Tier 1 Water Shortage for SW appears inevitable

[Jimmy Higgins]

The Southwest of the United States isn't very wet. But they've made due for decades with massive damming of rivers creating large lakes that hold up snow melt.

The last 20 years have been particularly tough. And the past year, not any better, dropping around 15 feet from a year ago. Lake Powell (named after a man named Lake) and Lake Mead (named after a different man named Lake) are at about 35% capacity, which isn't dripping low, but it is getting to a point where some reductions will be needed. These reductions (Tier 1) won't impact population centers, but somebody is gonna have to feel the sting.

If things continue for a few more years, Tier 2 will sting a bit in Arizona. Unfortunately, there isn't much of a solution. The amount of water needed for such large populations can be reduced, but not eliminated.

 

[steve_bank]

I read a govt reort in the 90s that predicted Southern California wuld b running out of water based on supply regardless of drought.

Agriculture wells are being fouled by salt water incursion.


The Colorado River is consumed.

r
The growth of the La area was never sustainable.

There have been attempts to buy public watersheds and privatize water.

In the 90s therewas an idea to dam up a valley in the Iaho panhandle and run water to Ca.

The question is what is a sustainable population?

 

[Loren Pechtel]

There's only one real answer: Desalinization plants. They're expensive, though.

I've hiked in areas that used to be part of Lake Mead--now there are decent sized trees there.

 

[barbos]

There's only one real answer: Desalinization plants. They're expensive, though.

I've hiked in areas that used to be part of Lake Mead--now there are decent sized trees there.

Most of water use in CA is agriculture. I am not sure Desalinization would make sense there.
If would be great if it does, though.

 

[DBT]

Most things having consequences, I wonder what the downside to large scale world wide desalinization may turn out to be.

 

[Treedbear]

Most things having consequences, I wonder what the downside to large scale world wide desalinization may turn out to be.

Rain.

 

[Jokodo]

Most things having consequences, I wonder what the downside to large scale world wide desalinization may turn out to be.

A small fraction of the lowered salt content of the oceans due to melting glaciers is compensated.

 

[DBT]

Most things having consequences, I wonder what the downside to large scale world wide desalinization may turn out to be.

A small fraction of the lowered salt content of the oceans due to melting glaciers is compensated.

I was thinking more along the lines of the local environment where tons of salt is being pumped into the ocean, which may impact on local ecosystems....presumably it takes a while to disperse even while it is constantly being pumped. Which may be an issue, I don't really know.

 

[Jokodo]

Most things having consequences, I wonder what the downside to large scale world wide desalinization may turn out to be.

A small fraction of the lowered salt content of the oceans due to melting glaciers is compensated.

I was thinking more along the lines of the local environment where tons of salt is being pumped into the ocean, which may impact on local ecosystems....presumably it takes a while to disperse even while it is constantly being pumped. Which may be an issue, I don't really know.

It doesn't take long to disperse. It's the ocean, it has currents and Eddie's.

 

[Valjean]

Most things having consequences, I wonder what the downside to large scale world wide desalinization may turn out to be.

It would be salt; discharged back into the sea, it would create massive, hypersaline dead zones.

"Eventual dispersion" doesn't matter. In most places dispersion would be slow: witness the eutrophic dead zones at the mouth of the Mississippi, or in some of the American Great Lakes -- and eutrophication is slow. Hypersalinity is fast. It can kill fish, coral or phytoplankton in minutes.

 

[Jokodo]

Most things having consequences, I wonder what the downside to large scale world wide desalinization may turn out to be.

It would be salt; discharged back into the sea, it would create massive, hypersaline dead zones.

"Eventual dispersion" doesn't matter. In most places dispersion would be slow: witness the eutrophic dead zones at the mouth of the Mississippi, or in some of the American Great Lakes -- and eutrophication is slow. Hypersalinity is fast. It can kill fish, coral or phytoplankton in minutes.

If you're supplying all of Eurasia with one plant, maybe. Otherwise, the seas have around 5% salt by mass, ranging from 1% in the Baltic Sea and 2-and-something min the Black Sea to the highest in the Red Sea. It's not like some trace element introduced in relatively small quantities that can lead to multiplication of it's abundance over a large mass of water.

 

[Valjean]

Elephant Butte ["byoot," not "butt"] lake, here in New Mexico, is only 11% full, and the Summer irrigation season is just beginning.
I'm picturing the Aral Sea, or the Salton Sea here in the US.

 

[Jokodo]

Elephant Butte ["byoot," not "butt"] lake, here in New Mexico, is only 11% full, and the Summer irrigation season is just beginning.
I'm picturing the Aral Sea, or the Salton Sea here in the US.

Yes, the Aral Sea was a hypersalination event. That's what you get when you loose 90%of your water, leading to a manyfold salinity increase.

However, all of humanity consuming water from desalination plants would barely produce a few billion tons of salt per day (if my math adds up it's almost exactly 1 billion by multiplying my local authorities' figure for household per capita consumption with the world population. Add a few billion for industry and agriculture and subtract a bit for the fact not everyone is as greedy as Western Europe. Sounds big, but compare it to the water volume, or the salt already dissolved, even of a small inland sea like the Ggulf of Mexico or the Mediterranean.

 

[Jokodo]

Also, overall salinity is actually dropping with melting glaciers permanently adding fresh water, while the water taken out doesn't stay out very long.

 

[Jokodo]

Actually, it's one billion tons of "water" per day from multiplying the equivalent of my city's per capita household consumption of 140l, not of salt. Salt is 50 millions tons or thereabouts, couple hundred million if you figure in agriculture and industry.

 

[Jimmy Higgins]

Also, overall salinity is actually dropping with melting glaciers permanently adding fresh water, while the water taken out doesn't stay out very long.

It does if used for agriculture.

 

[Jokodo]

Also, overall salinity is actually dropping with melting glaciers permanently adding fresh water, while the water taken out doesn't stay out very long.

It does if used for agriculture.

Nope, the carbs are broken down to water and co2 in the body, on the compost heap, in the fire.

 

[Jimmy Higgins]

I drink water and expel the water same day. Water for agriculture takes much longer than a day to go back into the water cycle.

 

[Jokodo]

I drink water and expel the water same day. Water for agriculture takes much longer than a day to go back into the water cycle.

Most of it dissipates or evaporates just as quickly. The share that's tied in plant matter or converted to organic molecules is minuscule, and that's back in the ocean in a matter of years too, unless it ends up in the Caspian or Aral Sea.

Melting glaciers are permanent, not not-next-day, but nor-next-millennium-either.

 

[barbos]

Just don't dump all brine in one place. Wikipedia says sea water must be treated with chemicals before processed in desalination plant and it could be a problem too. And 3 kWh per 1 m^3 of water, that's not that expensive