Shigang Dam is a water-conservancy facility on the middle reaches of the Dajia River in Taichung's Shigang District, completed in October 1977 to supply public, industrial, and agricultural water to the greater Taichung area. During the 1999 921 earthquake, the Chelungpu Fault ruptured directly through the dam body, lifting the left bank 9.8 meters and the right bank 2.2 meters — a stark vertical offset that severely damaged spillway gates 16 through 18. Part of the displaced dam section was preserved after the disaster as an earthquake-education landscape, making it a rare site where an active fault visibly cut through a major hydraulic structure.
Shigang Dam was completed on October 15, 1977, according to the Water Resources Agency's Shigang Dam Management Office. At 1:47:12.6 a.m. on September 21, 1999, the magnitude-7.3 921 earthquake ruptured the Chelungpu Fault directly through the dam body, lifting the left bank 9.8 meters and the right bank 2.2 meters, and deforming the drive shafts of spillway gates 16, 17, and 18.
Highlights of Shigang Dam
Shigang Dam was built in the middle reaches of the Dajia River, completed in 1977, and its primary function is to capture and supply water to Taichung residents. On September 21, 1999, the magnitude-7.3 Jiji earthquake triggered surface rupture along the Chelungpu Fault, which happened to pass directly through the dam body, causing the two sections to shift vertically by about 9 meters, with portions of the structure damaged. Post-earthquake reconstruction bypassed the fault zone to restore water supply functions, while the offset dam sections were preserved for geological and earthquake education.
At the site, the two sections of the dam with their pronounced height difference are clearly visible — direct physical evidence of surface rupture caused by the 921 earthquake, carrying significant geological and historical value. The surroundings also include reservoir scenery with an open view, making this a combined natural and historical attraction in Shigang District.
How to Make the Most of Your Visit
Practical Information
Getting There & Timing
- Check with the Taichung City Government for current opening hours and access rules for the viewing areas around Shigang Dam, as some areas may be restricted.
- Drive along Provincial Highway 3 to Shigang and follow signs to the dam. Public transit is infrequent; self-driving or hiring a car from Fengyuan is recommended.
Nearby Connections
- Nearby attractions include the Dongshi Forestry Culture Park and Fengyuan Ciji Temple, which can be combined for a mountain-line history and culture day trip.
- The route can be extended to Guguan Hot Springs for a complete eastern mountain-line itinerary.
Source: Taichung City Government Water Resources Bureau, Wikipedia entry on Shigang Dam. Photos to be replaced with Dio's own shots.
Frequently Asked Questions
When was Shigang Dam built?
Shigang Dam was completed in October 1977, serving as a key water-conservancy facility on the middle reaches of the Dajia River.
How much did Shigang Dam shift during the 921 earthquake?
During the 1999 921 earthquake, the Chelungpu Fault ruptured through the dam, lifting the left bank 9.8 meters and the right bank 2.2 meters.
Is Shigang Dam still in operation?
Yes, the dam was repaired after the earthquake and continues to supply public, industrial, and agricultural water to the greater Taichung area, while part of the displaced structure remains as an earthquake memorial.
Sources
- 石岡壩災損情形－經濟部水利署石岡壩管理所 — 官方公布921地震壩體垂直錯位公尺數與閘門損壞情形
- 石岡壩－關於石岡壩－經濟部水利署石岡壩管理所 — 官方公布壩體完工日期與主要功能
- 石岡水壩－維基百科 — 背景沿革交叉核對