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Photo Source: the Los Angeles Department of Water and Power, Public Domain No one would have thought that this "great" canal brought water and disaster.

In 1898, Frederick Eaton was elected as the 33rd mayor of Los Angeles, but he faced a big problem: where to get enough water supply for Los Angeles, which has experienced rapid development and population explosion?

In order to be elected mayor of Los Angeles, one of Eaton's political slogans is to introduce new water sources for the city. Now, in order to make good on his promise, Eaton has set his sights on Lake Owens Lake, which is more than 200 kilometers away.

In theory, Lake Owens, 200 kilometers away, does not belong to the city of Los Angeles, and Eaton has no right to draw water from there, but distance does not stop his ambitions. In order to obtain water rights, Eaton began to buy farms and pastures around Owens Lake in a private name, and then transferred the water rights to Los Angeles, "deceiving" 90% of the water rights in the Owens Valley.

With the right to use water, Eaton also wants citizens to pay for the canal. Next, the Los Angeles City Water and Power Bureau (Los Angeles Department of Water and Power,LADWP), headed by a good friend of Eaton, began secretly draining water from the Los Angeles reservoir into the Pacific Ocean, while promoting water shortages caused by drought. Under such an offensive, the city of Los Angeles successfully sold $24.5 million in canal bonds, which was used to build a pipeline from Lake Owens to Los Angeles.

The canal, which is 375km long and consumed 15000 tons of steel and 2678 tons of explosives, was finally put into use on November 5, 1913. On the day the gate opened, tens of thousands of Los Angeles residents came to the San Fernando Valley (San Fernando Valley) to celebrate the arrival of a new water source. Eaton generously announced to the media and the public: "right here, take it." (There it is, take it)

But no one would have thought that this "great" canal brought water and disaster.

Los Angeles Canal Plan (Photo: the City of Los Angeles, Public Domain) Dead Dust before the canal was renovated, Lake Owens, covering an area of 280sq km and a depth of 7-15m, attracted a large number of waterbirds and maintained the ecology of the Owens Valley. However, as the water continued to flow to Los Angeles, 13 years after the canal was built, the 800,000-year-old lake completely dried up in 1926.

The dry lake brought unexpected problems. The prevailing winter wind blows through the dry and exposed lake bed, sweeping up a large amount of sediment at the bottom of the lake. The clay originally deposited at the bottom of the lake, carrying heavy metals such as arsenic and cadmium, turned into fine dust fluttering in the wind.

Today, we already know that PM10 and PM2.5 account for more than 60% of this dust, sometimes up to 90%. These tiny particles can go deep into the lungs and even enter the bloodstream, causing many health problems, including asthma, lung cancer, cardiovascular disease and so on.

At that time, however, local residents did not know what the dust would bring to them. For residents of Keeler, a small town on the east bank of Lake Owens, all they know is that sandstorms have been "standard" every winter since 1926, accompanied by burns in the eyes, throat and ears and an inexplicable increase in lung cancer. And this scene lasted for more than 60 years.

On February 3, 1988, Keeler's air monitoring station measured record concentrations of air pollutants during the storm: at that time, the US Environmental Protection Agency (EPA) safety limit for air dust (dust) was 150 micrograms per cubic meter, while more than 600 micrograms per cubic meter would be considered a "major health hazard" (the current EPA level I standard for PM10, that is, 150 micrograms per cubic meter to protect public health. The first-level standard for PM2.5 is 12 micrograms per cubic meter). But on that Friday, the air dust data measured in Keeler was 1860 micrograms per cubic meter-more than 10 times the EPA safety standard and more than 3 times the major hazard standard.

According to a 1989 Los Angeles Times report, Jack Jack Riley, a retired employee of LADWP, lives in Keeler. Every time he sees a white "cloud" rising from Lake Owens, he knows the town will be covered with dust: "the dust is like flour. I have to stay indoors, lock the window and connect the oxygen tank."

There are only 90 people left in a town that once boomed because of railways and mining. "the dust has reduced the number of people in the town," said Mike Ushman, a local painter. "I have recently learned that four people have died of lung cancer or other lung diseases, and two of my tenants are going to move out as soon as the storm is over."

