Getting to the Source: Water Quality on the L.A. River

August 11, 2016 § Leave a comment

That L.A. River water isn’t pristine isn’t exactly news. But Heal the Bay’s report this week, with measurements from last summer showing high bacteria content in the river, caused a stir. So what’s going on? We’d like to provide another perspective to better complete the picture and focus the discussion.

With river-connected activities like kayaking, fishing, biking and horseback riding increasing since the EPA’s 2010 determination that the entire L.A. River is to be protected under the Clean Water Act, people have figuratively, and sometimes literally, jumped in. The State Water Resources Control Board and the City of Los Angeles have noted that the river’s water quality was acceptable for activities like kayaking but stopped shy of recommending activities like swimming.

Opening up public access didn’t immediately get us to the point that FoLAR’s Lewis MacAdams had hoped for as a milestone goal for the river: “…a swimmable river.” That’s OK. Since 2010, we’ve taken some large steps forward.

Since 2008 we estimate that we’ve put more than 5,000 Angelenos on the river in our kayaking programs, and there hasn’t been a single reported case that indicated the types of health risks mentioned in the report.

Heal the Bay has made it clear that they do not want to impede the river revitalization process. They emphasized that the report (available here) should not stop anyone from river recreation—only that people should have proper warnings and use common-sense safety procedures.

Unfortunately, following the report there was a great deal of misunderstanding in the general public. Angelenos are accustomed to swimming at Santa Monica Beach or Mother’s Beach in the marina, which regularly get very poor water quality ratings from Heal the Bay due to high bacteria content. The conditions are worse after rain because of urban runoff. We’re all somehow okay with that, as bathers or surfers may get an ear infection or some other ailment, but then surprised when those same problems show up in our hometown river.

We face a systemic water pollution problem in Los Angeles.  « Read the rest of this entry »

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 »

Early Floods in Los Angeles: Interview 147, J. E. Proctor, Long Beach: It was not necessary to fertilize the land…

July 16, 2016 § 1 Comment

One of the best creek freak documents around is a series of interviews made by Los Angeles County Flood Control Engineer James Reagan, around 1914. The interviews give a vivid picture of the Los Angeles basin of more than 100 years ago. We will be posting other interviews from this document in the following months.

He has been in this section of the country for more than forty years, and has witnessed some big floods. They have never done the damage that the flood last winter did, for the reason that everything is different. In the early days, and up to within the last four years, the country was covered more or less with willows, brush fences, and in some places, lakes, marshes and other small growth. In those days the water would spread out all over the country, and the velocity was very much slower, it did no damage, and in many ways did good.

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.

So in this way the floods did a great deal of good. Each flood left a deposit of silt on the land that made the rich yields of those days. I am afraid the people will miss those floods, although in the last flood the land was washed very badly. That washing comes from the land being cleared off and having a freer run than before. There were no railroad embankments in those days either to hold the water either, where it is now held up, and the volume contracted into a smaller space at the openings under the railroad. And too, a flood would break out and a strong current would cut across the country carrying things before it, and in the wake perhaps putting a channel that ruined the land. Therefore part of the flood carried the big amount of silt, but the deposits were left by the last part of the flood.

On our place we have no fear of the flood that first comes, that does no damage, but it is the tail end of the flood that causes the damage. A place is started below us, and should a flood come again as last winter it will probably cut back and ruin our place. As it is we could do nothing with it this year; we could not rent it for anything.

Many peculiar things were noted in the flood of last winter. We had a chicken yard about 50 feet square, made of woven wire chicken fencing. On the inside of this fence, when the flood had gone down we found a deposit of sand and silt inside the yard about three feet deep. And another at a lower corner of the fence, a single strange of barb wire about 100 feet long, got loose except at one end, where it was held. Along this single strand of barb wire as it lay down stream had gathered a sand bar just back of the wire, or just below it, about 18 inches high.

These two things show what small obstructions can do. It gives us an idea of how little it takes to gather the silt, to form an obstruction that will soon turn the stream in some other direction.

So for a protection to the land I believe that a mat of willow roots and boughs would be more effective than anything else outside of a solid concrete wall and flood conduit for the water to travel in.

A channel 500 or 600 feet wide would probably carry the flood of last winter, but some of the others I could not say. The only objection to a wide channel is that when the tail end of the flood is running off it is liable to start zigzagging across the channel and then it is liable to cut the embankment. As long as the channel is clear and straight and enough water to partially fill the channel, everything would go all right, but the small stream that will not fill the channel will do a great deal of damage.

It is easy to get the willows to grow, they will grow anyway. The best way is to get branches as long as possible, lay them with the buts upstream, and then partially cover the with sand. They should be placed at the bottom of the embankment in the river bed, and then they will get plenty of moisture.

Mere sand banks will not do. They will melt down like sugar. But something should be done, but not any great expensive works until they work out the most effective methods of handling the water. I have worked in water all my life, and have seen some funny capers by it….

