Dry weather diversions – memories up a sh*t’s creek

December 29, 2021 § 3 Comments

Yesterday’s post hurt my brain to write, and it hurts my brain a little to re-read. OK, it hurts my brain a lot. So I suspect it’s not fun for anyone else either. I wish it could be more straightforward.

And then I woke up this morning realizing I wasn’t done with the subject yet. Ugh.

So if this issue of buried streams in the crossfire of clean water regulations and local governments liable for compliance is pertinent to you, bear with me. If you live in a park poor area with buried streams (Angelenos, that’s basically you), it’s pertinent.

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A buried creek’s dilemma: to be daylighted or drained?

December 28, 2021 § 3 Comments

[Opening digression: I was just texted an image predicting rainfall for LA for the next few days – it looks like you could get hammered (rainfall-wise – what you do with alcohol I have no predictions for), so this post may seem ironic, misplaced, bad timing? You’ve got a trough heading your way and if it doesn’t keep moving…well let’s just hope that it does. The focus of today’s post is dry-weather flows…]


To those of us who recognize stormdrains (or, some of them) as body-snatched creeks, and who long for a water management approach that would incorporate daylighting or naturalization of concreted waterways and nature-based treatment that doubles as streetside landscaping, floodable parks, greenways, etc., well, prepare to be disappointed. Or enraged? Whichever, it’s a familiar feeling. At least we’re not alone on this.

The City of LA recently issued an IS/MND (Initial Study/Mitigated Negative Declaration) and awarded a contract to start work on diverting low flows from certain stormdrains. The low flows – aka urban slobber in some circles – would be pumped from the storm drains into the sewer system, so that they can be treated for pollutants. From there, like the rest of the region’s wastewater, it either gets discharged into flood control channels rivers, is infiltrated to groundwater, or reused (such as purple pipe irrigation). So you can see how it closes some loops and ticks some sustainability boxes.

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15 minutes for Creek Freaks and the waterways we love

November 15, 2021 § Leave a comment

We are having a moment in the spotlight! Alta Online journal recently published a great story, Soaked Through, about LA’s waterways and some of the people who love them. I encourage you to give it a read! Writer Denise Hamilton covered a lot of ground about LA, its streams, relationship to groundwater and then some – and her work updated me on some happenings that I may rant about here sometime. (As longtime readers know, I promise such things but the time to deliver is hard to find.)

That said, Alta invited fellow CF Jane Tsong and I to participate in an online panel which will be this WEDNESDAY at 12:30 PST!

You can register for the event HERE. Join us!

While I’m talking about great recent articles, another beautiful one by writer Judith Lewis Mernit, who periodically visits river and creek topics, can be found at the Red Canary Collective. It is a fine read, a clear a clarion call for a different way of thinking about our waterways. Send it to all your elected officials!

About that Dominguez Stench

November 5, 2021 § 19 Comments

I’ve really been trying to resist the urge to talk about the Dominguez Channel’s horrible stench. Driving through it when I was down visiting family recently, I understood that nothing I can say will make it better. It is absolutely noxious. I can’t imagine being stuck in that.

But long-ago angelenos of the past can.

Historically the slough that is today’s Dominguez Channel was a broad flat wetland. It had another name, a racist slur, and we’ve written about that before.

George Bixby described the very marshy landscape of the lower San Gabriel and Los Angeles Rivers, Compton Creek and Dominguez Channel Slough areas, as it existed before American occupation:

“I once had a Mexican vaquero whose father had lived there all his life who said that all the valley between Los Cerritos, Dominguez and San Pedro was one tangle of marsh willows, larch, blackberry vines, and other tangled undergrowth which was impenetrable. There was only one or two trails across the valley, and they were not safe for two reasons: on account of the undergrowth and bogs, and there were bears in the tangled jungle.” – G.H. Bixby, 1914

(By the way, he meant grizzly bears…I know, right??!!)

