California's Limited Freshwater Supply - Part I
(Originally posted January 28, 2017 on Blogger)
Is California's drought over?
According to the U.S. Drought Monitor, the drought is over in some 30 counties across northern California as of January 24, 2017, and are improving in counties in the southern half of the state.
At the time of this writing, much of Ventura, as well as portions of Los Angeles, Kern, and Santa Barbara counties remain under extreme drought conditions. The January 24, 2017 map you see above is the first map produced by the U.S. Drought Monitor in which 0% of the state is suffering from "D4-Exceptional Drought" conditions since January 2014. That's a heck of lot better than what the drought map looked like in late October 2014:
Well. There's our answer. Or at least the answer cited by most articles, blogs, videos, and TV interviews that I've read or seen.
Though, perhaps the best answer to the above question was answered by a hydroclimatologist and chief scientist at the Pacific Institute in Oakland; Peter Gleick. You can read his answer to this seemingly simple question here:
No doubt curtailed by space, Gleick was able to touch upon several important considerations when contemplating California's drought, and ends with a pertinent question we should all be asking ourselves (as individuals, as farmers, as government officials, and together as an interlinked society across the state); “Are we managing water in a sustainable manner for the long haul”?
But even that question requires some serious background, particularly if you live in California or eat any California agricultural exports; which means nearly everyone reading this. California is a global exporter of over 400 commodities. More than a third of the vegetables in markets across the United States come from California, and about two-thirds of the country's nuts and fruits come out of the Golden State. (Source: California Department of Food & Agriculture cdfa.ca.gov)
California--in the days before it was California--looked a lot different in the 18th and 19th centuries than it does today. Now I'll be careful here not to wear rose-colored glasses as I type; beautiful and pristine as California was, its southern deserts were as treacherous then as they are now. And though the great central valley was full of rich alluvium, much of this and the soils some of it turned into didn't entirely translate into a lush landscape until after rains.
Nonetheless, portions of the central valley were traversed by natural rivers fed by spring snow melt and occasional strong winter storms. Some events larger than others, causing rivers to flood and spread their rich alluvium guts across vast swaths of the central valley over time. But much of this alluvium sat upon the bedrock like potential energy sits on the edge of a slide; something needed to push it over the edge to put it to work. That push came sporadically as rain and other forms of precipitation. When it rained, I can only imagine how many flowers bloomed across the valley. To get an idea of how an arid landscape can be transformed by a wet winter, head out on the Carrizo Plain in the spring (assuming the rains keep coming through this winter). But it didn't always rain, and rivers were far from being ubiquitous.
Nevertheless, there were many areas that supported lush landscapes diverse in flora and fauna. There five rivers that drained out of the southern Sierra Nevadas into a large lake the Spaniards called, Laguna de Tache, and later American arrivals dubbed Tulare Lake. The lake had a surface area of some 1,780 sq. km and depths up to 40 feet or so (I'm basing the depth off today's dry lake bed depth, and old 19th-century records indicating its surface waters once reached 220 feet above mean sea level before overflowing its banks... so don't quote me).
At the time, Tulare Lake was the largest freshwater lake west of the Great Lakes, and a major source of food and water for the Tachi tribe. The Tachi fished its waters in reed boats and made their homes in lush landscape beyond the marshes that surrounded the lake. It must have been a slice of heaven on Earth to see. Even Mark Twain wrote about the lake after having visited its shores. He wrote about the birds, and how there were so many that when they took flight they'd blot out the Sun; a testament to just how healthy the natural environment was at that time.
If you're ever on Interstate 5 and passing by Kettleman City, then you'd be driving on the west bank of what was once Tulare Lake. Now as I said, I'm trying not to wear rosey glasses as I type this, but I'm purposely using Tulare Lake, or perhaps more aptly, using its non-existence as segue into a new chapter in California's water history; agriculture.
Perhaps it's most appropriate if I use the words printed in 1874 by the Government Printing Office out of Washington for this transition: "[Tulare Lake's] destruction by the late 1800s because of diking and water diversion for irrigation was one of the most dramatic signs of a major theme in the state's history: the rapid transformation of the wild California landscape into one dominated almost completely by human action."
(Source: Report of the Board of Commissioners on the Irrigation of the San Joaquin, Tulare, and Sacramento Valleys of the State of California - Courtesy of the Huntington Library)
As mentioned above, though the central valley was full of alluvium, it sat more or less as rich potential and little more to the would-be farmers that started trickling into the state around the time of the gold rush. What much of this alluvium lacked was a stable water supply. Even areas where rivers flowed naturally, wasn't always ag friendly; seasonal and rogue-storm-induced floods devastated some early attempts to reign in the land for agricultural use, and were sometimes tragically fatal.