The second half of the interview, perhaps to be transcribed at a later date, describes the different qualities of well water at different strata.





Early Floods in Los Angeles: Interview 140, William Mulholland: It is no difficulty to do things when the work is carried on in harmony with Nature

July 15, 2016 § 7 Comments

One of the best creek freak documents around is a series of interviews made by Los Angeles County Flood Control Engineer James Reagan, around 1914. The interviews give a vivid picture of the Los Angeles basin of more than 100 years ago. We will be posting other interviews from this document in the following months.

The following is a transcription of Mulholland’s interview by F. Z. Lee, on October 2, 1914.

As Mr. Mulholland said, he has never had anything to do with the river other than in connection with the water works, where their supply came from for many years.

There seems nothing strange or mysterious about handling the floods of the river if the lesson from nature was followed. It is no difficulty to do things when the work is carried on in harmony with Nature, but when man begins to obstruct the laws of Nature and to work against them, then there is great difficulty.

We had no trouble with the Los Angeles River until 1877-78. Up to that time the channel of the river was clear of willows and other growth that would cause the water to change about from one side of the river to the other. When the floods came they spread over the gravel beds of the river and ran along smoothly without obstruction. There were some willows along the banks of the streams but none out in the channel. The channels remained the same all the time.

« Read the rest of this entry »

Resources for armchair creek freaks

May 18, 2016 § 1 Comment

Rattlesnake Island, 1896, USGS Historical Topographic Map Explorer

Rattlesnake Island, 1896, USGS Historical Topographic Map Explorer

When this blog first started, those of us interested in what our neighborhoods used to look like in the far past had to trek to libraries and archives all over town to find old maps, then figure out a way to photograph or scan the most useful. To understand how these maps related to the contemporary landscape, I used to superimpose scans of old maps over contemporary ones by using Adobe software- a slow, cumbersome, and inaccurate process!

Since then, there has been an explosion in the quality and quantity of map resources online. Best of all, some have already been georeferenced (digitally located in physical space), which means that anyone can very casually compare any neighborhood now to what it was 100 years ago by using a slider.

Here are some of my favorite places to look for old maps of Los Angeles:

USGS Historical Topographic Map Explorer   (click on the area of the US that you want to view, then choose a USGS map from the timeline to view)

William Hammond Hall’s irrigation maps at the David Rumsey Map Collection (some of the LA area maps have been georeferenced, but if you have the interest, anyone can contribute by georeferencing new ones….such as the one of San Bernardino pictured below)

Ballona Historical Ecology (Ballona Creek only)

Here is a modest effort of my own from way back, a synthesis of William Hammond Hall’s sketch of the North Branch of the Arroyo Seco with elevation data of the same area created in ArcGIS, then shared through the old Google Maps interface. It was a disappointment that the shared map was not readable with a phone due to the quirky layout of the old Google Maps interface… but when I have time maybe I’ll start playing with some of the new map-customization tools online…

I am fascinated by the messiness of the historical landscape before it was flattened and filled, with water confined to neatly linear paths. There are so many notations mapmakers used to depict the ways water manifested in the historical landscape. William Hammond Hall’s maps go beyond mere notation, into the realm of artistic representation. In contrast, USGS maps of contemporary Los Angeles use a limited and inflexible set of icons to depict water: blue lines for waterways (thin or thick, solid or dashed), and blue amoebas for lakes. Does the simplicity of these icons reflect what we’ve done to our surface water; or has what we’ve done to our surface water reflect our simplistic cultural idea about how a water body is supposed to look like and behave?

Let us know of other good resources you know, or any wish-list map projects to consider in the comments section…. there is another great map viewer in development that visualizes percolation, alluvial geology, water quality, and other topics, whose link I’ll post very soon…

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San Bernardino and Vicinity Irrigation Data, 1880, William Hammond Hall, David Rumsey Historical Map Collection


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 »

Joe’s Family Photoshoot on the L.A. River

February 18, 2015 § 1 Comment

Joe, Carrie, and Maeve at the L.A. River. Photo by Matt Grashaw

Joe, Carrie, and Maeve at the L.A. River. Photo by Matt Grashaw

Apologies for not posting anything here for a long time… then posting this puff-piece. I post daily over at Streetsblog L.A. these days, and just haven’t made the time to write a lot about the L.A. River, lately. Just to let folks know that my family and I are still around, and still enjoying the L.A. River, I am posting today with a couple of family photos taken on a family photoshoot yesterday. The photographer is Matt Grashaw who we highly recommend.

Joe and one-and-a-half year-old daughter Maeve.

Creek Freak Joe and one-and-a-half year-old daughter Maeve.

I think that the river looks pretty photogenic. The site is Bette Davis Picnic Area – the north end of Griffith Park, next to the recently-opened Glendale Narrows River Walk. See you down by the river.