
Deeper well drilling an unsustainable stopgap to groundwater depletion - jseliger
https://www.nature.com/articles/s41893-019-0325-z
======
no_wizard
When I was a young kid, I spoke with an agricultural engineer once that came
to our school and he gave a talk about his career and what he did and the
things he was finding (this was in say 2007/2008)

The part I remember the most and what intrigued me is when he was talking
about ground water supply. He said that it would be unwise to keep digging
into ground water supply for fresh water, for agriculture or otherwise, and
what we really needed desperately was a nation-wide grid (I live in the USA,
for reference) of pipes similar to how oil gets pumped for hundreds or in some
cases thousands of miles, to supply desalinated water from the coasts to every
part of america and to use properly use desalinated water to re-hydrate
American rivers and wells, otherwise we will find ourselves in a situation of
hastening a cycle of pumping ground water at an unfeasible pace, which to me
is suggested in this article.

Seems relevant now, and I imagine the long term sustainability of such a thing
would be much higher (and less depleting).

Looks like that guy was right. I wonder how many people have been sounding
this alarm over the last decade.

~~~
mr_overalls
Large swaths of the country currently receive sufficient rainfall to meet
agricultural, industrial, and municipal needs. Desalinating and pumping water
from the coasts as a complete replacement solution is madness.

Any realistic solution to water scarcity will be a multi-pronged approach:
improvements in water infrastructure, groundwater recharge, pollution control,
water conservation, rainwater harvesting, and technology-driven gains in
purification/distribution efficiency.

~~~
jdavis703
How can we make this argument when rivers like the Colorado are barely a
trickle by the time they reach the ocean? Even arid areas that seem fertile
like the Southwest and the Central Valley are only fertile because we're
diverting and pumping water unsustainably.

~~~
niftich
Because most of the US does not have this problem. The Colorado River basin
does, but it's worth noting that California's allocation is very high relative
to the portion of the drainage basin within the state, and most of the state's
allocation (>88%) is pumped out of the basin.

Top users of California's allocation of Colorado River water are [1]:

\- the Irrigation Districts of the Imperial Valley (~61%) and its northwest
extension the Coachella Valley (~8%);

\- the Metropolitan Water District of Southern California (~20%) [2];

\- the Palo Verde Irrigation District (~8%). The Palo Verde Irrigation
District is inside the Colorado River basin.

[1]
[https://www.usbr.gov/lc/region/g4000/4200Rpts/DecreeRpt/2018...](https://www.usbr.gov/lc/region/g4000/4200Rpts/DecreeRpt/2018/2018.pdf)
[2]
[http://www.mwdh2o.com/AboutYourWater/Sources%20Of%20Supply/P...](http://www.mwdh2o.com/AboutYourWater/Sources%20Of%20Supply/Pages/default.aspx)

~~~
bradknowles
At the very least, you'd think that California could make much more use of
desalination, and greatly reduce the amount of damage they do to the CRB.

------
phkahler
Farmers engineer their fields to drain excess rain water. That is part of the
reason major floods happen along rivers more often than they used to. But then
they need to pump water out of the ground more often to water crops. Is there
a way to get the rain water to go into the ground instead? That would help
with both problems.

~~~
Fjolsvith
> Farmers engineer their fields to drain excess rain water. That is part of
> the reason major floods happen along rivers more often than they used to.

Not everywhere. Western Kansas has water conservation districts with terraces
plowed into fields. One of the reasons that reservoirs and ponds were low for
so long.

This year, they are all full, due to the massive rainfall we've had.

------
jdkee
Too much water.

The Great Lakes are at record high levels this year, causing flooding and
sandy beaches on the lake shores to simply disappear under water.

[https://www.lre.usace.army.mil/Missions/Great-Lakes-
Informat...](https://www.lre.usace.army.mil/Missions/Great-Lakes-
Information/Great-Lakes-Water-Levels/Water-Level-Forecast/Weekly-Great-Lakes-
Water-Levels/)

The St. Lawrence river discharges approx. 16,800 m^3 a second of freshwater
from the Great Lakes. However re-diverting the water to areas outside the
watershed are would require an international compact between the U.S. and
Canada and the various sovereign Indian territories to allow for it to happen.

------
dahdum
I can't access the study, but this news report says it doesn't examine the
causes behind this. For instance, it's way cheaper to drill deeper first then
going back and doing it, you generally get cleaner water, and better flow.

[https://www.azcentral.com/story/news/local/arizona-
environme...](https://www.azcentral.com/story/news/local/arizona-
environment/2019/07/24/study-drilling-deeper-groundwater-wells-united-states-
unsustainable/1797480001/)

> The study was published Monday in the journal Nature Sustainability. The
> authors didn’t examine causes behind the drilling of deeper wells but said
> factors can include declining water levels, improving pump technologies,
> different permit requirements for wells that tap deep aquifers and poor
> water quality in shallow aquifers.