Groundwater was high in this area, replenished by frequent flooding. Groundwater pumping and leveeing and culverting of waterways resulted in a shrunken perimeter of the wetland that would fatten up again with rains. And parts of the LA area that is today’s Gardena, Torrance, West Athens, Compton, parts of Hawthorne and Lawndale, Carson etc was this slough, or converted to farmland around it. The Gardena Willows, Madrona Marsh, “Devil’s Dip” at Chester Washington Golf Course, and a wetland inside a mobile home park are what remains of the over 1,200 acres of wetland (in 1900). Oh, and it’s probably been destroyed by now, but also a seasonal wetland in Torrance… Alondra Park sits on land that was part of the wetland, but nothing about it (as far as I know) is ecologically related. Victoria Regional Park/Golf Course in Carson were also part of it – a soft bottom reach of Dominguez Channel is what remains – but that site also has toxic cleanups in its midst. More about that later. Nice parks, though.

Wetlands are beautiful, but sometimes stinky, things. They have slow-to-not moving water and decomposing vegetation. As that veg sits there, over the years, it can create “swamp gases” as it breaks down. But even that isn’t what made the stench at the former slough memorable to people, who, in 1914, clearly recalled the Great Yuck of the 1890s. Humanity played a role in creating it: Apparently carp were a popular fish to stock in ponds back in the day. And humans being what we are, people weren’t thinking about consequences, so when it rained, the fish just washed into the wetland. After large rains in 1889 expanded the girth of the slough, the fish population expanded with it. And shoulders shrugged.

Then the drying started.

“the people imported a lot of carp about 1878-79 and everybody that had a lake or pond got some carp and stocked them up and in 1889 was overflowed and their ponds washed out and the fish were carried down to…(the) Slough and when (the) Slough began drying up some years later the fish commenced dying and made such a stench the supervisors had to hire men to clean them up and burn and bury them. – J.J. Morton, 1914

“…One noticed a dreadful stench coming from the direction of the…slough and it was found that the slough was drying up and leaving tons and tons of dead carp fish rotting in the mud. People went there and hauled away wagon loads of the fish for fertilizer and other purposes. Finally it became so bad that people began to leave Long Beach, and an appeal was made to Supervisors for relief. Trenches were dug and a great amount of the fish were buried – A.C. Cook, 1914

James P Reagan, County Flood Control Engineer, collected multiple accounts of this event in his document Early Floods in Los Angeles County (1914). (Creekfreak likes to quote this document. Here’s a few places…) Yet this wasn’t the only non-industrial stinky gross wetland horror story in LA’s recorded history. As we all know too well, LA’s rainfall patterns tend to be all-or-nothing. And LA used to be ranching country. So again with wetlands expanding and contracting:

In 1863-64 there was an awful drought and there were thousands of head of cattle and horse died. Going to Wilmington you had to tie something over your nose on account of the stench along the San Gabriel and Slough. You could walk for miles on dead cattle. The whole slough and river down below Bixby Hill was full of them. There were fifty men skinning cattle and there were boat loads of hides stacked up. There was no rain at all that season and feed was so short that the cattle got so weak when they would go down to the river and slough for water they would get in and mire down and were too weak to get out. -John Guess, 1914

This happened throughout the Ballona country, as well as the the Dominguez and lower San Gabriel areas. Hard to imagine, eh? (Not if you’re in Carson.)

Long story short: I don’t really have a point, except: ew.

Well, actually –

When I read that County Public Works was saying that the stench on Dominguez Channel was “natural”, part of me wanted to rear up and defend poor little Dominguez. There’s not much about it that is natural anymore. I’m sure that part of what is happening is because of the drought, and decay of whatever is on the bottom of the channel. Arguably “natural” in an otherwise wholly unnatural system. But it took “tons and tons” of dead carp in a 1200+ acre wetland, to create the level of sick that drove the residents of Long Beach away. So how many dead things would have to be in the Dominguez Channel right now to create the level of sick that is sickening Carson (and Gardena, where I smelled it)? Is there evidence of those dead things? Who knows if there are other factors, like industry, as some residents have wondered.