In attempts to stabilize water supply, and stave off potential floods, farmers and engineers (some engineers were farmers too) began damming up streams and rivers such that they could control the flow below the dam and irrigate their fields year-round. This worked splendidly, until the dams were breached, or sedimentation simply walked the rivers over to new paths which more often than not went right through plowed fields. Energy goes from where it is to where it isn't in the path of least resistance.. this holds true for water just as much as it holds for electricity... or anything else that can equate to kinetic energy for that matter. Something perhaps the Army Corp of Engineers should consider with regard to the mighty Mississippi. But that's a topic already tackled long ago (prior to hurricane Katrina) by John McPhee, in his book, "The Control of Nature".
Bigger and bigger attempts to harness California's rivers (and the rivers that border the state) ensued, each with catastrophic, or near catastrophic results. Folks were starting to get wise to nature (or so you'd think), and realizing she was going to do what she was going to do "come hell or high water" as they used to say. Nature doing what it's going to do when it comes to rivers is an axiom. You can take that to the bank... and buy lots of flood insurance with it.
By the beginning of the 20th century folks were getting mighty bold in their attempts to tell nature's rivers where to go and when to go there. In 1900 the California Development Company (CDC) created what was then called the Alamo canal. It ran nearly 23 km from the Colorado River, through Mexico, and into the Imperial Valley. This engineering feat supplied the valley with a stable year-round flow of fresh water, irrigating over 100,000 acres of farmland by 1903. But, nature had enough of that shit, and in 1905 heavy floods blew out the canal's headworks and flowed out-of-control into the Salton Sink.... for two years straight. The CDC required the additional efforts of the Southern Pacific Railway (who had tracks in the valley), and the federal government to shore up the breach and return the Colorado river to its natural path into the Gulf of California... but not before a 72 km long lake had formed, remnants of which slosh around in today's Salton Sea.
With the Alamo canal gone and the waters it once delivered with it, farmers in the Imperial Valley were left with nothing. But with California's population exploding by just over 60% between 1900 and 1910 (1,485,053 to 2,377,549 according to the U.S. Census Bureau), it was apparent that water would need to be returned to the state from the Colorado somehow, if this growth was to be sustained.
So in 1922, the Colorado River Compact was agreed upon by seven states; (Arizona initially refused to sign, resolved only through compromise in 1944, as I'll get to soon.) The Compact divided the drainage basin of the Colorado and its tributaries into an upper and lower basin. The upper basin drainage would be used to supply Colorado, Utah, Wyoming, New Mexico, and a small portion to Arizona, and the lower basin drainage would supply Arizona, Nevada, and California. It was determined that each basin would supply its states with 7.5 million acre-feet per year (1 acre-foot = 325,851 gallons).
The Colorado River allocations as outlined in the Compact assured California would get 4.4 million acre-feet per year (26.7% share of the flow)... the largest share of seven states. Colorado received the second largest share of water; 3.88 million acre-feet/yr. Nevada had the smallest share, only 300,000 acre-feet/yr (1.8%), but they accepted this amount because they were confident in their ground water supplies, and wanted a larger share of the hydroelectric power generated from dams along the Colorado. Mexico was allocated 1.5 million acre-feet/yr (9.1% share agreed to in 1944).
Arizona didn't initially sign the Compact because of concerns California would take the lion's share of water from the lower basin allotment. Ha HAAAA!! They were on to us! It wasn't until 1944 when it reached a compromise to receive a "firm" 2.8 million acre-feet. "Firm" in the sense that it was only firm in non-drought years. In years of drought, California's 4.4 million acre-feet were to be prioritized.
Unfortunately, a drought in California generally equates to a drought in Arizona, and the way I see it, droughts tend not to stop at state lines when they occur. So one can imagine the conundrum this puts Arizona in. The Pacific Southwest Water Plan of the mid-20th century sought to ensure Arizona received its share of water by diverting water to the Colorado river basin from other river basins. The plan was the predecessor to the Central Arizona Project. But that's Arizona, and I ought not get off on a tangent there. This is already going to be a long and complicated write up.
I didn't list all the state allotments above because I want to focus on California. With that said, if we add up all the allotments for each state involved in the Compact, the sum comes to 16.5 million acre-feet. At the time, it was believed this was an amount the river could easily supply year after year, for it was less than the river's calculated total output. Or so it was believed.
The draftees of the Colorado River Compact based their total flow number on ~30 years of flow rate data. A 30-year average is the norm... for calculating norms. That data showed the Colorado River discharged an average of 17.5 million acre-feet per year; 1 million acre-feet more than allotted all seven states. In theory, this meant there was a million acre-feet of buffer, and by extension, meant a million acre-feet of water would make it all the way to the Gulf, where a fragile ecosystem (once) exist(ed).
