The Opened Waterway of the Geumgang River, Natural Restoration Including the Appearance of Rare Flora and Fauna

Chungnam Province, together with Sejong City, conducted a 10-year investigation from 2011 targeting the entire section of the Geum River Four Major Rivers Project. The results confirmed that many rare flora and fauna inhabit the surveyed area. The photo shows a White-naped Crane, a Class II endangered wild species, found in the Gongju-bo and Sejong-bo sections. Provided by Chungnam Province. Photo by Chungnam Province

[Asia Economy (Hongseong) Reporter Jeong Il-woong] Rare flora and fauna that had disappeared from the Geum River are gradually reappearing. This change is attributed to the opening of weirs (bo) installed as part of the Four Major Rivers Project, with analyses suggesting that opening the weirs has had a positive impact on restoring the natural environment around the Geum River.

According to the "Geum River Water Environment Monitoring Phase 2 (5th Year) Research Project (2011?2020)" data announced on the 21st by Chungnam Province and Sejong City, endangered wild species and natural monuments have been found to inhabit extensively around the Geum River, including areas near Gongju Bo, Sejong Bo, and Baekje Bo.

First, in the sections near Gongju Bo and Sejong Bo, endangered wild species such as the white-naped crane (endangered wild species level II), the otter (level I), the mandarin duck (a natural monument), and the large copper butterfly (an internationally endangered species) were discovered.

Additionally, since last year, the endangered wild species level I white-spotted char has also been found in this section. The white-spotted char is an endemic species of the Korean Peninsula that inhabits only fast-flowing, clean sandy habitats and had not been collected from the main stream of the Geum River since the Four Major Rivers Project. However, after the weirs were opened, the white-spotted char began to reappear in the main stream.

Representative lotic fish species of the Geum River main stream, such as the pale chub and stone loach, also saw their populations decrease after the weirs were installed but have rapidly increased since the sluice gates were fully opened.

Chungnam Province and Sejong City attribute these changes to the opening of the weirs. Opening the weirs has enhanced the health of riparian spaces such as sandbars, gravel beds, mid-channel islands, and wetlands, creating conditions suitable for endangered species and natural monuments to inhabit.

Improved water quality before and after the installation of the weirs supports this claim. For example, Gongju Bo and Sejong Bo were completed in 2011, began partial sluice gate openings in 2017, and have maintained full openings since 2018.

As a result, upstream of Gongju Bo (Gomnaru), the biochemical oxygen demand (BOD) decreased from 3.3 mg/L before the weir opening to 2.9 mg/L after the opening, matching pre-Four Major Rivers Project levels.

Chemical oxygen demand (COD) improved from 7.9 mg/L before opening to 6.7 mg/L after opening (6.1 mg/L before the project), and chlorophyll-a (Chl-a) levels dropped from 48.2 mg/L before opening to 33.6 mg/L after opening (33.0 mg/L before the project).

A Chungnam Province official stated, "Water quality in the Geum River had deteriorated in proportion to the operation period of the weirs following the Four Major Rivers Project. However, since opening the sluice gates of the three weirs?Gongju Bo, Sejong Bo, and Baekje Bo?water quality has gradually improved."

He added, "From next year until 2025, the province plans to expand the third phase of the Geum River water environment monitoring project to include the Geum River Estuary Bank. Through this, we will strive to find the optimal management methods for the Geum River and implement related policies."

This content was produced with the assistance of AI translation services.