The four rivers project of conservative former President Lee Myung-bak faces yet another reevaluation. At issue here is whether it contributed to the flooding during the recent deadly downpour. The Lee administration refurbished the Geum River, Yeongsan River, Nakdong River and Han River, and built weirs along them in a bid to prevent flooding and droughts.

The latest floods took place as heavy rain washed away the levee of the Seomjin River in Namwon City, North Jeolla Province on Aug. 8, and also broke that of Nakdong River in Changnyeong-gun, South Gyeongsang Province, on Aug. 9.

Rep. Chung Jin-suk of the main opposition United Future Party said on Facebook on Aug. 9: “I hear many people say, ‘The downpour proved the four rivers project was effective in preventing floods. Where would we be now without it?’”

Experts who participated in the project concurred, noting that the project lowered the water level of the four rivers by dredging their beds. They argued if the Seomjin River had been dredged like the four rivers, the Namwon dike would not have broken.

Rep. Youn Kun-young of the ruling Democratic Party of Korea rebutted this, posting on Facebook that “many studies demonstrated the harmful effects of the four river project.”

Experts who have opposed the project argued the break of a Nakdong River levee was caused by the weir in Changnyeong that slowed the river flow, raising the water level and pressure.

Finally, President Moon Jae-in instructed a probe into the flood control effectiveness of the weirs at the four rivers.

His instruction does not look constructive. Reevaluation of the project will likely cause strife along partisan lines. It is hard to understand why he rekindled the age-old controversy over the project when restoration from flood damage is urgent.

Evaluations of the project varied depending on which government assessed it. In 2014, a committee under President Park Geun-hye’s government found the project effective in preventing floods in 93.7 percent of the mainstream areas of the four rivers. In 2018, the Board of Audit and Inspection under Moon’s administration concluded that its value in flood prevention was “zero won.”

Generally, residents near the four rivers are positive about the project, arguing it has reduced flood risks, while environmental groups have called for the immediate dismantlement of the weirs.

It would be desirable for a team of neutral experts to assess the project impartially from a purely scientific standpoint.

But it is not easy to secure such neutrality, and the general public will find it difficult to accept evaluation results as unbiased as rival parties continue to argue about them.

Though experts participated in previous probes, too, they produced split results.

No matter what conclusion the new team of experts reaches, politically biased interpretations are inevitable.

The argument that both supporting and opposing views of the weirs exist because they actually have positive and negative functions stands to reason.

But the government is focused on whether the project is good or evil, and whether to tear down the weirs.

Many people have suffered damage due to the unusually long downpour.

Generally, most floods occur at weak tributaries of a river, not on its course. The four-river project ended in 2011 without refurbishing tributaries and small streams properly amid opposition from environmental groups. If improving the distributary channels of rivers can reduce flooding or drought risks sharply, the government must renovate them quickly.

It is hasty to seek the dismantlement of weirs on the four rivers. Heads of local governments in the area surrounding Geum River oppose the removal of the weirs, though they belong to the ruling party. That’s because they have a positive opinion of the weirs.

The top priority for the government right now should be to help the nation recover from flood damage.

The four-river project must be evaluated free from external influence. Otherwise, it will only raise suspicions that the current administration may intend to shift blame for its failure in water control onto past governments.