El Niño Doesn’t Correspond to L.A. River Flooding, La Niña Does

February 29, 2016 § 1 Comment

The interview as it appeared in Friends of the L.A. River's Current News nearly 20 years ago

The interview as it appeared in Friends of the L.A. River’s Current News nearly 20 years ago. Click to enlarge.

Something came up in a recent discussion I was having about current spate of U.S. Army Corps of Engineers make-work projects to degrade the L.A. River in the name of El Niño. If you haven’t seen it, the cutting vegetation and installing dirt-fill barriers along the edges of parts of the river, resulting in nutty bike path detours.

What makes me sad is that the L.A. River generally hasn’t flooded during El Niño years, but instead mostly during La Niña years.

I know this from an excellent interview that FoLAR bird expert Dan Cooper did with climatology professor Richard Minnich back in 1998. I ran excerpts from this in 2010 – a drier La Niña year with some big storms. Below is the whole article.

Talkin’ El Niño
An interview with Dr. Richard Minnich of University of California Riverside, by Dan Cooper

Richard Minnich is a professor of biogeography and climatology in the Department of Earth Sciences at UC Riverside. He has been studying weather patterns and landscape ecology in Southern California and Baja for the past two decades, and recently spoke with FoLAR’s Technical Advisory Board chair, Dan Cooper, in Riverside on March 6, 1998

Dan: Dr. Minnich, let’s begin with the basics – what causes flooding in L.A.?

Rich: Two components are involved, long-term and short-term causes. In the long-term, the ground has to get completely saturated by rain; water hitting dry ground won’t do a thing. Now, in the short term, it’s the hourly rates throughout the day that are important. These rates are what cause catastrophic flooding like we had in 1938.

Dan: What kind of rain are we talking about?

Rich: Ballpark rates, maybe 20 inches in a day in the Transverse Ranges (incl. the San Gabriel and San Bernardino Mtns.).

Dan: Twenty inches in one day? That’s typically what we get in a year.

Rich: In January ’43, it rained 20″ in the mountains, but it was on dry ground so nothing happened. Now downing the coastal plain where everyone lives, all that concrete has led to the potential for flash flood conditions – the water has nowhere to go but into the channels. But even without concrete, major floods are possible – the floods in ’38 occurred before the whole plain was concrete and the rivers were completely channelized.

Dan: So 1938 must have been a big El Niño year…

Rich: Pretty neutral, actually. Neither El Niño nor La Niña conditions were recorded that year. Another neutral year was the winter of 1966-67 – the Transverse Range got 30 inches in December of ’66. The Transverse Range got 30 inches in December of ’66.

Dan: So El Niños don’t coincide with flooding in the L.A. Basin?

Rich: The three spectacular El Niños we’ve seen this century have been 1940-1, 1982-3, and again in the past season [1997-8]. Not one of them caused extensive flooding in the basin.

« Read the rest of this entry »

Hurricane Sandy’s Jersey City Debris Line

November 2, 2012 § 6 Comments

(Note to L.A. folks: this former L.A. resident is now spending time living with my fiance in Downtown Jersey City. I’ll be posting occasional east coast pieces that I think may be interesting to L.A.’s Creek Freaks. For more information on recent changes at LACF, see this earlier post.)

I’ve spent the last month living in Jersey City, a place that was hard-hit by Hurricane Sandy. I am not going to go over all the damage done by Sandy nor the environmental factors likely responsible for second “storm of the century” in two years here… but I wanted to share one small observation about debris – because Sandy’s debris lines resemble those I’ve seen on the L.A. River after storms.

The good news is that my fiance and I are safe and dry, and suffered nearly no serious damage. We did have a day-long blackout, and train service is still out. Neighbors’ places flooded, but our basement stayed dry. At least right here on our street, near Hamilton Park in Downtown Jersey City, we got some strong winds but very little rain. The flooding issues here (and in nearby Hoboken, Manhattan, etc.) were the result of a surge of the waters of the Hudson River. The hurricane pushed water upstream, overflowing the banks and flooding low-lying areas. The surge added to already high-tide conditions on the Hudson – in this area a tidally-influenced river.

Hurricane Sandy’s debris line along a level contour at Jersey City’s Liberty State Park

After the storm, we bicycled around – stretching our legs and checking out downed trees and other damage. We frequently bike at Liberty State Park – a low-lying park along the Hudson, just west of the Statue of Liberty and Ellis Island. The park has great views of the Manhattan skyline. The park contains the Liberty Science Center, located on a small hill. Along the base of the hill (see above photo), we spotted a debris line running along a level contour around the hill. The river pushed its flotsam as far as it could, and then receded, leaving a telltale line.  « Read the rest of this entry »

Upcoming Sediment Removal Meeting: Big Tujunga Dam

June 18, 2012 § 2 Comments

OK, thanks to Rick Grubb, I’m getting this with time for you to put it on your calendars!!

