Warning: this is a long, subjective post, and might be a waste of your time. If you’re looking for real analysis, maybe just sit this one out.
Today is the 100th Anniversary of the dedication of the Los Angeles Aqueduct. Conceived of and designed by William Mulholland, the aqueduct (along with the southern transcontinental railroads and the ports) is one of the definitive pieces of LA infrastructure. The city simply would not exist the way it does today without the aqueduct.
So, in celebration of the aqueduct, let’s take a look at LA’s existing water sources, conservation efforts, and potential expansions.
Los Angeles Aqueduct (Owens Valley and Mono Basin)
The genius of the LA Aqueduct is its simplicity. Water from snowmelt in the East Sierra used to run into the Owens River and then into Owens Lake, an endorheic lake south of Lone Pine. Mulholland realized that the river could be diverted to flow, by gravity, to the San Fernando Valley using nothing but ditches, siphons, inverted siphons, and the like. Thus, the LA Aqueduct is one of LA’s best sources of water in terms of carbon footprint, since there is no need to pump the water to get it to the city. However, the diversion of the river resulted in the desiccation of Owens Lake.
Later, the city extended the system north to the Mono Basin using tunnels to get through the volcanic rocks that separate the basin from the Owens Valley, and constructed Lake Crowley for water storage and flood control. The diversion of the creeks feeding Mono Lake caused the water level in the lake to begin to fall, and it appeared that Mono Lake might suffer the same fate as Owens Lake. The formation of the Mono Lake Committee in 1978, resulting in lawsuits that were finally settled in 1994, spared Mono Lake from following in the footsteps of its larger, fresher neighbor to the south. As a result, today very little of LA’s water comes from the Mono Basin; at the time of this writing, the lake elevation is 6380.1’, still short of the target elevation of 6392’.
The city’s water sources in the Owens Valley have also come under pressure, due to demands for dust control from the Great Basin Air Quality Board (GBAQB). The dry lake bed is a significant source of dust, though certainly not the only one in a dry desert valley. Counterintuitively, dust is a problem because the water table remains close to the surface, which encourages salts and small particulate matter to migrate upwards to the surface, where they are picked up by the wind. GBAQB and LADWP have decided to address the dust problem by “rewatering” the lake bed, using a complex and expensive scheme of pumps and distributary equipment. This treatment is using almost half of the annual water volume that the aqueduct is capable of delivering.
I have a much dimmer view of the Owens Lake project than the Mono Lake controls. At the time the Mono Lake Committee was formed, the impacts to the lake ecosystem were just reaching a significant point. Much worse impacts to the brine shrimp and nesting birds were avoided by stabilizing and increasing the lake level. The city was able to adjust to the reduced flows with conservation efforts.
In contrast, Owens Lake has been dry for decades. Diverting water to the lake bed does not preserve lake ecosystems, because they are long gone. The salty environment is hard on pumping equipment, and rewatering is not the most cost-effective way to control dust on the lake bed. In fact, a cost-benefit analysis would likely show that almost any dust control measure does not make sense given that the primary beneficiaries are the 66 remaining residents of Keeler – a third of whom are over age 65, and 83% of whom are over age 45. Buying them out and focusing on dust control measures for times when the winds blow from the east (which is less common, prevailing winds are from the west) to mitigate dust generated by the lake in Lone Pine, Olancha, and Cartago (combined population about 2,500) would be much more logical.
The problem is that the Owens Lake project isn’t really about environmental benefits or controlling dust, it’s about settling old scores between the Owens Valley and Los Angeles. Residents of the valley are convinced that Los Angeles “stole” their water (I use scare quotes because the city bought the water rights). Grudges last for a long time, especially water grudges in the West, and depriving the city of water through legal mechanisms makes up for not being able to deprive the city of water by dynamiting the aqueduct. Meanwhile, the fate of other desert lakes in the West suggests that if the lake hadn’t been drained by Los Angeles, it would have been drained by agricultural interests.
Letting water and money needlessly vanish in the scorching Owens Valley sun is bad enough, but the Owens Lake project has significant negative effects on other parts of the system. It’s forced LADWP to increase water purchases from the Metropolitan Water District (MWD) via the Colorado River Aqueduct and the State Water Project (SWP) via the California Aqueduct. This results in using water sources that consume energy in being pumped over mountains on their way to Los Angeles, and creates needless conflict with other MWD and Colorado River users and with agricultural interests in the Central Valley.
The Owens Lake project needs to be completely reassessed. There is no point in wasting that water and throwing good money after bad. Remediation efforts should be based on achieving efficient results starting from present conditions, not wistful nostalgia and guilt for what happened in the past.
