San Mateo County, California — The American Society of Civil Engineers (ASCE) recognized the Lower Crystal Springs Dam in San Mateo County, California as a National Historic Civil Engineering Landmark. Owned and operated by the San Francisco Public Utilities Commission, the dam was completed in 1890 and forms the backbone of a water system that serves more than one million people in northern San Mateo County and in San Francisco County.

“Water is our most important natural resource. It has defined where cities and communities are built, and changed the course of history,” said ASCE President Elect Feniosky Peña-Mora, Sc.D., P.E. “Innovative projects like the Crystal Springs Dam helped make the San Francisco Bay Area the thriving, vibrant community it is today, and its design helped pave the way for other dams, which have improved quality of life and access to drinking water for millions of people.”

Lower Crystal Springs Dam is the first mass concrete dam built in the United States and possibly in the world. The dam’s design and construction techniques became standard practice for other large mass concrete dams, including the Hoover and Grand Coulee Dams in the United States. The dam boasts a unique design. It is made of three-dimensional concrete puzzle pieces that make it resilient to earth movement.

“Despite being located a mere 1,000 feet from the San Andreas earthquake fault, this dam withstood both the 1906 and 1989 earthquakes with no significant damage,” said San Francisco Public Utilities Commission General Manager Dennis Herrera. “It’s not only an engineering marvel, it’s a crucial part of our system. We continue to invest in it to ensure it supports by people of the Peninsula and San Francisco for generations to come.”

ASCE represents more than 150,000 members of the civil engineering profession worldwide. It is the oldest national engineering society in the United States. ASCE recognizes historically significant civil engineering projects, structures, and sites all over the world. Fourteen National Historic Civil Engineering Landmarks have been designated in California. Lower Crystal Springs Dam is only the fourth project awarded in Northern California, joining the Golden Gate Bridge, the San Francisco-Oakland Bay Bridge and the Alvord Lake Bridge with such a distinction.

San Mateo County Parks Director Nicholas Calderon said, “the Crystal Springs Dam and Bridge are beloved landmarks offering scenic routes for recreational activities and critical connections for motorists, pedestrians, and bicyclists. We here in San Mateo County have always known it is special and we’re thrilled it now gets national recognition, too.”

Leaders of ASCE, the San Francisco Public Utilities Commission and San Mateo County recognized the landmark at a dedication ceremony on top of the dam.

About the American Society of Civil Engineers

Founded in 1852, the American Society of Civil Engineers represents more than 150,000 civil engineers worldwide and is America's oldest national engineering society. ASCE works to raise awareness of the need to maintain and modernize the nation's infrastructure using sustainable and resilient practices, advocates for increasing and optimizing investment in infrastructure, and improve engineering knowledge and competency. For more information, visit or and follow us on Twitter, @ASCETweets and @ASCEGovRel.