Straightening of the Keelung River had a strong impact on Taipei City

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When you look today at the Keelung River in Taipei, everything seems normal and nothing unusual is to see. But those who live longer in Taipei might remember that the river had a very different course.

I do not live for very long in Taipei and for me the Keelung River always appeared normal. It wasn’t until a few years ago, when I studied historical maps and aerial images of Taipei that I noticed the different course of the Keelung River. After some more reading I learned about two massive changes in the river course during the 1960s and 1990s. These changes transformed the Taipei districts of Shilin (士林), Dazhi (大直) and Neihu (內湖) into the districts we know today. Actually, most parts of Dazhi and Neihu could be only created due to the river changes.

First phase of river straightening

The first river straightening was done from 5. November 1964 to 19. July 1965. In nine months of construction the river section in Shilin was moved about 500 meter to the west. Originally the river turned at the Grand Hotel towards north to Jiantan. Near the Shilin night market the river turned towards the northwest. And near the todays Taipei Children’s Amusement Park the river turned west and entered the still existing river bed.

The abandoned meander was kept as an oxbow lake until the 1980s, but then it was filled and new buildings constructed. Today the old river course is still recognizable in the layout of the streets. Shishang Road (士商路) and the parallel Jihe Road (基河路) follow the old river banks. Interestingly, the Chinese name of Jihe Road is 基河路 and derives from Jilong He (基隆河), which is the Chinese name of the Keelung River.

Second phase of river straightening

The second phase with the biggest impact on the city was the straightening of the sections in Dazhi and Neihu from 11. November 1991 until 10. November 1993. Two large meanders were cut off and the river was shortened by 6 km. In contrast to the first straightening in the 1960s, the abandoned meanders were immediately filled and developed, creating large parts of Dazhi and Neihu.

River straightening in Dazhi

The aerial images show the straightening of the Keelung River in the Dazhi section. In 1991 the river is still in its original bed. At that time the river made a large meander towards the north almost to the foot of the Jiannan Mountain (劍南山). The image from 1994 shows already the new river bed with the partly filled and developed old meander. In the image from 2002 the old meander is hardly visible. Only the Mingshui Road (明水路) and Tiding Boulevard follow the old river banks (堤頂大道).

River straightening in Neihu

During the river straightening in Neihu two meanders were cut off. In 1992 the large meander, which stretched 1.5 km in to eastern direction, was cut off. The smaller meander located in Nangang (南港) north of Kunyang  (昆陽) was cut off in 1993. Similar as in Dazhi, the aerial images from 1993 and 2002 show very clearly that the old meanders were immediately filled and developed.

The old meanders are hardly visible in today’s street network in Neihu. Only the Xingshan Road (行善路) partly follows the big meander. The small meander is not visible anymore.

Keelung River straightening to mitigate flood risk

In the past Taipei was plagued by frequent floods from the rivers in the basin. In 1963 the low-lying areas of Taipei and New-Taipei were flooded due to typhoon Gloria. For almost two days the water stood two meters high. This flood caused huge damage to agricultural areas, which were located in the flood plains.

Until then the government used traditional methods for flood protection, such as dikes or washlands, which are areas that can be deliberately flooded. But another large flood in Taipei caused by typhoon Nelson in 1985 led to the decision for radical flood prevention measures.

It was expected that straightening of the Keelung River in Dazhi, Neihu and Nangang, would allow the flood water to flow faster and hence reduce the flood risk in these areas. A positive side effect was that the newly reclaimed areas could be used for city development. The tight meanders of the Keelung River were more or less a disadvantage for city development.

However, river straightening was controversial. Many people had to give up their houses and were relocated. But there is also a strong impact on river ecology and increased risk of floods in the not straightened downstream sections of the river. Because the now fast flowing water will get dammed up somewhere downstream. In Taipei this might be not such a big issue, because the Keelung River drains into the much larger Tamsui River. And the Tamsui River brings all the water quickly into the Taiwan Strait.

To further improve flood prevention in Taipei, the Yuanshanzi Flood Channel (員山子分洪道) was built between 2003 and 2005. The channel, or actually a tunnel, is located in the upstream sections of the Keelung River in Ruifang and connects the river directly with the ocean. If there is too much water coming from the mountain areas, it can be diverted directly into the ocean without having to flow through Taipei. Since its opening the Yuanshanzi Flood Channel has proven to be highly effective for flood prevention and has protected Taipei many times from floods.

Further reading

For those who want to learn more about the history of Taipei and the rivers, I recommend these articles as a starting point:

“Taiwan in Time: Cutting out the river bends”

“Taipei from the River”

And for those who like historical maps and want to explore Taipei’s past:

Historic maps and aerial images of Taipei from the Japanese era until today

Discover old Taipei – Taipei Historical Maps App

Titel image by Janet Chen from Pixabay