Colorado River Aqueduct
Mulholland was gone, ruined by the failure of the San Francisquito Canyon Dam in 1928, but the Colorado River Aqueduct was his conception too. Like the LA Aqueduct before, it caused some ill will with the locals in Arizona, who thought they should get the water. Phoenix and Tucson did get their water, eventually, with the completion of the Granite Reef Aqueduct, but in water law in the West, being first to the well counts for just about everything. Arizona’s and Nevada’s claims are now subservient to California’s, which means if the Bureau of Reclamation (USBR) is short of water, their deliveries will be cut first. Before rapid growth in places like Las Vegas and Phoenix, this wasn’t an issue, because Nevada and Arizona weren’t using their full allotments. But the day of reckoning is fast approaching; barring an above average snowpack this winter, cuts will be forthcoming in 2014 or 2015.
California’s share of water has been under pressure, too, from growth in places like San Diego. Unlike the LA Basin and IE, which at least have the LA Aqueduct and SWP, San Diego has no connection to water outside the MWD. Recently, this has led to the Imperial Valley selling some of its water to San Diego. Agricultural output can be maintained by switching to crops and varieties that use less water, and using more efficient irrigation systems.
Normally, that’s an all-around win, but in a twist of fate, agricultural runoff is the only thing maintaining the level of the Salton Sea. Troubled though it is, the Salton Sea is used by wildlife, and it can’t be allowed to dry up. If it were to dry, the pollution in the runoff that has accumulated would become airborne – making the problems at Owens Lake look small in comparison. The Salton Sea Authority was created to try to address this issue, but the money to execute their plan isn’t there yet. This might be a case where value capture is applicable – if you keep the sea from drying out, you really are adding value. Stabilizing the water level would also make lakefront property much more valuable; since the lake has no outlet, it is subject to considerable rises and falls in surface elevation as precipitation varies.
Really, the Colorado River is just about tapped out. Practically no users have surplus water. Las Vegas is so nervous about its sole water supply that it’s constructing a new intake from Lake Mead (lower than existing intakes, so that it will remain operable if lake levels drop) and building a pipeline hundreds of miles north into the Nevada desert to tap the meager water resources of the Basin and Range. There’s no water to be had here. California is lucky enough to have other sources. Arizona and Nevada will just have to adapt.
State Water Project
I have to say, as an engineer, the SWP is just waaay cool. Cruising up some world class highway engineering on the 5 through the Central Valley, looking out over endless farms and the gentle contours of the California Aqueduct and the Delta-Mendota Canal – that’s up there with kicking back on a whisper-soft high speed rail ride or hopping the world’s largest subway system, which didn’t even exist 20 years ago. Wait, sorry, engineering fantasies – what was I talking about?
The basic premise of the SWP is that water from the Feather River is stored at Oroville Dam, 450 miles north of LA. The water makes its way south via the Sacramento River, the Sacramento-San Joaquin Delta, and the California Aqueduct. Much of the water goes to irrigation in the Central Valley, but the aqueduct extends as far as Santa Barbara County (Coastal Branch), Castaic (West Branch), and Perris (East Branch). Water agencies as far away as Palm Springs participate in the SWP even though they have no direct connection (they swap MWD water for SWP water with agencies that connect to both). The SWP, along with the USBR’s Central Valley Project (CVP), is what makes the Central Valley an agricultural powerhouse.
Like many of California’s water supplies, SWP deliveries have come under pressure as a result of some dry winters, increased demand, and environmental concerns. In this case, the victim is the delta smelt, which lives in the Sacramento-San Joaquin Delta. During dry years, low water flows in the delta result in the SWP and CVP pumps on the south side of the delta creating unusual currents, which appear to be correlated with declines in fish populations. Again, I’m generally in favor of trying to preserve threatened ecosystems like these (as opposed to environmental vanity projects like rewatering the long-dry lower San Joaquin River).
When there’s insufficient water to meet all SWP demands, someone’s deliveries have to be cut, which often means less water is available for agriculture in the Central Valley. Some water can be stored in the San Luis Reservoir (the largest off-line reservoir in the US) and some can be supplemented by groundwater pumping. Long-term reliance on groundwater pumping risks drawing down the aquifer, though evidence suggests that unlike the Ogallala Aquifer, there is some recovery of Central Valley aquifers during wet years.
