Officials of the Ministry of Homeland and Maritime Affairs in charge of the Four Rivers Development Project, the local authorities along the rivers and millions of residents are anxiously watching the water levels rising in this rainy spell. They all fear possible damage to the embankments, dikes and bridges built over the past couple years under President Lee Myung-bak’s signature project.

The year’s first typhoon, Meari, did not directly hit the peninsula but brought downpours of more than 300 millimeters to the central areas of South Korea. The “Bridge of Defense” in Waegwan, North Gyeongsang Province, where South and North Korean forces fought fiercely for control of Nakdong River during the Korea War (1950-53), collapsed due to the floods. Piers of the bridge gave way, causing a 100-meter span to sink into the water on Saturday. Environmental activists claimed that a massive dredging of the riverbed as part of the four-river project made the bridge vulnerable to flooding.

Earlier rains have already destroyed dikes in Yeoju, Gyeonggi Province, Sangju, North Gyeongsang Province and other newly built facilities along the Han, Nakdong, Geum and Yeongsan Rivers. The Homeland Ministry’s engineers have built makeshift levees to protect dams under construction and the ministry said they proved useful in minimizing damage from the rains accompanying Meari.

But it was just the beginning of a long rainy season. The nation could see up to 10 more typhoons bringing heavy rains by this autumn. The four-river project to make the main waterways deeper, broader and more beautiful is about 70 percent complete. Nobody knows how much damage recurring floods will inflict on the new facilities.

The vulnerability of the river work comes from the fact that all sections of the project started construction almost at the same time and foundations are therefore not strong enough to sustain against floods. But government authorities have asserted that heavy rains will prove them right, as the river project ― still incomplete ― is intended to reduce damage from floods. At stake are huge state assets as well as public confidence in the government. The authorities and contractors should take no chances and render all efforts to prevent major disasters.