I don’t think it’s far from anyone’s mind that this is a community of color that is primarily impacted by this stench. And if you’re a thinking person, you have probably also made a mental note of all the heavy industry within spitting distance of many residents in the greater Dominguez watershed. If you pay attention to the news, the stories, for example of industrially contaminated soil in these areas that periodically pop up in the news are rather plentiful: for example, here, here, here…stop already you cry! But there’s so much more to show you – just take a whirl through the Department of Toxic Substance Control’s Envirostor.

Here’s a teaser:

So, these are communities that are deeply screwed.

That level of zoominess yields the same response in most of the LA Basin, to be fair. But when you scroll over to the IE or Ventura, it will display at that scale (=less screwed?). So, here’s a zoomed-in screenshot of part of the historical area of the Dominguez Slough:

Still screwed.

The Mapping Inequality project (screenshot below) showing how the New Deal government redlined the country offers additional insight. The slough still existed (offensive name intact), and the land around it was still being farmed, with housing – much of it described as oil workers and farm hands – in the “hazardous” (to lenders) redlined communities around it. Hawthorne where I grew up is just off the image, also “hazardous”, mainly due, apparently, to the presence of “Mexicans, Japanese, & Italians”.

Ironically(?), redlined ol Hawthorne was, before my time, a sundown town (as were many LA communities) and I recall how like the John Birch Society so many of our white neighbors sounded. And redlined Torrance was, in my youth, a pretty racist place. Which is a roundabout way to say, you can poke holes in correlations in the South Bay, between wetlands and industrial development and redlining and systemic racism. But, having lived there, I think the overall trend holds. And that, beyond the gross-out factor of stenches past and present, is what races to the fore of my mind as I follow the ongoing saga there.

Truths universally ignored: wetlands and floodplains are not great places to build. Yet instead of seeing them as ecological and hydrological resources, we see them as “wastes” and then treat them as such. Then we said that scapegoated peoples couldn’t live in the nice places, and left them to make homes on these “marginal” lands. Government helped to make so-called waste land usable, and industry – which wouldn’t be welcome in the “nice” places – sets up shop. You know this, I know this, people at whatever city hall you visit know this. But it happens anyway…

And as far as environmental racism and watersheds goes, it’s is an iceberg of an issue and we’re just looking at the tip. Oh, and: that iceberg is melting. Let’s talk about floodplains and race.

Fun Silly New L.A. River Kayaking Video

December 10, 2019 § Leave a comment

Enjoy this new video from a couple of intrepid folks who recently attempted to kayak the L.A. River… and didn’t get very far… but nonetheless made a fun video showing their experience. They put in near Griffith Park’s Bette Davis Picnic Area – at the edge of the city of Glendale’s Glendale Narrows River Walk and only got to the adjacent Griffith Park Ferraro soccer fields.

There are plenty of places to put in and kayak the L.A. River safely and enjoyably – see my 2008 account of my first kayak trip there: day1, day2 and day3. The Burbank and Glendale stretches do involve plenty of portaging (walking.) There are also various organized kayaking tours these days. One warning: the L.A. River can get very dangerous very quickly during rainy weather, just watch No Way Out. The best time to kayak is when it’s not raining.

The watershed in your yard: the WaterLA 2018 Annual Report

February 23, 2018 § Leave a comment

waterlacover

Books! OK… well – Reports! Part 3, the final of my recommended reads – the practical, the lyrical and

The Celebratory (also, yes, the Nerdy): Water LA 2018 Report

WaterLA , a project spearheaded by the River Project, champions making watershed management local. Hyper local. Your front yard local. The team there combines community outreach with effective, tested permaculture and landscape design techniques to harvest and retain water in yards and street planting strips. Rain gardens, rain barrels, grey water systems and permeable paving are among the solutions used at multiple sites across LA’s Valley. WaterLA organizers locate community members ready to pitch in and engage in work parties, so that everyone’s working together – building community while building resilience.

