
Wildfire threatening the power grid that supplies San Francisco - mpchlets
http://www.npr.org/blogs/thetwo-way/2013/08/24/215099616/san-francisco-under-emergency-as-fire-threatens-power-water
======
001sky
For anyone wondering what the relationship between wildfires in Yosemite and
San Francisco proper, its worth a small comment. California's Sierra Nevada
range is a couple hours east of SF. These mountains include the highest points
in the continental US. Trapping most of the water from the east-west jet
stream. The sierras hold massive amounts of high-quality water, which runs out
of the non-porous terrain of the high-alpine regions. The sierras are
something of a geological monolith, not unlike a giant bathub [1]. SF taps
into this water source at a dam on the West; LA taps into it on the East (LA
acqueduct). This fire is threatening the a region about an hour or so north of
Yosemite Valley, and west of Tuolome Meadows, where some critical infrastucure
resides.[2]

[1]
[https://upload.wikimedia.org/wikipedia/en/a/a2/Sierra_nevada...](https://upload.wikimedia.org/wikipedia/en/a/a2/Sierra_nevada_schematic.svg)

[2]
[https://en.wikipedia.org/wiki/O%27Shaughnessy_Dam_%28Califor...](https://en.wikipedia.org/wiki/O%27Shaughnessy_Dam_%28California%29)

~~~
hkmurakami
I remember talking to one of the rangers at Yosemite, near one of the natural
lakes that eventually supply water to SF. I remember him saying that he tells
visitors who go answer nature's call at the lake to think twice, since they're
going to be drinking this very water soon.

~~~
fnordfnordfnord
What did he say about drinking fish shit? And the effluent of every other
critter in the park?

~~~
pyre
I think that it has more to do with the idea that humans moving through that
area would do much more damage (than the local animal population) if they were
not discouraged in some way.

~~~
fnordfnordfnord
Rangers should discourage people from fouling the area, but the comparison
made by the Ranger is nonsensical on a number of levels. Anyone who heard it
might disregard it after recognizing how silly an argument it was.

------
agwa
This article is vague (and overly alarmist); other sources I have read
indicate that the threat is to SF's municipal power company, which provides
power primarily to municipal buildings (including, most notably, SFO!). The
vast majority of people in SF and the Bay Area get their power from PG&E,
which has power plants in many more places than just Yosemite.

More info:
[http://www.sfwater.org/index.aspx?page=391](http://www.sfwater.org/index.aspx?page=391)

~~~
tomsaffell
Yes, the NPR article is alarmist, verging on irresponsible.

A few facts, with sources:

\- The water coming out of Hetchy Hetchy is still well within the 'usable'
range [1]

\- The total loss of power is 293 MW (Holm and Kirkwood), which is a tiny
percentage of the power generated in CA [1,2]

\- The SF PUC is already dealing with the loss of those 293 MW: _San Francisco
is making up the difference in power generation by accessing power in an
existing power bank and purchasing power on the open market._ [1]

\- PG&E is reporting no problems in their network (at 10:20 PT) [3]

Keep calm, carry on. Perhaps take it as an opportunity to turn of the lights
you're not using, like you should every day ;)

1\.
[http://www.sfwater.org/index.aspx?page=711](http://www.sfwater.org/index.aspx?page=711)
(see chart) 2\.
[http://en.wikipedia.org/wiki/List_of_power_stations_in_Calif...](http://en.wikipedia.org/wiki/List_of_power_stations_in_California)
3\.
[http://www.pge.com/en/myhome/customerservice/energystatus/gr...](http://www.pge.com/en/myhome/customerservice/energystatus/gridstatus/index.page)

