Zengwen Reservoir is the largest reservoir in Taiwan by original design capacity, located in the mountains of Nanxi District, Tainan. Completed in 1973 with a storage capacity of about 708 million cubic meters and a dam roughly 133 meters high, it impounds the waters of the Zengwen River to supply irrigation and daily water use for Tainan and Chiayi.
Zengwen Reservoir has a catchment area of 481 square kilometers and an earth-and-rockfill dam approximately 133 meters high. When completed in October 1973, its total storage capacity was about 708 million cubic meters, making it Taiwan's largest reservoir at the time. After decades of sedimentation, worsened by Typhoon Morakot in 2009, its measured total capacity had fallen to roughly 506 million cubic meters by 2023; the Water Resources Agency continues desilting projects to address this.
What to See at Zengwen Reservoir
Zengwen Reservoir's catchment area covers 481 square kilometers, encompassing the mid-to-upper mountain reaches of the Zengwen River. When it was completed in 1973, it was Taiwan's largest reservoir, supplying agricultural irrigation, industrial water use, and household drinking water for both Tainan and Chiayi. The dam stands approximately 133 meters high; the concrete structure is in good condition and represents an important achievement in Taiwan's water engineering history.
The reservoir is surrounded by mountains, the lake surface is expansive, and the scenery varies markedly at different water levels. A viewing platform on the main dam crest overlooks the dam structure and the reservoir surface. A visitor center below the dam provides basic information about the reservoir. The surrounding mountain forest coverage is substantial, making it one of the rare mountain-forest landscapes in Tainan — and a local leisure and recreation destination.
How to Make the Most of Your Visit
Practical Information
Getting There & Timing
- Located in the mountains of Nanxi District, about 60 km from central Tainan; driving is recommended — the mountain roads are winding, so drive carefully.
- During typhoons or heavy rain, the reservoir management authority may impose access restrictions; check access conditions on the Southern Region Water Resources Office or reservoir website before departure.
- Spring and early summer can be misty; visibility is best on stable winter days, which are a good time to plan a reservoir day trip.
Nearby Connections
- The Meishan hiking trails in Nanxi District are about a 20-minute drive from Zengwen Reservoir; the plum blossom season (January to February) draws many visitors.
- Wushantou Reservoir is about a 40-minute drive from Zengwen and can be included in an extended route covering Tainan's reservoir landscapes.
Source: compiled from contextual facts; for reservoir access conditions, please consult official announcements from the Southern Region Water Resources Office. Photos pending replacement with Dio's actual shots.
Frequently Asked Questions
Is Zengwen Reservoir Taiwan's largest reservoir?
Yes — at its 1973 completion, Zengwen Reservoir's storage capacity was about 708 million cubic meters, the largest in Taiwan, though sedimentation has since reduced its actual capacity.
What areas does Zengwen Reservoir supply?
It mainly supplies agricultural irrigation, industrial use, and drinking water for the Tainan and Chiayi areas.
How tall is the Zengwen Reservoir dam?
The dam is an earth-and-rockfill structure roughly 133 meters high, among Taiwan's tallest dams.
Does Zengwen Reservoir still hold 700 million cubic meters of water today?
No — due to sedimentation and typhoon damage, its measured total capacity had fallen to about 506 million cubic meters by 2023.
Sources
- 水利署全球資訊網-主要水庫簡介-曾文水庫 — 官方蓄水容量、集水區面積、竣工年份
- 曾文水庫 - 維基百科 — 完工時原始容量、壩高、淤積說明