Draining California • Hacker News Board

Re: Draining California

#61

Post by huherto » Sat, Sep 20, 2014, 6:41 PM UTC

blahedo wrote: post #37

bryanlarsen wrote: post #32

We live in Ottawa, Canada. Last year we had a very dry summer, so the city sent out notices asking people to please water their lawns regularly. The Ottawa River is a major river, Ottawa is the only major user of its water, and doesn't really make a dent in the flow, especially since we put our wastewater back into the Ottawa (after treatment, mostly). They had no concern about water security, but they did have a con…

The Great Lakes region is a whole other thing. In fifty or a hundred years, it's cities like Milwaukee, Chicago, Cleveland, Ottawa, and even Detroit that will be booming---because they will still have bountiful access to clean freshwater.

This is why I think Detroit is in a better position than most people think. Just give the city back to nature and it will flourish again.

Re: Draining California

#62

Post by ghshephard » Sat, Sep 20, 2014, 7:21 PM UTC

tanzam75 wrote: post #54

refurb wrote: post #43

Earlier quoted context omitted.

Really? I find acre-inches pretty intuitive. Maybe convert to hectare-centimeters?

That's non-metric thinking. In the metric system, you could simply use the cubic meter. A hectare is 10000 square meters. A centimeter is 0.01 meters. Thus, if 1 centimeter of rain falls on a 1 hectare field, then that's simply 100 cubic meters of water. The nice thing about this is that you can easily compare quantities from different contexts. A cubic meter is a cubic meter, whether the water came from a pipe or fr…

What unit do farmers in europe/civilized world pay for their water in? Is it cubic-meters or cm-hectares?

Re: Draining California

#63

Post by Shivetya » Sat, Sep 20, 2014, 7:34 PM UTC

snomad wrote: post #34

Many people will often say agricultural uses 80% of the water. This is not the whole picture. "Nature provides about 200 million acre-feet of precipitation to California in average years. Of this total, 65% is lost through evaporation and transpiration by trees and other plants. The remaining 35% stays in the state’s system as runoff. More than 30% of this runoff flows out to the Pacific Ocean or other salt sinks. Th…

it is self inflicted by the US Government. Why? Because they over subsidized the water being sold there, so the cost of the water was so low that wasteful practices and water needy crops became the norm because it was more than affordable, it was nearly a give away.

Re: Draining California

#64

Post by hughdbrown » Sat, Sep 20, 2014, 7:35 PM UTC

ghshephard wrote: post #55

hughdbrown wrote: post #53

Earlier quoted context omitted.

Maybe American farmers should trade in their acres of farmland for hectares. There could be a government program to exchange one for the other. But really -- read the comments and check out the number of times these units are mentioned and converted: - "200 million acre-feet of precipitation to California in average years" - "No doubt when water hits $100/barrel..." - "1 Barrel = 42 Gallons. It costs $0.75/cubic mete…

No argument from me on any of that, totally makes sense. And thanks for the correction of 70,000 m^3 -> 70,000 * 1000 m^3 for Crystal Spring Reservoir. (I'll admit to having to have Soulver up just to have this conversation - Metric system would make it way, way easier.)

So when you hear 70 000 cubic meters, try to visualize it: 1.4m deep by 50m long by 25m (1750 cubic meters) is about an Olympic swimming pool. So we would be talking about a reservoir made up of 40 Olympic swimming pools, and then we'd say, "Hey, that seems pretty small for a reservoir."

Maybe when wikipedia says that the reservoir is 57,910 acre-feet you have a sense of what that would look like, but I have absolutely no intuition on that, even though I know that an acre is 43 560 square feet and that there are 640 acres to a square mile.

[1] https://en.wikipedia.org/wiki/Crystal_Springs_Reservoir

Re: Draining California

#65

Post by seanflyon » Sat, Sep 20, 2014, 8:30 PM UTC

ghshephard wrote: post #29

seanflyon wrote: post #24

Earlier quoted context omitted.

Water is fungible.

But expensive to transport relative to its value.

Expensive to transport in some cases but not others. In the scenario I was responding to it is quite cheap to transport water form the mountains past the farms to the cities because water flows down hill. Water that is not used in farming is available for use in the cities.