~~~
ChuckMcM
Its only alarmist if it doesn't get worse :-) Seriously though, alarmist or
not, its _serious_. This fire is growing and not contained. There exists a
non-zero chance of it creating a serious impact into the available clean water
supply. And this is to a county not exactly known for its fiscal
responsibility or ability to respond well to crisis.

~~~
pyre
But at least San Francisco has maintained it's charm! That's what's really
important.

------
Stratoscope
Hetch Hetchy water doesn't just go to San Francisco. Two-thirds of it goes to
other cities and towns on the Peninsula, the South Bay, and in Alameda County.
In particular, many cities that the Hetch Hetchy Aqueduct runs through get
some of the water, because voter approval in those cities was part of the
campaign to get the project built.

For example, 74% of Mountain View's water comes from Hetch Hetchy. (They get
87% of their water from the SF Public Utilities Commission, and 85% of that
comes from Hetch Hetchy.) [1]

Daly City, San Bruno, and South San Francisco currently get 67% of their water
from SFPUC and the rest from local aquifers, with a project in the works to
increase the SFPUC portion to 100%. [2]

Palo Alto, Menlo Park, and other towns also rely on it, although I don't know
the percentages.

Many have seen the pipeline that crosses the Bay between the Dumbarton Bridge
and the old railroad bridge.

There are also a number places in the Peninsula and South Bay where you can
see parts of the Hetch Hetchy Aqueduct, either the pipes themselves or the
above-ground access hatches where the pipe is underground. These are white
structures, often circular.

For example if you walk or run the Dish Trail at Stanford, you can see a
number of these next to the northernmost part of the trail. This is part of
the southern branch of the Aqueduct, which doesn't cross the Bay but cuts
south through Milpitas, Sunnyvale, and Mountain View.

Several places where you see a residential street that is divided with a very
wide grassy or dirt median, that's the Aqueduct: Sharon Heights Drive and Ivy
Drive in Menlo Park are examples.

Along Edgewood Road near 280 there are a number of pipeline sections where it
alternates between above-ground bridges and underground sections through those
hills. The pipeline then parallels the Cordilleras Trail in the Pulgas Ridge
Open Space Preserve where you can see some of the access structures.

On the other side of 280 on Cañada Road there is the famous Pulgas Water
Temple [4], where you can really get a sense of how much water flows through
the Aqueduct.

For the obsessively curious like me, several years ago I traced the path of
the southern branch of the Aqueduct and made a KML file marking some of the
visible structures. [3] Someone else had made a similar file for the northern
branch but I don't know where to find that now.

[1]:
[http://www.mountainview.gov/city_hall/public_works/water_con...](http://www.mountainview.gov/city_hall/public_works/water_conservation/supply.asp)

[2]: [http://www.sfexaminer.com/sanfrancisco/three-peninsula-
citie...](http://www.sfexaminer.com/sanfrancisco/three-peninsula-cities-may-
soon-switch-from-groundwater-to-hetch-hetchy-water/Content?oid=2349754)

[3]: [http://mg.to/earth/hetchy.kml](http://mg.to/earth/hetchy.kml)

[4]:
[http://en.wikipedia.org/wiki/Pulgas_Water_Temple](http://en.wikipedia.org/wiki/Pulgas_Water_Temple)

~~~
Stratoscope
I forgot to add... Here's a Street View from Ivy Drive in Menlo Park that
happened to be taken during a pipeline addition/reconstruction. They set out
the pipe sections in the street median before digging to lay them in place.
These are some big pipes!

[https://www.google.com/maps?ll=37.47579%2C-122.1629239999999...](https://www.google.com/maps?ll=37.47579%2C-122.16292399999999&cbp=%2C298.35%2C%2C2%2C13.769997&layer=c&panoid=IoXzvywNxSsrEU4sCUCujg&spn=0.18000000000000152%2C0.30000000000000676&output=classic&cbll=37.47579%2C-122.162924)

(You may need to zoom out; I couldn't figure out how to save a URL with the
correct zoom level.)

------
fnordfnordfnord
Looks like a good case for decentralization of the power grid; a good
application for a small modular LFTR[1] (or similar) power units. As a bonus,
you won't need to spoil the scenery with HV transmission lines anymore.

[1] Liquid Fluoride Thorium Reactor

~~~
NIL8
Interesting concept. Of course, the first thing that comes to mind is how to
protect these units from the bad guys.

~~~
Tcepsa
If you mean "protect these units from bad guys so they don't threaten our
electrical system," that's kind of the point of having a decentralized system
of smaller reactors: if one or two get sabotaged, others in the system can
easily pick up the slack.

If you mean "protect these units from bad guys so they don't steal the thorium
and weaponize it," that's one of the great things about thorium reactors:
thorium and its byproducts are very hard to weaponize. [1]

[1]
[https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reacto...](https://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor#Safety)

~~~
kintamanimatt
What about the health impact following a release of materials?

~~~
tehwalrus
Molten salt thorium reactors are "continuous reprocessing" ones, which means
they burn all the (active) waste they create for more energy.

Solid thorium reactors mix Th with the existing waste piles of Plutonium
sitting in cooling pools and burn that up for us[1].

There's no waste materials to release from either of these reactors.

