ASF Logo

Arroyo Seco Foundation

News of the Arroyo


Don’t let El Niño fears increase Big Dig at Devil’s Gate





September 24, 2015 - The Pasadena Star-News and the San Gabriel Valley Newspapers takes a sound and sensible approach to flood management, unmoved by all the scare tactics and rumbling from the County Flood Control Districts.


Editorial Board


San Gabriel Valley Newspapers


Devil's Gate Dam in the Arroyo Seco. (Staff photo by Eric Reed)

Has any other yet-to-manifest-itself weather pattern in the history of Southern California — perhaps the world — ever been more blathered about than the coming of El Niño?

It’s as if we’re all not just Fritz Colemans of KNBC but rather all Bill Patzerts of JPL, meteorological know-it-alls spouting constant cocktail-party updates on the surface ocean temperatures in the equatorial mid-Pacific and thereby predicting the precise amount of precipitation for the afternoon of Dec. 27.

And that day’s going to be a wet one, yesiree bob.

All the posturing notwithstanding, the warm ocean temperatures far off our shores do indeed seem to bode well for a rainier winter than usual in Southern California, as has been the case in past El Niño periods. That, as we all know, could be a good thing, given our state’s four-year drought.

But, as many of us know as well, it could be partially a bad thing, since too much rain can be almost as bad, or worse, in its own way as none at all.

The steepness with which the San Gabriel Mountains rise from the floor of the valley below them, where millions of us live, is very nearly unprecedented in geological terms anywhere on this Earth. The canyons above us are filled with boulders large and small that, along with walls of sludge-filled torrential waters, have come down out of the mountains with great destructive force in years past. The floods of late February and early March in 1938, so famously well-described in John McPhee’s book “The Control of Nature,” killed over 100 people in the Los Angeles basin, and brought car-sized rocks rolling down from the mountains in our foothills area in particular, from La Crescenta to Glendora.

That was the very same year in which, thanks to federal government funding of the Works Progress Administration, intended to make work during the Great Depression, much of our region’s flood-control channels were built, including the large concrete channel in the middle of the Arroyo Seco, from northern Pasadena to the Los Angeles River.

At the top of the channel, Devil’s Gate Dam had been erected beginning in 1920. Over the decades, sediment from the Upper Arroyo built up behind the dam, and periodically it must be removed in order for the dam to remain safe and effective. Los Angeles County last year approved a plan to remove 2.4 million cubic yards of debris over the next five years. Neighbors, environmental groups and the city of Pasadena saw that as dramatic overkill, with too many hundreds of daily dump-truck trips and too much destruction of the beautiful Hahamongna Watershed Park behind the dam that finally has been allowed to flourish after decades of use as an ugly quarry. The city and the Arroyo Seco Foundation, founded by Charles Lummis in 1905, along with the Pasadena Audobon Society, suggest a more prudent removal of 1.1 million cubic yards instead.

Now some are using trumped-up El Niño fears — “floodwaters could reach the Pasadena Freeway miles downstream!” — to demand an even more dramatic, environmentally destructive approach to debris clearance. Perhaps they hope to undercut the persuasive arguments that are set to be heard Dec. 8 in Los Angeles Superior Court by plaintiffs in a lawsuit against the county decision to go ahead with the planned Big Dig at Devil’s Gate. It’s a ham-handed approach not backed by engineering reality, and should be ignored.

The editorial board supervises the Opinion pages for the Los Angeles News Group's nine publications: Los Angeles Daily News, Long Beach Press-Telegram, Torrance Daily Breeze, San Bernardino Sun, Inland Valley Daily Bulletin, San Gabriel Valley Tribune, Pasadena Star News, Whittier Daily News and the Redlands Daily Facts. Reach the author at or follow The Editorial on Twitter: @SoCalOpinion.




Arroyo Seco Foundation, 570 W. Avenue 26 #450, Los Angeles, CA 90065-1011
PO Box 91622, Pasadena, CA 91109-1622 (323) 405-7326