The Ministry of Climate, Energy and Environment said on the 30th it would secure the 650,000 tons of water needed per day for the Honam semiconductor industrial complex by raising the Dongbok Dam and diverting surplus water from several dams. The explanation came after Samsung Electronics and SK hynix reported to the Blue House the previous day that they would invest 800 trillion won in Honam to build four semiconductor fabs, prompting criticism that the government had not properly explained how it would secure water.
Earlier, the government estimated the water needed for the Honam semiconductor complex at 650,000 tons per day. It expected 150,000 to 200,000 tons per fab. The climate ministry said it would secure the 650,000 tons from ▲Dongbok Dam (300,000 tons) ▲Jangheung Dam (100,000 tons) ▲Boseong River Dam (100,000 tons) ▲Naju Dam (100,000 tons) ▲Juam Dam (50,000 tons).
Dongbok Dam, the largest single source of the planned supply, is a major drinking water source that provides 270,000 tons a day to the Gwangju area. The climate ministry said it would divert 50,000 tons of Dongbok's 88,000-ton surplus to the Honam semiconductor complex and, by raising the dam, secure an additional 250,000 tons. Among the seven dams in the Honam basin, Dongbok is said to have the lowest water resources utilization—actual use relative to supply—in the 40% range. The national average dam water resources utilization is in the 80% range. This means a large volume could be secured by raising Dongbok Dam. The ministry was said to plan to break ground on the dam-raising within five years.
It also said it would use 100,000 tons out of Jangheung Dam's 110,000-ton surplus and allocate 50,000 tons out of 70,000 tons of Juam Dam's unutilized municipal and industrial water to the Honam complex. In addition, it plans to convert 100,000 tons of Boseong River Dam hydropower water to industrial water. Boseong River Dam is a hydropower dam upstream of Juam Dam. Of the water discharged to the sea for power generation, 100,000 tons a day would be sent toward Juam Dam and supplied to the semiconductor complex. In this case, there would be generation losses, which the ministry believes could be offset with water fees collected from corporations.
In addition, Naju Dam would secure industrial water by saving on existing agricultural water supply. Agricultural water would be replaced with Yeongsan River stream water.
However, there are concerns that this water supply plan could worsen shortages if Honam faces a drought as severe as in 2022–2023. In that period, the Gwangju–South Jeolla region saw more than 281 days of drought from 2022 to 2023. The Juam Dam storage rate fell into the 20% range, and the government implemented emergency measures such as sending Boseong River Dam hydropower water to Juam Dam.
In response, the government announced in 2023, through the "Yeongsan River–Seomjin River basin mid- to long-term drought countermeasures," that it would gradually secure an additional 610,000 tons per day of water resources. This plan does not reflect the construction of Honam semiconductor fabs. A climate ministry official said, "We will supplement the mid- to long-term drought countermeasures to reflect semiconductor plant construction."