[1] [http://www.extremetech.com/extreme/160131-thorium-nuclear-
re...](http://www.extremetech.com/extreme/160131-thorium-nuclear-reactor-
trial-begins-could-provide-cleaner-safer-almost-waste-free-energy)

~~~
hga
Waste != Materials.

These reactors by definition have a fair amount of very "hot" materials; it
hardly matters if none of them are declared "waste" if they'll still kill you
in a few minutes of direct exposure.

~~~
tehwalrus
...

molten salt reactors (the kind in the comment at the top of this thread) are
at atmospheric pressure, and are designed with a drain plug which isolates the
(very hot) materials from the neutron source, after which they cool down
happily on their own in a separate but similarly shielded compartment.

release of materials is one of the most unlikely outcomes _ever_.

~~~
hga
You really can't imagine a release of materials outcome in the context of
active sabotage?

(Which is relevant in the context of massive distributed ones; current nuclear
power systems mitigate this by being few in number such that they can be well
guarded.)

~~~
tehwalrus
since you can't weaponise the mixture, and it's just stupidly hot and
dangerous for a while and then inert, I can't see why anyone would _try_ to
sabotage one. (apart from terrorists just out to cause mayhem, but that
argument also works for cars, roads, planes, train stations, etc right?)

------
joering2
The system continues to be broken. Hundreds of millions going into building
lethal drones to deploy to Afganistan/ME; some major american cities are on a
brink of releasing police surveillance drones en masse (its constitution/law-
questionable now), and yet we do not have drones to fight fire.

I am pretty sure there are lot of challenges within the project, but I can
envision drones working together to connect each other and transport water to
sprinkle it when needed without humans being endangered. I mean, if we
achieved this [1], why not go further?

[1]
[http://www.youtube.com/watch?v=oDyfGM35ekc](http://www.youtube.com/watch?v=oDyfGM35ekc)

~~~
hga
Errrm, this translates into a "making _large_ drones" problem. Which has a
whole set of additional problems, e.g. what are you going to say to the
survivors of a devastated neighborhood when a big drone with lots of water
crashes into it?

I'm not saying its insurmountable, just that it's way beyond the current
levels of both drone technology and acceptance.

~~~
joering2
The biggest problem fighting fires are lethal to humans high temperatures and
lack of easy access to places affected. Those two problems would be irrelevant
to properly designed drones that can easy maneuver and are built from
temperature-resistant materials.

Instead of huge drone carrying water (we already have planes to do that now),
I was envision a network of connected drones that "pass by" the water as they
hover in the line all the way from water pool to fireplace. The video attached
previously shows you group of drones perfectly communicating with each other.

I never said it was easy to develop, but I have to disagree its something "way
beyound the current levels" of technology. Further, the cost to design,
develop and implement would be pennies comparing to an average damage of mid-
size fire. Not the mention about life-loss.

~~~
001sky
You either need large payloads or large numbers, but Thousands of drones
flying around would likely lead to accidents. Accidents woudl likely lead to
new fires, considering most of these things are happening in areas that are
tinderboxes with significant aggrivating factors (high winds, exposure, etc).

The strategy for containing these fires is typically fuel deprivation, rather
than "flame extinguishment" which is so difficult if not impossible for the
above reasons. The guys that jump out of planes to fight backcountry fires,
for example, are armed with axes and saws. Absent something like a star-wars
(AT-AT) its not clear a direct frontal confrontation is pyhsically feasible,
even from the air, for many fires.

------
nether
Isn't there a Google interview question for this?

------
tomjen3
Damn. The powers that be better do something about this fast. SF is about one
of the last places in the US to develop new things.

Heck just a temporary prolonged outage of Google alone would have huge
negative consequences for the US (not to mention the world). Amazon AWS US
west is in Northeren California. I wonder how big the negative effect will be
on just how many companies?

~~~
argumentum
The "City" of San Francisco (though it does contain a big chunk of the tech
industry and houses many of it's employees) is not the whole "Silicon Valley".

Google, Facebook, LinkedIn, Y-Combinator, Stanford, Yahoo, etc are all located
in the South Bay and (may or may not be, the article doesn't specify) affected
by the fires.

~~~
jcl
Don't know about the power grid, but about half the water supply in Mountain
View comes from local wells, so it would not be _as_ affected as SF, but part
of the rest comes from Hetch Hetchy, so there could still be problems. Not
sure if local resources get reallocated in emergencies.

[http://www.valleywater.org/Services/CleanReliableWater.aspx](http://www.valleywater.org/Services/CleanReliableWater.aspx)

~~~
davidw
Most people think hackers don't have good personal hygiene skills anyway, so I
think those companies could skate for a little bit if push came to shove...