This year’s WaterLA Annual Report, then, is a celebration of the gains to individuals, families and our water supply delivered through participation in the project. You see, all those small projects add up to groundwater enhancement, and reductions in peak runoff when it rains – dampening the effect of most floods. The Annual Report quantifies water savings and relates project costs to other, more costly, regional approaches currently in use. Native plant and permaculture folks may be excited to see the conversions of lawns to habitat and foodscapes, community-minded folks may find some inspiration in its projects, and fiscally-minded folks may be encouraged to see creative, affordable solutions to expensive regional problems. A worthy project that would benefit all if it could be applied on a larger scale.

Check it out.

Restoring Neighborhood Streams: a book that LA could use

February 19, 2018 § 9 Comments

Maker:L,Date:2017-9-16,Ver:5,Lens:Kan03,Act:Kan02,E-Y

Creekfreaks! If you, like me, have resolved to pull away a bit from the netflix-amazonprime-hulu bingefests that serve as a daily nonpharma escapist (are we really living these political times?) opiate, and if maybe you, like me, are rediscovering those magical things called books – then I have a few reads for you! They range from  practical, to lyrical, to celebratory. Personally, I find them all inspirational. In today’s post, I give you –

The Practical: Restoring Neighborhood Streams; Planning, Design, and Construction

Restoring Neighborhood Streams; Planning, Design, and Construction (2016, Island Press), builds on author A.L. Riley’s decades of engagement and effort in the restoring and daylighting of streams in urban and suburban areas. This Creekfreak was especially influenced by Riley and her work. Her previous book, Restoring Streams in Cities, is well dog-eared in my library, and has been an important go-to reference for how to think about stream function and restoration design. This new book provides case studies that illuminate fundamental questions that should be the basis for planning and design of urban stream restoration:

  • Is it physically feasible to restore?
  • Is it financially feasible?
  • Does the public support (I’d add: political will) exist to support land use changes to support a live river or stream?

« Read the rest of this entry »

In every bottle, a creek…

February 2, 2017 § 4 Comments

arrowhead-bottle-with-springs-list

Next to the snow-covered mountain on each Arrowhead bottle, is a list of “mountain springs” within.

The Arrowhead landmark in the foothills of the San Bernardino Mountains.

The actual Arrowhead landmark in the foothills of the San Bernardino Mountains.

In every bottle of water is a creek, and there is actually a good chance it may be a California creek, as the map in this link indicates: “Lots of your bottled water comes from drought zones.”

This is something I think about every day when I walk by the water dispenser at my office. I look at the snowy mountain top on the label, and mentally compare it to the actual Arrowhead landmark, in the foothills of the San Bernardino Mountains, which I drive by each week. This iconic landmark is made of coastal sage scrub plants: white sage, black sage, california buckwheat, and others (Meek, 2007). Ironically, what makes the arrow stand out from the surrounding chaparral is the grey foliage that advertises the ability of these plants to survive drought.

Our remaining native ecosystems hang on a very delicate balance, and surface water and groundwater play an important role in maintaining this balance. This is just one of the reasons I feel alarmed when I see the list of “mountain springs” listed on the side of Arrowhead bottles. Because I suspect the other places on this list do not look anything like the snow-covered mountain on that label!

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Steve Loe, a retired San Bernardino National Forest biologist, speaks to a packed house.

Last Sunday, I went to a community hearing sponsored by The League of Women Voters and Save Our Forest Association to learn how Nestlé’s extraction of water from the San Bernardino National Forest impacts Strawberry Creek, its riparian ecosystems, and our local groundwater. Speakers addressed a packed house at the Senior Center in Twin Peaks.

Strawberry Creek is the creek associated with Arrowhead Springs, after which Arrowhead water is named. It is located in the foothills of the San Bernardino Mountains.

Over the last 68 years, Nestlé extracted an average of 62 million gallons per year from wells drilled into the upper watershed of Strawberry Creek. According to figures presented at the hearing, this is over 5% of the safe yield of the entire San Bernardino Basin, which supplies the cities of San Bernardino, Riverside, Redlands, and others. Even in the midst of a multi-year drought, in 2015, Nestlé extracted 36 million gallons.

