Shiraiwa Weir

Shiraiwa Weir is a flood control structure on the Joganji River in Toyama Prefecture that works together with seven smaller counter dams to regulate water flow and manage debris. The dam system forms multiple barriers that slow the river and protect communities downstream from the Tateyama Caldera.

The weir was completed in 1939 after ten years of construction work using advanced equipment like concrete mixers and mobile cranes. Engineers had to solve significant challenges posed by the steep mountain terrain where the structure was built.

The structure represents Japanese engineering excellence in water management, demonstrating the balance between infrastructure development and environmental preservation in mountain regions.

The structure is visible from designated viewing areas where you can see the dam and the river system from above. Clear weather provides the best view of how the multiple barriers work together across the landscape.

The weir uses an advanced monitoring system with optical fiber cables and cameras that collect real-time data during earthquakes and landslides. This technology allows operators to respond quickly to natural hazards and track the stability of the entire structure.

Location: Toyama Prefecture

GPS coordinates: 36.54861,137.53444

Latest update: December 10, 2025 16:30