The County of LA is having a joint meeting with the USFS on sediment removal of Big Tujunga Dam.  Dirt’s all the rage here at LA Creek Freak, as you know.  Rick’s also communicated that he wants to see Arroyo Toad back in his region, one of many species that have been impacted by our flood control system.

Here’s the details:

Tuesday, July 24, 2012  6 to 8 p.m.
 
City of Los Angeles – City Council District 2
Sunland-Tujunga Field Office
7747 Foothill Blvd.
Tujunga, CA 91042 (map)
The United States Forest Service (USFS) and the County of Los Angeles Department of Public Works (DPW) will jointly present the Big Tujunga Reservoir Sediment Removal Project.  Information will be provided about the project, the National Environmental Policy Act (NEPA) and the California Environmental Quality Act (CEQA).  The public will have the opportunity to ask questions of the USFS and DPW and comment on the project.  Please plan to join us for this meeting.
For More Information:

Explorations of the Colorado River #4: The Design Studio

June 15, 2012 § 2 Comments

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Done with our touring of the Colorado River (1, 2, 3) and speed-reading about its issues, my 2nd year graduate landscape architecture design studio dove into planning and design solutions for the river.  In the analysis phase, over and over, it was observed that the river ecosystem needed to regain its flooding and sediment dynamics.  And over and over, it was observed that the political, human dimension would almost certainly never allow that to happen -regardless of the ecological desert created at the river’s mouth, and regardless of the obvious and dire future of the watershed due to climate change, population growth, and accumulating pollutants (including radioactive spoils behind reservoirs ya’ll!)

Clearly designing for what humans want usually comes at an environmental cost.  The ecosystem loses!  Even when it’s billed as sustainable, it’s more likely the design is about incrementally less harm to the ecosystem.  So in this studio, designers were challenged with having the Colorado River as their Client.  How do you work to meet human needs within that mandate?  It becomes a much different conversation.  Since many students don’t wish to explore “visionary” projects (visionary of course being the polite synonym for politically impossible, er, unrealistic), the studio was structured so that students could also provide concepts that inch us toward’s the River’s restored state, accommodating more of contemporary human uses while weaning us from an unhealthy allocation system.   This combination of visionary plotting (mwaahaha) and phased steps towards rehabilitation put together make for a nice master plan.

You can read more about the studio and download most of the studio’s presentations at When the River is Client:  Design Explorations of the Lower Colorado River.  I hope you will! There’s some great ideas the students came up with.

 

Sediment Management Strategic Plan Open for Public Comment Until May 30

May 15, 2012 § 6 Comments

20-Year Planning Quantities and Remaining Capacity at Sediment Placement Sites (Source: LADPW)

On the heels of a critical piece of writing by Emily Green on the state of sediment management in Los Angeles (published in the May 14th edition of High Country News), the L.A. County Department of Public Works has completed (as of April) its draft 20-year Sediment Management Strategic Plan for 2012-2032 and is currently soliciting public comments until Wednesday, May 30th. The enormous document (524 pages) is available for download at www.LASedimentManagement.com (the downloadable document entitled “Community Meeting Boards” is a conveniently concise summary of the larger plan). « Read the rest of this entry »

LA Creeks and Golf Courses – flowing by the fairways

March 26, 2012 § 6 Comments

It seems as though there’s almost always a creek on golf courses in Los Angeles – be it natural, concrete or underground.  And having proposed daylighting and restoration projects at a number of our local golf courses, I was happy to see this article, A Stream Runs Through It, published in the Golf Course Industry online magazine, supporting the idea.  I have found that golf courses and streams can coexist, but too often golf courses alter the stream, pushing it over the edge of the property, constraining it in ways that destabilize it, removing habitat, etc.  The management problems are often quite predictable.  The opportunity exists to design a golf course with an understanding of stream habitat and function, leading to a richer golf experience, fewer maintenance issues, and habitat for that remaining 5-10% of LA’s waterways.  Streams can separate greens, but when they traverse greens, they can become part of the play in interesting ways.

A couple of golf course/restoration locations I’ve referred to in Creek Freak posts include  Devil’s Dip (I promise a post on just the golf course and restoration potential there in the near future but here’s a slide from Creek Freak’s recommendations to Mark Ridley-Thomas about it.) and South Pasadena Golf Course.

A famous creek/golf course is the Arroyo Santa Monica through the Riviera Country Club in Pacific Palisades.  « Read the rest of this entry »

1938 Floods Film Footage

March 20, 2012 § 5 Comments

Click on image to view flooding video at archive.com

Thanks to Will Campbell for bringing this to my attention. Newly released film footage of the 1938 floods is online at archive.org. A lot of the neighborhoods are difficult for me to identify, but, at about 2:36 there’s footage of the downed railroad bridge at the confluence of the L.A. River and the Arroyo Seco. It looks like the shot is from the now-110 Freeway bridge looking upstream toward what’s now the Riverside-Figueroa Bridge. Check it out!

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