architects were able to use a minimal number of astonishingly slender columns to support open-area roofs. Columns were topped with elaborate capitals; typical was the double-bull capital where, resting on double volutes, the forequarters of two kneeling bulls, placed back-to-back, extend their coupled necks and their twin heads directly under the intersections of the beams of the ceiling.

Narratives say that Persepolis was burnt by Alexander the Great in 330 BC apparently as revenge against the Persians because it seems the Persian King Xerxes had burnt the Greek City of Athens around 150 years earlier.

AM