Agricultural interests in the Central Valley (and Imperial Valley, for that matter) seem to get little sympathy in the state’s more urban areas, maybe because environmentalists tend to view irrigated agriculture unfavorably. In my opinion, this is unfortunate: lower agricultural output means significant hardship for some of the state’s most vulnerable workers. Much of the state’s irrigated acreage (the Sacramento Valley, Friant-Kern Canal, eastern San Joaquin Valley, and Imperial Valley) is irrigated by gravity, requiring little energy to operate. The projects that do require pumping (SWP, Delta-Mendota Canal) aren’t that bad since the Central Valley is pretty flat – the big energy requirements on the SWP come in to get the water over the Tehachapi Mountains, which is for urban users in Southern California.
The ability to use reservoir and groundwater storage to smooth out wet and dry years is a major advantage of California agriculture, which can stand up to droughts that ruin crops in the Great Plains and eastern US. The moderate California climate means crops aren’t subject to damaging freezing temperatures like other places. Hopefully, we can manage our water resources to maintain the competitive advantages of California farming.
Local Groundwater and Conservation Efforts
I won’t say much about efforts to develop local groundwater resources and promote conservation in the LA area other than to say I’m in favor of it. These efforts ease pressure on outside sources, and increasing the number of sources provides some system resiliency, e.g. if the East Sierra is having a banner snow year, we could use groundwater storage to save up some water for dry years.
Channeling My Inner Mulholland
Ultimately, this would be a pretty boring post if all I did was recap our existing water sources with a little commentary thrown in, and at 2,100 words, maybe you’ve already tl;dr’d it. But if you’re still with me, here’s two other potential water sources we could tap.
I don’t know if the finances would pencil out, but they would add a couple resources that could be used to take pressure off of existing resources. The goal would be to develop the resources with a minimum environmental impact, and blend sources every year so that no one resource is overused. The obvious issue is that once you’ve paid to build the infrastructure, the temptation is there to max out everything, and then when a drought hits, you’re screwed. So hey, maybe we build these, call it SWP2, turn everything west of Lancaster into another Imperial Valley, and go down in a blaze of glory when a long drought hits like so many desert irrigation civilizations before us. I propose, you decide.
The East Fork of the Walker River is the logical last gasp in the East Sierra, just north of the Mono Basin. The headwater streams of the river pass pretty close to Conway Summit, which separates the Walker Basin from the Mono Basin. For the price of a short tunnel under the summit, you could build a diversion ditch to send some of that flow southeast to the Mono Basin. The West Fork of the Walker River is too far away, and the intervening terrain too mountainous, to make it practical to try to get anything out of that basin.
The terminus of the Walker River, Walker Lake, is not without its own issues due to local water diversions, and Nevada probably wouldn’t take too kindly to California trying to buy up all the water rights. This option would probably be a long shot, but maybe you could pitch it as a flood year only diversion. Precipitation in the Sierra can be irregular, and very heavy during El Nino years; the West Branch of the Walker River flooded badly in 1995, destroying parts of the 395. There could be a threshold snow water content for the snowpack that would allow some diversion during heavy snow years, and prevent flooding downstream on the Walker. The diversion ditch could connect into the Mono Basin Project pretty easily, thereby conveying the flow to Lake Crowley.
Delta Peripheral Canal and Northwestern California Rivers
The Delta Peripheral Canal was first contemplated as an actual canal during Jerry Brown’s first stint as governor; now, it’s been reconceived as a pair of bored tunnels to reduce environmental impacts to the delta, which makes canal a pretty significant misnomer. The point of the canal is to allow diversions from the Sacramento River to the SWP and CVP without creating the oddball delta currents that cause such issues for wildlife in the area. This would alleviate the need to cut water deliveries to Southern California.
But once you’ve got that conveyance, well, you might as well see what other water you could move with it, right? The clear prize would be the Eel River, where an enormous dam called Dos Rios was once proposed, which would have created the largest reservoir in California and sent water to the Central Valley via a tunnel. That contentious project was canceled by none other than conservative patron saint Ronald Reagan (so, if you’re keeping score, Democrat Pat Brown built the SWP, Democrat Jerry Brown is trying to build the Delta Peripheral Canal, and Republican Ronald Reagan screwed over big business in the Central Valley by canceling a dam. Just sayin’).
Again, if any sort of project were to take shape, I’d hope it could be done with much less environmental impact than Dos Rios. The Eel River flooded severely in 1964, so again, maybe a system could be set up that would only be activated during flooding events, though I don’t know how practical that would be. On the other hand, maybe you just build Dos Rios and call the lake the David Brower Reservoir, because you gotta have a sense of humor about these things.