~~~
hinkley
Saw this elsewhere, and someone pointed out that choliform bacterial
contamination, where it exists, is worse at the top of the aquifer, so people
drill deeper to get to the cleaner water.

We should really take a look at how that stuff and nitrates from fertilizer
are getting down there in the first place. Either our model of aquifers is
wrong in very important ways or existing wells are getting backwash problems
(eg, ground water following the outside of the bore down, or negative pressure
when the pump is off pulling water in through defects in the pipes)

------
notadoc
"The Dust Bowl" by Ken Burns is a fantastic documentary. Hopefully we don't
repeat that experience.

------
hinkley
I tried to do the math one time of figuring out the volume of water we've
pulled out of all of the world's aquifers, and how that translates to sea
level rise (water ends up underground or in the ocean eventually).

I'd like to see someone with better geography skills repeat that experiment.

------
29athrowaway
Watch this documentary:

"Pumped Dry: The Global Crisis of Vanishing Groundwater"
[https://www.youtube.com/watch?v=RjsThobgq7Q](https://www.youtube.com/watch?v=RjsThobgq7Q)

------
stretchwithme
The price of water has to reflect what it will cost to replace it, not just
the cost of extracting it.

------
th0ma5
How good is measurement of water underground? I feel like we simply haven't
drilled enough holes to know.

~~~
_Microft
You don't have to drill holes to monitor ground water. Here's an example for
remote measurements:

[https://en.wikipedia.org/wiki/GRACE_and_GRACE-
FO#Oceanograph...](https://en.wikipedia.org/wiki/GRACE_and_GRACE-
FO#Oceanography,_hydrology,_and_ice_sheets)

~~~
mturmon
Yes: Gravimetric measurements from GRACE have been a breakthrough. The press
release referenced within your wiki citation is well worth reading in this
context:

[https://www.jpl.nasa.gov/news/news.php?feature=4626](https://www.jpl.nasa.gov/news/news.php?feature=4626)

Besides _in situ_ wells, other helpful measurement techniques are InSAR
(interferometric SAR) and post-processed GPS. Both let you measure surface
subsidence to better than 1cm accuracy over broad areas, mostly due to
groundwater withdrawals. This subsidence (which is in the multi-meter range in
parts of CA, [https://www.usgs.gov/centers/ca-water-
ls](https://www.usgs.gov/centers/ca-water-ls)) is of concern in and of itself,
due to disruption of infrastructure like highways and pipelines caused by
subsidence.

But, subsidence is indirect as a measurement of groundwater withdrawals,
because you don't know the relationship between height lost at the surface and
volume withdrawn underneath. This depends on a compaction parameter which is
very hard to know.

Property owners can stymie the use of wells as a groundwater monitoring tool,
because it is often not in their direct interest to supply information about
local groundwater depletion. For this and other reasons, it's rather hard to
use well data, even in well-instrumented areas like California.

------
akeck
Can (re)planting forests in a certain region (if possible) change the fresh
water refresh rate?

------
ruffrey
SGMA regulation in California attempts to address some of this.

