The Probable Impacts of El Nino on the Arroyo Seco Watershed

Thursday, Nov. 19, 2015, 7 PM
Altadena Community Center
730 E ALtadena Dr. Altadena, CA

A great crowd attended Separating Fact from Fear: The Probable Impacts of El Nino on the Arroyo Seco Watershed at the Community Center on November 19, 2015. Experts, including a Caltech geologist, analyzed the media hype surrounding El Nino, and looked at past El Ninos to help us understand the phenomenon, and why it is highly unlikely that major floods and destruction predicted daily will actually occur. Altadena Heritage co-sponsored this event with the Arroyo Seco Foundation.

The prospect of strong winter storms related to El Nino warming in the Pacific Ocean has led to a lot of speculation about what the local impacts will be. After the long drought, abundant rainfall would certainly be welcome, but potential flooding has also been widely discussed, often in simplistic and sensationalistic terms. All eyes are focused on Devil’s Gate Dam due to the long controversy about sediment management in Hahamonga Watershed Park.

“Separate Fact from Fear” will feature local authorities who will analyze the possible and probably impacts of strong storms in the Arroyo this winter. Participants will discuss the adequacy of the current flood control system, sustainable flood management, and how to best prepare for future flooding in the light of climate change. It is sure to be an educational and though-provoking evening, one with important lessons for a sustainable future.

Topics to be covered:

  • Previous El Nino Storms in the Arroyo
  • What about the Big Dig?
  • What We Can We Do Today?
  • How Can We Plan for the Future?
  • Probability of County’s Flood Scenario


  • Laura Garrett, Conservation Cahir, Pasadena Audubonasl
  • Tim Brick, Managing Director, Arroyo Seco Foundation
  • Mitchell Tsai, Esq. Attorney for Arroyo Seco Foundation
    and Pasadena Audubon
  • Marisa C. Paluci, Caltech Postdoctoral Scholar in Geology
  • Michele Zack, Altadena Heritage, Moderator or call 323-405-7326