A bigger water basin needed to cope with weather extremities

The recent raining pattern around the Korean Peninsula implies a warming climate has been shortening rainy days while increasing the severity of rainfall. When it rains, it pours to catalyze flooding. When it does not, a sizzling heat wave causes...

The recent raining pattern around the Korean Peninsula implies a warming climate has been shortening rainy days while increasing the severity of rainfall. When it rains, it pours to catalyze flooding. When it does not, a sizzling heat wave causes blistering drought. This summer’s monsoon season has been no different, with rainfall frequently exceeding 100 millimeters (3.93 inches) per hour.

The Environment Ministry earlier this week announced 14 candidate locations for new dams to cope with the changes in the precipitation pattern. The Bohyeonsan dam completed in 2011 was the last multipurpose dam built in the country. The government in 2018 announced it wouldn’t be adding dams. Authorities, however, cannot afford to stick to its past stance, given the volatile changes in precipitation. A bigger water basin is needed to accommodate the heavier downpours and moderate water supplies during dry spells. The Environment Ministry argued that if there had been a dam in Yecheon, North Gyeongsang, the drowning of eight in a parking lot due to a sudden flood in Pohang could have been avoided, when Typhoon Hinnamnor slammed the southern port city in 2022. An additional dam in Seomjingang can help alleviate the seasonal spring drought that affects farmers in South Jeolla.

Sufficient water supplies are also imperative to run advanced industrial complexes, including new chipmaking facilities. Dam construction demands strenuous preparatory procedures. In the past, authorities pushed ahead with dam constructions just after compensating for the affected lands. Such a top-down approach in the name of a national project cannot work these days. Yanggu in Gangwon is already protesting a new dam project, as the region is close to the Soyanggang dam. A dam project in Jicheon, Chungyang, in South Chungcheong was canceled due to strong protests from residents in 2012. In order to avoid an exhausting conflict, authorities must prepare well to convince residents and compensate for any losses.

The environmental risks also must be thoroughly investigated. The Yongju dam in North Gyeongsang gained a permit for operation only last year after stalling for seven years upon completion in 2016. The water reservoir was contaminated before damming because pollutants had not been thoroughly studied before the construction. The ministry argues it had made sufficient investigations before choosing the candidates for new dams. Still, it must be meticulous in its feasibility study and blueprinting process to spare no risks.

The dam capacity also requires deeper study. The new candidates will be designed to accommodate precipitation of 80 to 200 millimeters. Given the latest pattern, that amount of rainfall can bucket down within a few hours. When water levels reach beyond the dam's capacity, the gates must open, causing danger to the downstream areas. Last year, the waters walled by Goesan dam overflowed due to heavy storms. Dams aimed to prevent flood must not become the source of a greater danger.