Historic Flood Photos

Valley Lows



Valleys are low lying, flood-prone areas between hills and mountains—and Tri-Valley refers to our location nestled among three valleys:

  • Amador Valley
  • Livermore Valley
  • San Ramon Valley

As such, the Tri-Valley has been subject to a number of floods over the years. Take a look back at our history of flooding below.


Christmas Eve flooding in 1955—two years before Zone 7 was created in part to provide flood protection—left much of northern Pleasanton, in the vicinity of where Hacienda Business Park now stands, under water. In 1983, Arroyo Mocho is shown here in Pleasanton with rising flood waters.


Throughout the 90s a series of rainy years caused flooding in Tri-Valley.

Learn more about how we are strategically managing our flood channels to help protect our homes and businesses in the future on our Flood Protection System page.