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UNESCO recognition for Ulsan petroglyphs rekindles preservation, water supply dilemma
A view of the petroglyphs along the Bangucheon Stream in Ulsan / Courtesy of Ulsan Metroplitan Government
By Kim Se-jeong
Following UNESCO’s decision on Saturday to grant World Heritage status to the petroglyphs of Bangudae Terrace in the southeastern city of Ulsan, attention has turned to the long-standing dilemma facing the city: how to preserve the ancient rock art while ensuring a stable supply of clean drinking water for its residents.
The petroglyphs, which stretch along a 3-kilometer section of the Bangucheon Stream, were recognized for their vivid depictions of prehistoric marine life, including whale hunting, on the Korean Peninsula, dating back nearly 7,000 years.
Just 5 kilometers upstream from the UNESCO-designated site sits the Sayeon Dam, the source of Ulsan’s preservation controversy. Built in 1965 to supply water to the city’s newly established industrial complex, the reservoir later became a critical source of drinking water for Ulsan’s 1.1 million residents.
Due to the dam’s design, water overflows naturally without human control. As a result, the petroglyphs begin to submerge when the dam’s water level reaches approximately 53 meters and are completely underwater at 58 meters. Heavy rainfall accelerates this process.
Between 2014 and 2024, the petroglyphs were submerged for around an average of 40 days each year, according to the Ulsan Metropolitan Government.
This prolonged exposure to water has taken a toll. In 2011, scholars and engineers monitoring the site reported damage in 56 areas of the rock art, attributed to repeated submersion since 1972.
The flooding problem repeatedly hampered Ulsan’s bid for UNESCO recognition. In 2015, 2020 and 2021, the World Heritage Committee either rejected the bid or delayed its review, citing unresolved conservation issues.
Over the years, various proposals were floated, including installing a water-blocking wall, constructing eco-friendly embankments, redirecting the stream or building a transparent kinetic dam. All were ultimately scrapped due to concerns over altering the landscape or damaging the petroglyphs and their surrounding environment.
An aerial view of the Sayeon Dam / Courtesy of Ulsan Metropolitan Government
In 2021, the city proposed a solution: the installation of three additional floodgates at the dam’s spillway to keep water levels in the stream low enough to protect the petroglyphs.
However, that plan triggered a fresh controversy — this time over drinking water.
Along with the Nakdong River, the Sayeon reservoir is one of Ulsan’s two primary water sources. Studies estimate that the installation of three floodgates could lead to a daily loss of 49,000 cubic meters of drinking water.
“Ulsan residents oppose losing a big amount of clean drinking water," an Ulsan city official said on condition of anonymity. "Also, people have a belief that the reservoir water is cleaner than the water from the Nakdong River. So opposition is real."
Ulsan Mayor Kim Doo-gyeom acknowledged the competing concerns: “The Bangudaecheon Stream petroglyphs are a source of pride for Ulsan and a valuable heritage site representing prehistoric culture on the Korean Peninsula. But our priority is to secure an alternative water source, since the floodgates would reduce the daily supply of drinking water.”
Construction of the new floodgates has begun and is expected to be completed by 2030.
Unmun Dam in Cheongdo, North Gyeongsang Province, was proposed as an alternative source. However, the plan fell through due to opposition from Daegu’s city government, as the dam also supplies drinking water to Daegu residents.
"We continue to seek ways to supply clean drinking water as well as preserving the World Heritage site," said the anonymous city official.
In academic circles, some are even calling for the eventual dismantling of the Sayeon Dam itself. Moon Myung-dae, a professor emeritus at Dongguk University who first identified the petroglyphs of Bangudae Terrace, argued for full dam removal in his 2023 book on the petroglyphs.
“Once conditions allow for a lowered water level, we must consider dismantling the dam,” he wrote.