To make matters worse, Keeler is not the only town affected. For more than six decades after 1926, this dry lake bed has been the largest single source of PM10 pollution in the United States. More than 80,000 tons of PM10 particles rise from Lake Owens each year, according to a report. Tiny particles of air pollution can form aerosols in the atmosphere and spread over long distances. According to a report issued at the time by the Great Basin Joint Air pollution Control area (Great Basin Unified Air Pollution Control District), dust from Lake Owens could spread at least 250km away, affecting an estimated 40,000 people.

The Great Salt Lake in 2019 (photo: Dicklyon / wikipedia) has been 109 years since the construction of the Los Angeles canal, but the recent situation in the Great Salt Lake in Utah is increasingly reminiscent of the incident in Owens Lake. The Great Salt Lake is located in the arid western United States, but the snow that falls in the mountains melts into rivers that supply water to nearby towns and farmland and eventually flow into the Great Salt Lake.

In the past, the water of the Great Salt Lake has been in a delicate balance. In summer, evaporation can cause the lake to drop by about half a meter. When the snow melts the following spring, the lake will rise back to normal.

However, with the increasing demand for water, more snow-capped mountain meltwater is led away to irrigate farmland before reaching the Great Salt Lake. The high temperatures brought about by climate change have intensified the evaporation of water in summer and greatly increased the water demand of grasslands and crops. Last summer, the water level of the Great Salt Lake reached its lowest level on record, with the area shrinking by 2/3.

This has led scientists to worry about whether the unique ecology of the Great Salt Lake can be maintained: it is one of the few areas with microbial mats, where dense algae and bacteria form layers of reef-like structures (if they form fossils, it's called stromatolite).

As the water level of the Great Salt Lake drops, the salinity of the lake is becoming higher and higher. In this case, the microbial pad will also occur similar to the coral "whitening" phenomenon. The water level of the Great Salt Lake may still rise back next spring, but ecologists estimate that the recovery rate of microbes at this salinity may become very slow.

More worryingly, if the Great Salt Lake dries up, it will also cause air pollution problems similar to those of Lake Owens-unlike Lake Owens, which is relatively sparsely populated, next to the Great Salt Lake is Salt Lake City, Utah. It is home to 75% of Utah's population.

After being blocked by a railway dam, the amount of water in the northern part of the Great Salt Lake decreased, the salinity increased significantly, and halophilic algae and bacteria turned the lake red (Photo: NASA). After more than 60 years of drying up, the air pollution of Lake Owens has finally ushered in the hope of solving the problem.

In 1990, the then US President George W. Bush signed an amendment to the Clean Air Act, which listed land use and industry as pollution sources. nine years later, the EPA asked LADWP to implement dust prevention measures in the areas with the most serious problems, or face huge fines. Under such pressure, LADWP chose the seemingly most convenient solution-filling the lake back.

LADWP has spent more than $2 billion since the 1990s, but has not been able to restore Lake Owens. The vast surface of the lake is no longer seen, only shallow puddles are distributed among the scattered basins.

But fortunately, the lake bed covered by shallow water did effectively control the dust, and the city of Los Angeles avoided fines. This method is then summarized as shallow irrigation (shallow flooding), which covers the sand-blowing area by diverting water, and a series of berms are built to form the sand control area. This not only prevents the valuable water from flowing to areas that do not need to be covered by running water, but also recycles the water downstream.

Another unexpected joy is the return of wild animals. In 2010, researchers counted nearly 40,000 native and migratory birds in Lake Owens in a single day, including the rare western snow plover (Charadrius nivosus). In 2011, that number was close to 60,000, reaching 115,000 in 2013, including a large number of brown-breasted snipes (Recurvirostra americana).

Perhaps for humans and animals living near Lake Owens today, they are "lucky" to get an acceptable result after all.

But next time, will mankind have such good luck?

Reference link:

Https://www.nature.com/articles/d41586-018-07353-6

Https://www.latimes.com/archives/la-xpm-1989-04-02-mn-1380-story.html

Https://eol.jsc.nasa.gov/Collections/EarthObservatory/articles/AlgaeinGreatSaltLake.htm

Https://geochange.er.usgs.gov/sw/impacts/geology/owens/

Https://web.archive.org/web/20160304095007/http://www.gbuapcd.org/Air%20Quality%20Plans/2008SIPfinal/EIR/Volume%20II/G_OWENS%20LAKE%20SLERA%20PDF%20COMPLETE.pdf

This article comes from the official account of Wechat: global Science (ID:huanqiukexue). Article: 27, revision: Clefable

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