Environment & Energy

Warpy

(114,547 posts)

30. The reservoirs contain fresh water

Sun Apr 5, 2015, 05:58 PM

Apr 2015

You're asking if we can pump salt water in and once it's through the sluice gates into the irrigation channels, the salt will be somehow filtered out?

No, it doesn't work that way. The salt is ionized within the sea water. The only ways to get rid of it are energy intensive, either by distilling the water or by using semipermeable membranes and pumps.

While nuclear powered desalinization units for small amounts of people on submarines are cost effective, trying to support a city the size of LA through desalinization plants is not, nor is it cost effective to use it in agriculture.

There are prototype setups that condense humidity along the coastline into potable water, but those wouldn't be particularly useful in semi arid conditions inland.

California's best bet in the short term is strict conservation. Longer term, they'll have to join those conservation measures with population reduction and a change in agricultural irrigation methods from spray or trench irrigation to subsoil drip irrigation. Living in California is not going to be nearly as convenient as it was 20 years ago.

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DU: Beware the Water Desalination Movement and it's Lies. [View all] NYC_SKP Apr 2015 OP

There's a big push for that in California, while our good, clean water is sucked up by Nestle arcane1 Apr 2015 #1

Precisely. Some bottled water comes directly from municiple sources; tap water. NYC_SKP Apr 2015 #3

Lets take California as a start. there are 38.4 million residents who live there. CentralMass Apr 2015 #2

The era of free ground water is over, I say OVER ... MindMover Apr 2015 #5

And companies like Nestle (not to mention agriculture) use the majority of it. arcane1 Apr 2015 #7

The LA Times article was very misleading, scientifically inaccurate. NYC_SKP Apr 2015 #8

You know I do think that's what he is suggesting. I missed it until you pointed it out. nm rhett o rick Apr 2015 #38

WATER is not next, it is now ... MindMover Apr 2015 #4

Desal is a scheme to preserve our wasteful way of life. New tech or not, it's a loser. NYC_SKP Apr 2015 #10

"Nature gave us a predictable amount of water to use" MindMover Apr 2015 #22

"Loading Order" in electric utilities would be instructive here. NYC_SKP Apr 2015 #25

Post removed Post removed Apr 2015 #27

I'm not sure what your issue is with me and my statements. NYC_SKP Apr 2015 #35

Freshwater and water are two different substances to you? pbmus Apr 2015 #73

They technically, environmentally, and regulatorily are different substances, yes. NYC_SKP Apr 2015 #75

I have read thru all of mindmovers posts and he/she never ever used pbmus Apr 2015 #77

. NYC_SKP Apr 2015 #79

Metaphorically speaking the question was pbmus Apr 2015 #85

NYC_SKP is absolutely correct. bananas Apr 2015 #46

"and now you will cause oversalinization." pbmus Apr 2015 #67

It just means too much salt. bananas Apr 2015 #86

"if you put hundreds or thousands of them along the coast, you will disrupt the entire coast ecolog" pbmus Apr 2015 #88

"or" not "of" bananas Apr 2015 #89

"Building desalination plants is the Right Wing Corporatist approach to solving the problem." Ghost in the Machine Apr 2015 #43

You do know that desalination won't put a dent in sea levels, right? NYC_SKP Apr 2015 #47

Thank you for your clarification, my friend.... Ghost in the Machine Apr 2015 #54

So I went to do the math again. Humans consume +/- 3,000 km^3 per year worldwide... NYC_SKP Apr 2015 #57

SORRY. There are no "new technologies that are coming online" that will provide more water. NYC_SKP Apr 2015 #42

I believe I have heard this argument used with oil and how pbmus Apr 2015 #68

That line of thinking brought us horizontal drilling, fracking, and oil shale and tar sands... NYC_SKP Apr 2015 #69

So you do agree that your arguments are the same . pbmus Apr 2015 #72

I liken "advancements" in water exploitation to those used in fossil fuel extraction, yes I do. NYC_SKP Apr 2015 #76

If you are likening water resources to other commodities pbmus Apr 2015 #80

We (humans) have been using or as you say screwing the planet pbmus Apr 2015 #74

Yeah, we might have another 2.8 million years to go without changing our ways. NYC_SKP Apr 2015 #78

So your entire point is that we must change. pbmus Apr 2015 #83

Is there any beneficial use for the salts that are removed during the desalination process? tularetom Apr 2015 #6