Re: Draining California

#66

Post by [deleted] » Sat, Sep 20, 2014, 9:52 PM UTC

sparkman55 wrote: post #12

It's not clear from the (beautiful!) article, but 4 times as much water goes to agricultural use than to municipal use in California. People won't die of thirst in California, but crops aren't doing as well. In particular, orchards spread through much of California's central valley. These are perennial plants (trees or vines), living decades in some cases. If you've mortgaged the farm to plant acres of fruit or nut t…

[deleted]

Re: Draining California

#67

Post by ilaksh » Sat, Sep 20, 2014, 10:03 PM UTC

Strategies like desalination (see San Diego's new huge desalination project), hydroponics/aquaponics and (ultra)local production can make these problems more manageable.

Instead of giant agricultural fields that are open to evaporation, hydroponic or aquaponics inside of greenhouses could vastly reduce water usage.

Instead of huge farms or corporations producing food tens or hundreds of miles away from where it is eaten, community/neighborhood or even household food production could be an alternative. This would be more efficient and save on energy and other costs needed for transporting and retailing food.

These things will probably become more economically viable and popular as solar becomes a consumer-level reality. As in, people are buying solar kits at Walmart or Home Depot regularly. The prices are almost already there.

Pretty sure that a lot of this is related to network effects and trends. The neighborhood urban hydroponic farming thing becomes more economically viable as it becomes more popular, simply because more people are cooperating (via the market) in order to make that more convenient.

Of course, there is a limit to how much food we can produce locally. Right now, even if we converted every Target into an urban farm, and every home and apartment used advanced technology to pull in solar energy efficiently and dedicated a full 1/3 of its space to hydroponic or aquaponic produce, we might only be able to supply a fraction of our food needs that way. What fraction that would be, 10%, 20% or 50%, not sure.

But I feel like that more local production is going to be more efficient and robust in the end, and more and more popular as we start to distribute production technologies more evenly.

Re: Draining California

#68

Post by [deleted] » Sat, Sep 20, 2014, 10:33 PM UTC

[deleted] wrote: post #66

sparkman55 wrote: post #12

It's not clear from the (beautiful!) article, but 4 times as much water goes to agricultural use than to municipal use in California. People won't die of thirst in California, but crops aren't doing as well. In particular, orchards spread through much of California's central valley. These are perennial plants (trees or vines), living decades in some cases. If you've mortgaged the farm to plant acres of fruit or nut t…

[deleted]

[deleted]

Re: Draining California

#69

Post by maxxxxx » Sat, Sep 20, 2014, 10:56 PM UTC

sytelus wrote: post #6

Are there any actual water shortage for normal folks in residential places? For example, do you still have 24 hr water available in your apartments? Is water from tap usually drinkable? These drought stuff is pretty scary but I haven't yet heard if normal (non agriculture) folks getting hurt yet.

In my neighborhood (LA) the lawn sprinklers still run every night and flood the streets.

Re: Draining California

#70

Post by mrbabbage » Sat, Sep 20, 2014, 11:48 PM UTC

tanzam75 wrote: post #54

refurb wrote: post #43

Earlier quoted context omitted.

Really? I find acre-inches pretty intuitive. Maybe convert to hectare-centimeters?

That's non-metric thinking. In the metric system, you could simply use the cubic meter. A hectare is 10000 square meters. A centimeter is 0.01 meters. Thus, if 1 centimeter of rain falls on a 1 hectare field, then that's simply 100 cubic meters of water. The nice thing about this is that you can easily compare quantities from different contexts. A cubic meter is a cubic meter, whether the water came from a pipe or fr…

> It's not just water. Look at HVAC. In the US, natural gas is billed in therms, and electricity is billed in kilowatt-hours. In metric countries, both electricity and natural gas are specified in kilowatt-hours.

It's funny you use that example, because kWh are silly, unnecessarily convoluted units themselves :-) the "proper" unit for this dimension is the joule, and 1 kWh = 3.6 MJ (1000 J/s ∙ 1 hr ∙ 3600 s / hr ∙ 1 MJ / 1e6 J).

There actually is, however, some value in having different units for methane vs electricity, since you have to run methane through a suboptimal furnace to harness its energy. Granted, modern gas-powered furnaces are usually more than 90% efficient, but there's still some loss. And since each customer has a different furnace with a different eta, it's usually not useful to directly compare natural gas tariffs vs electricity tariffs even if you do have a cogen unit.