Nanhua Dam (), originally named Houjie Dam (), is a dam across the

Houku River The Houku River (), also known as the Houjue River or Houjue Creek, is a river of southern Taiwan, and a tributary of the Zengwen River. The river drains an area of in parts of Tainan, Chiayi County, and Kaohsiung City. The Nanhua Dam on the r ...

, a tributary of the

Zengwen River The Zengwen River is the fourth longest river in Taiwan after the Zhuoshui River, Gaoping, and Tamsui, with a total length of about . It flows through Tainan and Chiayi County.It is located in the southwestern part of the island. Names ''Zén ...

in southern

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

. Located at

Nanhua District Nanhua District () is a rural district of about 8,209 residents in Tainan, Taiwan. It has two reservoirs, the larger one being the Nanhua Reservoir. It is the largest district in the city. History After the handover of Taiwan from Japan to t ...

Tainan Tainan (), officially Tainan City, is a special municipality in southern Taiwan facing the Taiwan Strait on its western coast. Tainan is the oldest city on the island and also commonly known as the "Capital City" for its over 200 years of his ...

, the dam was built to provide municipal water to Tainan and

Kaohsiung City Kaohsiung City (Mandarin Chinese: ; Wade–Giles: ''Kao¹-hsiung²;'' Pinyin: ''Gāoxióng'') is a special municipality located in southern Taiwan. It ranges from the coastal urban center to the rural Yushan Range with an area of . Kaohs ...

and is operated by the

Taiwan Water Corporation The Taiwan Water Corporation (TWC; ) is a state-owned water utility providing water supply to most of Taiwan and offshore islands. The company is headquartered in North District, Taichung. History On 16 December 1972, President Chiang Ching-k ...

. Construction work started in December 1988, and impoundment of the reservoir began in July 1993. A conduit to supply water from the reservoir to Kaohsiung was completed in October 1993 and the entire project was operational in March 1994. The curved earthfill dam is high and long, impounding a reservoir with a capacity of and an active or useful capacity of . The reservoir naturally receives water from a catchment of , which is not enough to fill it alone. Most of the water is actually diverted through a tunnel from the

Qishan River The Qishan River () or Nanzixian River () is a tributary of the Gaoping River in Taiwan. It flows through Chiayi County, Kaohsiung City, and Pingtung County for 117 km. Bridges * Jiaxian Bridge See also *List of rivers in Taiwan This ...

to the east, adding to the drainage area. The tunnel provides an average of 160.6 million m³ (130,200 acre feet) of water to the reservoir each year. Because of its location in a mountainous region, Nanhua is prone to heavy sediment accumulation. A small upstream diversion weir was built to send water laden with silt through a bypass tunnel and allow the remaining clear water to enter the reservoir. However, large amounts of silt are still carried into the reservoir during flooding events. In 2009 alone, flooding caused by

Typhoon Morakot Typhoon Morakot, known in the Philippines as Typhoon Kiko, was the deadliest typhoon to impact Taiwan in recorded history. The eighth named storm and fourth typhoon of the 2009 Pacific typhoon season, Morakot wrought catastrophic damage in Taiwan ...

dumped 17 million m³ (14,000 acre feet) of silt into the reservoir. In February 2010, the Taiwan Water Corporation began the first stage of a two-year sediment removal project at Nanhua.

References

1994 establishments in Taiwan Dams completed in 1994 Dams in Tainan Earth-filled dams {{taiwan-dam-stub