They dump it back into the ocean at higher concentrations. NYC_SKP Apr 2015 #9

That's really dumb when they could bag it, dry it Warpy Apr 2015 #26

Thank you God for Wiki pbmus Apr 2015 #71

Couldnt they sell the salt Travis_0004 Apr 2015 #12

Desalenizaton uses three liters of salt water to make one liter of freshwater. Agnosticsherbet Apr 2015 #18

California has been WET! ... 4139 Apr 2015 #11

Ahistorically wet; long dry periods are "normal", some of them lasting centuries. Spider Jerusalem Apr 2015 #23

but maybe you can answer me this- mopinko Apr 2015 #13

Filling a salt wate lake would kill local vegatation nad indigenous animals that need the fresh Agnosticsherbet Apr 2015 #15

i meant aquifers. mopinko Apr 2015 #33

The salt would remain with the water. There are, in fact, Agnosticsherbet Apr 2015 #50

Under the right circumstances, this might yield some water, not sure if it's economical. NYC_SKP Apr 2015 #16

want. mopinko Apr 2015 #17

What about creating large reservoir beds closer to the ocean Chemisse Apr 2015 #29

I think solar distillation would be more cost effective and less impactive. NYC_SKP Apr 2015 #32

I love this idea!! Chemisse Apr 2015 #45

The reservoirs contain fresh water Warpy Apr 2015 #30

i meant to say aquifers. mopinko Apr 2015 #31

No, it doesn't work that way, either Warpy Apr 2015 #36

It might work in the short term but eventually all that salt that was filtered out would tularetom Apr 2015 #70

California is not getting enough water from rain or snow. Agnosticsherbet Apr 2015 #14

We simply use too much. No need for desal plants, better to invest in greywater systems. NYC_SKP Apr 2015 #19

No, we are not getting enough water. This is a symptom of climate change. Agnosticsherbet Apr 2015 #21

I don't understand the concept of areas of the country that get too much water. rhett o rick Apr 2015 #39

We've had flooding back east. What I suggest is we set up a naton wide system Agnosticsherbet Apr 2015 #49

My initial impression is that you are suggesting that some areas steal water from other areas. rhett o rick Apr 2015 #52

That seems to be the suggestion being made. It was a failure then and would be again. NYC_SKP Apr 2015 #61

Yes I do agree, "we use too much stuff". rhett o rick Apr 2015 #66

We are using too much, too fast, and simply need to use less. NYC_SKP Apr 2015 #41

Agriculture uses too much, that's the biggest issue Spider Jerusalem Apr 2015 #24

Alternatively: water demand is too high, the amount of water is the natural amount. NYC_SKP Apr 2015 #20

The amount of watner needed is based on the states populaton. Agnosticsherbet Apr 2015 #51

The residential water needed is actually state population X gallons/person/day. NYC_SKP Apr 2015 #55

So we should cease farming and put several million people out of work, Agnosticsherbet Apr 2015 #59

Allow me to continue to educate you, my good friend: NYC_SKP Apr 2015 #60

Due go long term changes in weather patterns (climate change) Agnosticsherbet Apr 2015 #62

Please look into the energy demand and environmental impacts of desalination. NYC_SKP Apr 2015 #63

hugelkultur mopinko Apr 2015 #64

Inertia. Systems at rest tend to remain at rest (agribusiness) NYC_SKP Apr 2015 #65

tell me about it. mopinko Apr 2015 #81

Yeah, right? You're under a freakin' microscope there! NYC_SKP Apr 2015 #82

hey, beating city hall was on my bucket list. mopinko Apr 2015 #87

I wonder if you could make floating passive solar evaporators. Erich Bloodaxe BSN Apr 2015 #28

Black bottoms, clear tops maybe, like giant "Water Cones": NYC_SKP Apr 2015 #34

Sorta what I was thinking, but simply open at the top Erich Bloodaxe BSN Apr 2015 #37

Better if it's closed at the top, need to maintain high temp, humidity , closed system. NYC_SKP Apr 2015 #44

What if the black layer was permeable, in a loose weave? Erich Bloodaxe BSN Apr 2015 #48

This could be a great improvement, provided the high temps can be reached and maintained. NYC_SKP Apr 2015 #53

Do some mirroring, not just transparency, so it functions a bit more like a solar oven? Erich Bloodaxe BSN Apr 2015 #56

I'd keep it closed, mirrors might work well, and flotatation would be build in. NYC_SKP Apr 2015 #58

Important subject. Thanks for posting. nm rhett o rick Apr 2015 #40

Thanks for the thread. roody Apr 2015 #84