[Exclusive] "Supplying 650,000 Tons a Day" — Juam Dam, Key Water Source for Semiconductors, Rated Most Vulnerable to Drought

150-Day Water Supply Limit Under Severe Drought
Additional Measures Needed for Extreme Drought Scenarios

Juam Dam, one of the water sources proposed by the government for the Southwest Semiconductor Cluster, was classified as the highest level, 'Grade 5 (Very Highly Vulnerable),' in a drought vulnerability assessment previously conducted by the Ministry of Environment (formerly the Ministry of Climate, Energy, and Environment). While the government plans to reliably supply 650,000 tons of industrial water per day to the semiconductor cluster, some experts point out that additional measures to secure water resources will be required under extreme drought conditions caused by climate change.

Juam Dam. K-water Korea Water Resources Corporation YouTube.

According to the "National Drought Vulnerability Map" released by the Han River Flood Control Office under the Ministry of Environment in June 2023, obtained by The Asia Business Daily on July 1, both Juam Dam and parts of the lower Seomjin River basin were classified as Grade 5, the highest level of drought vulnerability. The report categorized drought vulnerability into five grades based on an integrated assessment of the number of days water supply is possible, exposure, sensitivity, and the ability to secure supplementary water sources. The assessment applied an extreme drought scenario based on the "12-month duration and 30-year frequency" event equivalent to the severe drought of 2015, when precipitation dropped by up to 49% compared to the annual average.

The government plans to supply a total of 650,000 tons of industrial water per day to the Southwest Semiconductor Cluster through Dongbok Dam (300,000 tons), Juam Dam and Jangheung Dam (150,000 tons), Boseonggang Dam (100,000 tons), and Naju Dam (100,000 tons). However, in the Ministry of Environment’s previous assessment, Juam Dam’s drought vulnerability score under extreme drought conditions was found to be 93–121 points, the highest range. A higher drought vulnerability score indicates lower supply stability; for Juam Dam, the period during which it can supply water independently drops to 150 days or less in an extreme drought scenario. Generally, water balance analyses are based on supply stability of over two years. This suggests that in the event of a prolonged drought, the supply stability of the water source itself could be significantly undermined.

The report also estimated that, based on the most severe drought since 1967, the annual water shortage in the Yeongsan River basin would be approximately 170 million cubic meters—the largest among all regions nationwide. Under the same scenario, the water supply periods for Gwangju’s Dong-gu and Buk-gu districts, both of which use Dongbok Dam (included in the semiconductor cluster water supply plan) as their domestic water source, were 542 days and 519 days respectively, falling short of the typical supply stability benchmark of 730 days.

The government has stated that it will prepare additional response measures reflecting the climate crisis in relation to water supply for the semiconductor cluster. An official from the Ministry of Climate said, “Even during the worst droughts recorded in the Yeongsan and Seomjin River basins, we did not reduce the supply of domestic or industrial water, thanks to dam interconnection operations and the use of river water. However, as demand is expected to rise with the creation of the semiconductor industrial complex, we are preparing additional drought response measures, and relevant budgets will be reflected and implemented as part of this plan.”

This content was produced with the assistance of AI translation services.