However, total flow expectations didn't pan out as calculated or forecast. As it turns out, tree ring records taken since the Compact was signed indicate that the 3 decades from which data was taken were among the wettest in centuries. Unfortunately, the more accurate average total flow was/is closer to 13.5 million acre-feet, for a deficit of 3 million acre-feet rather than a surplus of one million. This miscalculation is exacerbated by droughts of course; of which the southwest has been suffering from in recent years, has suffered from in the distant past, and will likely suffer from time and time again in the future.
With less-than-expected supply, states scrambled to compensate with dams and resulting reservoirs in order to help ensure stable supply year-round by keeping water in storage. Though, this isn't the only function of dams. In fact, they serve 3 major functions:
Storage for a not-so-rainy day
Hydroelectric power production
Some of the dams completed in the early 20th century were behemoths. In 1935 the U.S. Bureau of Reclamation (USBR) completed the Hoover dam, which created Lake Mead. This lake (reservoir) is capable of holding up to a 2-year supply (based on current demands), in case of drought years.
In the same year the Hoover dam was authorized, a new version of the Alamo canal was approved. This time the canal was named the All American Canal, because unlike its ill-fated predecessor, this new canal would remain entirely within the United States border. Thus water returned to the Imperial Valley. What was once one of the driest parts of California, became one of its most fertile. Today the canal is responsible for irrigating over 630,000 acres of farmland and supplying water to 9 cities for industrial, public, and domestic use.
More dams followed; the Imperial and Parker dams in '38, creating the Imperial Reservoir and Lake Havasu respectively. The latter supporting a hydroelectric plant with an annual output of nearly 457 gigawatt hours. With each dam came more hydroelectric power, more flood control assurance, and more water in storage for drought years. Of course, dams come at great environmental cost as I'll get to later.
As it stood, more water was needed, not just for agriculture, but for urban use as well. San Diego, established back in the 18th century, was a burgeoning city by the 1940s. It's demands for freshwater grew with its population and industry. In response to this, a system of aqueducts was completed in 1947, known as the San Diego Aqueduct Branch. It supplied the city with about 90% of its water, and continues to do so to this day. A precarious position to be in; much like having all your eggs in one basket so to speak. In an earthquake prone state, having 90% of a major city's water supplied by a single source (the Colorado River) is potentially catastrophic.
Well aware of this, the San Diego County Water Authority added seawater desalination to its 'portfolio' of freshwater income. Operations at the desal plant began in December 2015 and now provide the city with 56,000 acre-feet/yr on a 30-year contract. According to the Authority, this amount will meet 8% of the city's projected 2020 demands. Having worked in seawater desalination on contract for companies from here to Livermore, I can say that desalination is an unavoidably relatively inefficient and costly way to obtain freshwater. But then again, what choice does a city the size (in population) of San Diego have at this point?
At this point, flood-preventing dams cross rivers throughout the lower basin. Reservoirs dot the landscape ensure months to years continued supply in times of drought... though lose about 15% of their supply to evaporation. The Colorado's flow has been divvied up so thoroughly that just a trickle if anything makes it to the ocean. And hydroelectric plants, so far, adequately power agriculture and urban centers. But despite all this, demand for freshwater continues to grow; drought or no drought. The human machine is a juggernaut, and nature must be controlled.
Juggernaut or not (that rhymed!), there simply is no way the Colorado River is going to supply southern California with an adequate supply of freshwater to keep industry, agriculture, and people alive (or afloat if you prefer). Fortunately, the Colorado isn't the only source of freshwater for southern California. In the words of Yoda, "There is another".
Obviously I haven't answered the questions posed:
"Are we still in a drought?"
“Are we managing water in a sustainable manner for the long haul?"
But I feel these questions can't be adequately answered yet, as I've only just begun scratching the surface of a very complicated history, and system of laws and realities on the ground that must serve as a backdrop to climate. Answers to those questions ought to be extrapolated from a full(er) suite of information than perhaps most are willing to absorb. Yourselves not included! :)
I will do my best to publish Part II to this by Monday (January 30th). In the second part, I plan to outline the water systems stemming from the Sacramento-San Joaquin River Delta, and reservoirs (particularly Oroville) and streams leading into it. I'll discuss issues of subsidence of Delta islands, salt water intrusion issues, the current and future states of levee systems, the incredibly-complicated water rights that will boggle your minds! All this will require brief histories of the State Water Project, Army Corp of Engineers, and Central Valley Project. I'll delve into the major reservoir capacities and what they mean, touch upon salmon migration issues, future dam-heightening plans and their many implications... I'll get into urban population growth, gently tread about the sensitive topic of farm subsidies and crop types. I discuss micro and macro climate schemes and "forecasts". I'll even discuss the risk a large earthquake poses should it occur in a certain area. A risk that, it seems, the entire state is ignoring. The next blog will be a doozy, but hopefully educational and illicit critical thought.
I hope this at least served as a decent warm up for what is to come...
Please consider continuing on to Part II by clicking the link below: