In new plan for Arroyo Seco, a real river runs through it: Larry Wilson
|November 22, 2016 - Larry Wilson describes the new plans recently unveiled at a meet in Pasadena to restore the natural character of the Arroyo Seco stream and canyon.|
The Rose Bowl and the concrete flood-control ditch beside it in the Arroyo Seco. (Photo by Walt Mancini/Pasadena Star-News)
In their early days of fighting the concretization of Southern California’s seasonal riverbeds, environmentalists often considered the Army Corps of Engineers the enemy.
The pave-everything mentality of the Corps and of both county and local public works departments was at odds with the effort to restore and naturalize the rivers.
Now, the activists and the engineering bureaucrats are finding common ground.
Though they may be as ugly as Brutalist architecture, rivers such as the Arroyo Seco were turned into flood-control ditches in the early and middle decades of the last century to save both human lives and development. In the past, dozens of lives were lost when huge boulders came tumbling out of the mountains that ring the north side of neighborhoods from Tujunga east to Glendora during periods of intense rain. A February 1914 flood in the Arroyo Seco destroyed 10 bridges and 30 homes, with over $5 million in damage and 43 lives lost. In 1917 a proposed Devil’s Gate Dam was the single issue in a county flood control bond issue; the dam was dedicated in June 1920, the first built by the Los Angeles County Flood Control District. But a 1938 winter flood almost destroyed the still-new Rose Bowl stadium; later that year, over two miles of the river channel down the middle of the Arroyo was paved as part of a giant WPA project.
So, good work, keeping us safe and sound and allowing for the creation of the built-out Southern California we know. But these things go in cycles. For more than three decades I’ve been writing about the ongoing tensions between those backing pavement and those for more green space in the Arroyo. And now, just as at its confluence near Chavez Ravine with the Los Angeles River, the two sides are working together to find common ground.
Last week, in a Pasadena Public Works Department conference room, representative from the Corps of Engineers and the nonprofit Arroyo Seco Foundation gathered along with about 100 interested residents to learn about the Corps’ program to restore the Arroyo Seco ecosystem. The plans, according to the ASF, include “varied approaches to restoring 11 reaches of the Arroyo Seco from the San Gabriel Mountains down to the Los Angeles River. The basic proposals include full stream restoration, low-flow natural bottom stream channels, the removal of invasive species, and subsurface concrete box culverts to carry flood flow.”
Amazing to even consider the flood-control channel we have all grown up knowing as instead a real river, one with “reaches,” like some Sierra trout stream. This is progress indeed.
The ASF reports: “While a lot of questions went unanswered, most participants seemed positive and even enthusiastic about what they saw and told the Corps and the county as much.”
The bottom line is that the Corps still has a nationwide responsibility to prevent human and economic loss from flooding. But it is now recognizing that concrete alone is not the solution. Several suggestions being reviewed could both take out some of the pavement and increase flood safety. Some of the plans being considered at various places on the river: Flood plain benching with full stream restoration and flood channel removal; low-flow streams with a natural bottom stream near the existing or modified flood channel; a natural bottom stream flowing through the Arroyo with the buried concrete culverts and the creation of pools and wetlands that provide good conditions for fish and aquatic species.
Steelhead trout, heading down from the San Gabriels and the Upper Arroyo Seco all the way to their ocean spawning, and then returning? That’s always the Southern California goal. It could even happen, long about our great-grandchildren’s time.
But the plans being looked at now could see riparian habitat restoration of up to 136 acres in the Arroyo, and that’s great news for the ongoing work to recreate an urban canyon in which recreation along the lines of hiking, fishing and bird-watching is given the same priority as swimming pools, cycling, golf and football.
In coming months, the Corps is set to select a plan, issue a report next year, seek federal funding in 2018 and begin construction — or is it destruction? — in 2021, all in the service of a revitalized Arroyo we deserve.
Arroyo Seco Foundation, 570 W. Avenue 26 #450, Los Angeles, CA 90065-1011
PO Box 91622, Pasadena, CA 91109-1622 (323) 405-7326 firstname.lastname@example.org