Dajia River () is the fifth-longest river in

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

located in the north-central of the island. It flows through

Taichung City Taichung (, Wade–Giles: '), officially Taichung City, is a special municipality in central Taiwan. Taichung is Taiwan's second-largest city, with more than 2.85 million residents, making it the largest city in Central Taiwan. It serves as th ...

for 142 km. The sources of the Dajia are:

Hsuehshan Xueshan or Sekuwan (in Atayal, formerly known as among others) is a mountain in the Heping District of Taichung, Taiwan. It is the 2nd-highest mountain in Taiwan and in East Asia, at above sea level. It is located in the Shei-Pa National ...

and

Nanhu Mountain Mount Nanhu () is a mountain in Taroko National Park, Heping District, Taichung, Heping District, Taichung, Taiwan with an elevation of 3,742 m (12,277 ft). It is the 5th highest mountain in Taiwan. Nanhu Salamander (''Hynobius glacialis'') ...

in the

Central Mountain Range The Central Mountain Range is the principal mountain range on the island of Taiwan. It runs from the north of the island to the south. It acts as a barrier between the east and west coasts, hindering travel. The tallest peak of the range is ...

. The Dajia River flows through the Taichung City districts of Heping, Xinshe, Dongshi, Shigang, Fengyuan, Houli, Shengang, Waipu, Dajia, Qingshui, and Da'an before emptying into the

Taiwan Strait The Taiwan Strait is a strait separating the island of Taiwan and the Asian continent. The strait is part of the South China Sea and connects to the East China Sea to the north. The narrowest part is wide. Names Former names of the Tai ...

. Taiwan's

Central Cross-Island Highway The Central Cross-Island Highway () or Provincial Highway 8 is one of three highway systems that connect the west coast with the east of Taiwan. Construction The construction of the Central Cross-Island Highway began on July 7, 1956 and was ...

runs along the Dajia River from Heping to Dongshih. The Taichung Beltway begins in Fongyuan and follows the Dajia through into Cingshuei. The

mountain stream A mountain stream is a Stream, brook or stream, usually with a steep gradient, flowing down a mountainside. Its swift flow rate often transports large quantities of rock (geology), rock, gravel, soil, wood or even entire Trunk (botany), logs with ...

s of the upper Dajia River are the only habitats of the critically endangered landlocked Formosan salmon.

Hydroelectricity

The Deji Reservoir (), formed by

Techi Dam Techi Dam () is a concrete thin arch dam on the Dajia River in Heping District, Taichung, Taiwan. Forming the Techi Reservoir (德基水庫), the dam is built in the Tachien Gorge in Heping District, providing hydroelectric power, irrigation wat ...

, is a 592-hectare reservoir in Dajia District. The reservoir provides municipal

drinking water Drinking water or potable water is water that is safe for ingestion, either when drunk directly in liquid form or consumed indirectly through food preparation. It is often (but not always) supplied through taps, in which case it is also calle ...

, generates

hydroelectric power Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

, is used for recreation and prevents flooding. Techi and a cascade of five other dams on the Dajia (in sequence from hill top, the

Qingshan Dam Qingshan Dam () is a concrete gravity forebay dam on the Dajia River in Heping District, Taichung, Taiwan. The dam is the second in a cascade of hydroelectric power plants along the Dajia River, and is located directly below the Techi Dam and u ...

Kukuan Dam Kukuan Dam () is a concrete thin arch dam on the Dajia River in Heping District, Taichung, Taiwan. The dam serves for hydroelectric power generation and flood control, and is the third in a cascade of hydroelectric dams on the Dajia River, being ...

Tienlun Dam Tienlun Dam () is a concrete gravity dam on the Dajia River in Heping District, Taichung, Taiwan. Built from 1952 to 1956, the dam is the fourth in a cascade of hydroelectric dams along the Dajia River, located upstream from the Ma'an Dam and do ...

Ma'an Dam The Ma'an Dam (, 'Saddle Dam') is a concrete gravity barrage dam on the Dajia River in Heping District, Taichung, Taiwan. The dam is the final stage of a cascade of hydroelectric power plants along the Dajia River and is located below the Tienl ...

and

Shigang Dam Shigang Dam () is a concrete gravity barrage dam across the Dajia River in Shigang District and Dongshi District of Taichung, Taiwan, located near Fengyuan District. The dam was built from 1974 to 1977 for flood control and irrigation purposes ...

) produce up to 1,100

megawatt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Work ...

s of hydroelectric power and generate more than 2.4 billion KWh per year.

Incidents

The Dajia experiences frequent

earthflow An earthflow (earth flow) is a downslope viscous flow of fine-grained materials that have been saturated with water and moves under the pull of gravity. It is an intermediate type of mass wasting that is between downhill creep and mudflow. The ...

s during

typhoons A typhoon is a tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere and which produces sustained hurricane-force winds of at least . This region is referred to as the Northwestern Pacific Basin, accounting for a ...

and heavy

rain Rain is a form of precipitation where water drop (liquid), droplets that have condensation, condensed from Water vapor#In Earth's atmosphere, atmospheric water vapor fall under gravity. Rain is a major component of the water cycle and is res ...

, damaging homes and breaking up roads, sometimes permanently. In September 2008, rains from Typhoon Sinlaku resulted in storm-swollen waters which washed away supports for a section of Houfeng Bridge (which links Houli Township and Fengyuan City), leaving six people dead. In June 2010, the bridge finally reopened to vehicular traffic after over NT$1.4 billion of reconstruction work.

References

Landforms of Taichung Rivers of Taiwan {{Taiwan-river-stub

Hydroelectricity

Incidents

See also

References