Pacoima Dam

Pacoima Dam is a concrete arch dam that spans a mountain creek valley in the San Gabriel range. Its curved structure is wedged between canyon walls to hold back water and provide storage for the surrounding region.

The dam was completed in 1928 as one of the tallest arch structures of its kind in the nation at that time. This construction marked an important step forward in how the region managed its water supply.

The structure represents an engineering milestone in California water management, connecting multiple generations of Los Angeles County residents to their water resources.

The mountain location means visitors should expect winding roads to reach the site. Spring and autumn offer the best conditions for seeing the structure and the landscape around it.

The dam is monitored by seismic sensors that track its movements and have recorded how it responds to earthquakes. This data has become valuable for understanding how arch dams behave during shaking.

Location: Los Angeles County

GPS coordinates: 34.33470,-118.39600

Latest update: December 10, 2025 20:07