Nestlé’s extraction of millions of gallons per year occurred even as residents and businesses were required to restrict their own water usage.

For this amount of water, the company paid only $524 each year. One speaker said this came out to $3.65 per acre-foot of water, which the company then sold for 100,000 times that amount.

36  million gallons extracted in 2015, in the midst of a multi-year drought, means that much water did not make it to the creek. This means all of the plants and animals that once lived in the creek are short that much water.

Loe made it clear that the “mountain springs” of Strawberry Creek are not artesian springs which leap out the ground. Rather, they are horizontal wells drilled over 500 feet deep, maximizing groundwater extraction in the creek’s upper watershed, before water even gets to the creek. The drill sites are so dry that no riparian vegetation appears in their vicinity.

Nestlé claims to only extract water that is in ‘excess’ of the Forest Service’s current and foreseeable needs.

Given the outsized importance of riparian habitats in contributing to local biodiversity and providing regional ecological connectivity,  Loe asked, can one say there is excess water when a creek is close to its lowest flows on record? Species that depend on riparian habitat are at low population levels, and others historically associated with the San Bernardino Mountains, have disappeared. Loe believes Nestlé’s extraction of groundwater was a contributing factor in the disappearance of Santa Ana speckled dace, a native fish species, from the area after 2003.

In a statement by the Center for Biological Diversity, the Story of Stuff, and Courage Campaign Institute, Eddie Kurtz wrote, “The U.S. Forest Service has been enabling [Nestlé] to destroy delicate ecosystems in the San Bernardino National Forest for 27 years, and it has to stop. Our government won’t stand up to them, so we’re taking matters into our own hands.”

List of demands, where "FS" means "Forest Service."

A list of demands. Note that “FS” means “Forest Service.”

 

FOR MORE INFORMATION

The co-sponsors of Sunday’s hearing: League of Women Voters of the San Bernardino Area.

I always love the Desert Sun’s coverage of environmental issues: Bottling Water without Scrutiny.

Meek, N. (2007). Origin of the Arrowhead landmark near San Bernardino, CaliforniaCalifornia Geographical Society.

asdf

Found in the San Bernardino Mountains…

Coyote Spring, Inyo County, one of the springs listed on the Arrowhead label.

Coyote Spring, Inyo County, another of the springs listed on the Arrowhead label.

Of chenopods and corn: agriculture along the Los Angeles River, both then and now

July 27, 2016 § 5 Comments

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In the very early days of agriculture in the Los Angeles basin,  the seasonal flooding of the Los Angeles River was intimately connected with the possibility of agriculture. Farmers welcomed flood-deposited silt. It made stuff grow. The agriculture of then grew out of the river of then.

The agriculture of now also deserves to be discussed in the context of the LA River, though  it may require some serious visionary thinking to draw out the possibilities of this connection. Some have suggested the idea of community gardens along the river. Maybe in the near future. But let’s not forget that in the river as it currently stands, there are already all sorts of useful or edible plants that grow profusely without labor, chemicals, or other inputs. What can we learn from those plants?

Last of all, how can we put together the past and present to envision ways in which sustainable local food production might intersect with the Los Angeles River of the future?

At L.A. River Expeditions‘ Sepulveda Basin tour this past Sunday, kayak guide Gary Golding talked about useful wild plants currently found along the LA river channel, such as cattails, castor bean, wild mustards… Some of these plants are exotics and some are natives. Some are edible, and others are used medicinally. But what they all have in common is that they grow profusely and unapologetically, without the help of chemicals, irrigation, or the human hand, in any place suitable to their needs. This includes right in the Los Angeles River channel, where they thrive beneath a lush canopy of native willows. So why not learn what they are and learn how to use them?

Gary talked a long time about cattails. Parts of the plant can be processed into flour. Other parts can be eaten like celery. The pollen can be used in several different ways, and is considered to have healthful properties. This is just a brief capsule of one of the many plants he talked about.

