[3] The dam stores water for irrigation of the Chianan Plain, Taiwan's most productive agricultural region, and provides flood control along the Zengwen River which flows through Tainan City.

Also built was the Tungkou Weir on the Zengwen River, a 220.8-metre (724 ft) long structure designed to divert the water into the Guantian tunnel.

[9] In 1939, Japanese engineer Hatta Yoichi proposed the construction of a concrete gravity dam at a place called Lioutengtan, to control the floods and block silt, but these plans were dropped due to the intervention of World War II.

A rolled-earth embankment cofferdam was constructed to divert the Zengwen River and protect the dam site from flooding, up to an elevation of 165 metres (541 ft).

Due to a large volume of unstable sandstone, clay and shale that comprised the slope where the spillway was to be built, about 6,040,000 cubic metres (213,000,000 cu ft) of material had to be removed before concrete placement could begin.

The entire project consisting of dam, spillway, and power station was formally completed and dedicated on October 31, 1973, exactly six years after the beginning of construction.

Because dam releases are determined by irrigation and domestic water supply needs, power generation is secondary (incidental) and does not always correspond to demand on the grid.

If the Central Weather Bureau issues a typhoon warning, and the reservoir level is higher than the flood-control pool, the gates may be opened to drain the extra water ahead of time, to reduce the risk of a sudden uncontrolled overflow that might endanger lives and property downstream.

It also allows for boats to access remote villages in Dapu township, which prior to the dam's construction could only be reached by winding mountain roads.

[16] The Zengwen reservoir receives its water from an extremely steep and rugged catchment basin of 481-square-kilometre (186 sq mi) in the Alishan Range of south-central Taiwan.

[18] In August 2009, Typhoon Morakot caused massive flooding and mudflows which carried 91,000,000 cubic metres (74,000 acre⋅ft) of sediment into the reservoir, almost instantly wiping out 13 percent of its capacity.

However, after Typhoon Morakot the Taiwanese government approved a NT$54 billion project to remove silt and conduct watershed restoration work at Zengwen, Wushantou and Nanhua reservoirs.

[20] In January 2018, a 1,260-metre (4,130 ft) long sluicing tunnel began operation at the base of the dam, allowing sediment from the bottom of the reservoir to be moved downstream.