4 ms·

OP's point is that you have two glasses now, which are empty. Another two to make four and you'll have four empty glasses. You need to address the reason why t

OP's point is that you have two glasses now, which are empty. Another two to make four and you'll have four empty glasses. You need to address the reason why they're empty. You said you know the system well, so do you mind explaining?

lovecg 5y ago
They’re empty now, but presumably they would not have been pre-drought, delaying the point when the current shortage begins.
- wpietri 5y ago
  You can't presume that. You have to show it. In particular, you have to show the new reservoir would capture water that would last long enough to matter. It has been years since some of the large reservoirs were close to full. Where specifically do you believe new reservoirs should be built? And why do you do believe that they will capture water that keep from evaporating long enough to make a difference during the next drought cycle?
- Someone 5y ago
  I don’t think it is a given that, this time, there will be a post-drought that fills the current reservoirs. If so, if extra reservoirs were built years ago, they would have been useful exactly once. On top of that, that ‘useful’ could have been very limited. For example, shortening a half year drought by a week would not be worth anything if it just meant crops would die a week later. You have to do some serious modeling on expected rainfall, the costs of reservoirs and water usage to figure out whether additional reservoirs are worth the investment.
eplanit 5y ago
So 100% of reservoir loss is due to evaporation? In the analogy, filling the glasses before EBMUD turns the water off is like filling a reservoir during (even brief) rainy seasons.
- avianlyric 5y ago
  Think you would a better leg to stand on if California’s reservoirs actually filled up during the year. As it stands California’s reservoirs never seem to fill completely anymore. Adding more reservoirs won’t help store extra water if it simply isn’t falling from the sky.
  - jdavis703 5y ago
    The Oroville dam was so full it was at risk of overtopping just a few years ago. https://en.m.wikipedia.org/wiki/Oroville_Dam https://en.m.wikipedia.org/wiki/Oroville_Dam
- pixl97 5y ago
  More reservoirs doesn't make more water in the first place. This is about how much that falls from the sky in the first place. You should not stop all the water from reaching the ocean in the first place, bad things happen when you do that. We are reaching the point where we just have enough water to keep the rivers flowing so we don't kill all the wildlife that exists in them, we're not adding significant amounts of water to storage.
- defterGoose 5y ago
  If you distributed the total available water to more reservoirs then the loss rate from evaporation would actually go up due to an increased ratio of surface area to volume. Simple math, really.

lovecg 5y ago

They’re empty now, but presumably they would not have been pre-drought, delaying the point when the current shortage begins.

wpietri 5y ago
You can't presume that. You have to show it. In particular, you have to show the new reservoir would capture water that would last long enough to matter. It has been years since some of the large reservoirs were close to full. Where specifically do you believe new reservoirs should be built? And why do you do believe that they will capture water that keep from evaporating long enough to make a difference during the next drought cycle?
Someone 5y ago
I don’t think it is a given that, this time, there will be a post-drought that fills the current reservoirs. If so, if extra reservoirs were built years ago, they would have been useful exactly once. On top of that, that ‘useful’ could have been very limited. For example, shortening a half year drought by a week would not be worth anything if it just meant crops would die a week later. You have to do some serious modeling on expected rainfall, the costs of reservoirs and water usage to figure out whether additional reservoirs are worth the investment.

eplanit 5y ago

So 100% of reservoir loss is due to evaporation? In the analogy, filling the glasses before EBMUD turns the water off is like filling a reservoir during (even brief) rainy seasons.

avianlyric 5y ago
Think you would a better leg to stand on if California’s reservoirs actually filled up during the year. As it stands California’s reservoirs never seem to fill completely anymore. Adding more reservoirs won’t help store extra water if it simply isn’t falling from the sky.
- jdavis703 5y ago
  The Oroville dam was so full it was at risk of overtopping just a few years ago. https://en.m.wikipedia.org/wiki/Oroville_Dam https://en.m.wikipedia.org/wiki/Oroville_Dam
pixl97 5y ago
More reservoirs doesn't make more water in the first place. This is about how much that falls from the sky in the first place. You should not stop all the water from reaching the ocean in the first place, bad things happen when you do that. We are reaching the point where we just have enough water to keep the rivers flowing so we don't kill all the wildlife that exists in them, we're not adding significant amounts of water to storage.
defterGoose 5y ago
If you distributed the total available water to more reservoirs then the loss rate from evaporation would actually go up due to an increased ratio of surface area to volume. Simple math, really.