My own talk started with the agriculture of then. Believe it or not, in the early days of (European) settlement in the basin, the soil in many valley areas of Los Angeles used to retain enough moisture to allow for farming without irrigation— this is called dry farming. Ludwig Louis Salvator wrote in 1876 of the “tablelands” of Los Angeles, that properly prepared soil could produce “nine good annual harvests out of ten, without irrigation, of castor oil beans, Indian corn, barley, alfalfa, potatoes, and various kinds of vegetables.”

At that time, the LA Basin was only sparsely developed. In that big open basin, plant roots and plant litter facilitated the soaking of water into the ground. Imagine about 50% of all rainfall ending up stored in the ground (California Water & Land Use Partnership), moving slowly downward through soil with the help of gravity, where it eventually joins the water table. In those days, rain moving slowly underground would have eventually re-emerged into one of the many streams, marshes, ponds, or wetlands in the LA River basin.

Though flooding did occur during the rainy season, it was different from the sudden devastating flooding of the early-mid 1900s– the flood stories we often hear about tend to be mostly from this specific period in history. This pop mythology about the river focusses on the kind of flooding that worsened in severity after houses and roads had already replaced the vegetation that had helped the ground behave like a sponge; the kind of devastating flooding that eventually prompted the channelization of the river into a thick bed of concrete… That kind of destructive flooding was still unknown. In the earliest days, rather, flooding was to be respected, but it also included the happy possibility that the river would deposit rich silt over the land, sometimes in layers several feet deep. Farmers loved this silt. The oral histories collected by Reagan in 1914 include many in which farmers praise the flood-deposited silt.

It was not necessary to fertilize the land, as they are now doing. They raised 100 bushels of corn to the acre, but not now. In those days a crop of corn and California pumpkins were raised on the same land. Those pumpkins would grow so thick that it was difficult to walkaround and step between them, while it was an easy matter to go all over the place and never step on the ground, stepping on the pumpkins. The largest I ever saw weighed 214 pounds, and on our place we raised one that weighed 206 pounds. (Proctor, from Reagan)

These stories might sound fantastical, but in his book on the Los Angeles River, Blake Gumprecht credits river-deposited soils as the reason Los Angeles County was “the most productive agricultural county in the United States until the 1950s.”

Contrast that to our current situation (call it the well-drained city), where 61% of the non-mountainous portions of the city of Los Angeles is covered by impervious surfaces, the hard surfaces like paving and roofs that prevent water from soaking into the ground (McPherson et al, 2008). Water moves very quickly over those hard surfaces, and is funneled into an elaborate network of stormdrains that transports captured rainfall as efficiently as possible into the ocean, rather than allowing it to soak into the ground where it might be replenishing aquifers, streams, and rivers.

On undeveloped land (this depends on slope, soil, vegetation cover, and other factors), one might expect 10% of rainfall to become surface runoff. In urbanized areas, about 55% of rain falling on the ground can become runoff that ends up in storm drains (California Water & Land Use Partnership). It is ironic that the finely networked stormdrain system that culminates in the  Los Angeles River flood control channel really functions to dispose of the water that otherwise would be creating our streams. (This is why any river restoration that focusses only on the main channel without touching the network of tributaries higher up in the watershed might look good, but is essentially an end-of-pipe solution– it will not have a large impact on the river’s hydrology– it will certainly not help the river capture more water.) With precipitation disposed of so efficiently, the landscape of the Los Angeles basin is now so well-drained that the idea of growing vegetable crops without artificial irrigation, even in the ‘table lands,’ might seem fantastical.

—–

What about the agriculture of now? As I spoke, some kayakers pointed out a field of corn planted right in Sepulveda Basin, near our trip’s starting point.

I had to investigate. Rows of corn were planted neatly,  but the stalks were wan and thin. The plants on the edge of the field were dried. Maybe irrigation had just recently ceased. I was surprised to see that the plant that gave the field a dark green color from a distance was actually a species that appeared to have volunteered. This plant, growing far more prolifically than the intended crop, appeared to be some sort of chenopod.  « Read the rest of this entry »

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 »

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