Chilseo, 'interest' stage in Mulgeum and Mary branch... Environmental group urges immediate opening of dam
(Changwon = Yonhap News) Reporter Park Young-min = The number of harmful blue-green algae cells has rapidly increased at the water supply point downstream of the Nakdong River, and temperatures this summer are forecast to be higher than average, raising concerns about the spread of green algae.
According to the Nakdong River Basin Environmental Office on the 11th, the number of harmful blue-green algae cells at the Chilseo branch of the Nakdong River between Haman-gun and Changnyeong-gun in Gyeongsangnam-do increased from 4,877 per ml on the 1st to 7,280 on the 8th.
The number of Mulgeum and Mary branches between Yangsan-si and Gimhae-si increased 3.5 times from 2,418 to 8,458 per ml during the same period.
The algae warning system in the water supply area is issued when the number of harmful blue-green algae cells, which cause green algae, exceeds 1,000 per ml for two consecutive times, 'Concern', when the number is more than 10,000, 'Warning', and when it is more than 1 million, 'Outbreak' level is issued.
As of 6 p.m. on the 8th, the Nakdong River Office issued the first bird warning alert level of the year to Chilseo, Mulgeum, and Mary branches.
According to the water environment information system's algae forecast information, the number of harmful blue-green algae cells at the two locations was predicted to have already exceeded the alert level standard of more than 10,000 per ml on this day.
Last year, harmful blue-green algae increased rapidly in the lower reaches of the Nakdong River after June.
At the Chilseo branch, 2,124 harmful blue-green algae per ml were observed on May 26 and 2,762 per ml on June 2, and a concern level was issued on June 5.
Afterwards, the number rapidly increased to 32,847 per ml on July 7 and 33,714 on July 14, leading to the upgrade to the alert level on July 17.
This year, the Korea Meteorological Administration predicts that temperatures from June to August will be higher than average, raising concerns about the spread of green algae due to rising water temperatures.
Harmful blue-green algae tend to proliferate in the summer when water temperature rises and solar radiation increases.
Accordingly, environmental groups argue that the opening of the Nakdong River Weir must be expedited.
Lim Hee-ja, co-representative of the Machangjin Environmental Movement Federation, said, “The government said it would take preemptive action to manage green algae through a seasonal management system, but the opening of the weir has been postponed since the green algae began to spread,” and argued, “If it reaches the level of the algae warning outbreak in 2018, opening the weir will be of no use.”
He added, “Temperatures are expected to be high this year, so green algae growth may become more severe. If this situation continues, it will be difficult to easily resolve the problem unless typhoon-level rainfall occurs.”
The Ministry of Climate, Energy and Environment plans to reduce green algae by sequentially opening eight weirs on the Nakdong River in accordance with the period when green algae spreads in earnest.
However, considering the use of agricultural water during the farming season, it is not easy to advance the opening of the dam.
Nakdong River Authority is holding a 'Green Algae Seasonal Management System Nakdong River Basin Promotion Team Meeting' with Gyeongnam Province and Korea Water Resources Corporation, and is responding to green algae outbreaks by inspecting algae barriers and water purification facilities.
An official from the Nakdong River Office said, “We have been conducting inspections such as open compost management to reduce the inflow of pollutants,” and added, “We will do our best to respond to green algae outbreaks and provide safe water through a public-private collaboration system.”
