8 ms·

Deeper well drilling an unsustainable stopgap to groundwater depletion

136 points by jseliger 7y ago

th0ma5 7y ago
How good is measurement of water underground? I feel like we simply haven't drilled enough holes to know.
- _Microft 7y ago
  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#Oceanography,_hydrology,_and_ice_sheets https://en.wikipedia.org/wiki/GRACE_and_GRACE-FO#Oceanograph...
  - mturmon 7y ago
    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of groundwater withdrawals, because you don't know the relationship between height lost at the surface and volume withdrawn underneath.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.
- jubjubbird 7y ago
  In the U.S. it varies widely by state. The USGS has a map of "recent" groundwater levels: https://groundwaterwatch.usgs.gov/default.asp https://groundwaterwatch.usgs.gov/default.asp With some obvious large gaps. There are more collected by state agencies, consultants, etc. In most places there are probably more wells than you'd think. In addition to measuring gravity from space to monitor groundwater it can be measured at the land surface, with better spatial resolution and worse accuracy. A 1x10-8 m/s^2 change in gravity is 2.4 cm of groundwater! https://pubs.usgs.gov/fs/2018/3032/fs20183032.pdf https://pubs.usgs.gov/fs/2018/3032/fs20183032.pdf
notadoc 7y ago
"The Dust Bowl" by Ken Burns is a fantastic documentary. Hopefully we don't repeat that experience.
dahdum 7y ago
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-environment/2019/07/24/study-drilling-deeper-groundwater-wells-united-states-unsustainable/1797480001/ https://www.azcentral.com/story/news/local/arizona-environme... > 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 7y ago
  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)
phkahler 7y ago
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.
- slapshot 7y ago
  Yes. Spreading basins have become popular-ish in portions of California that have concentrated rainfall in the winter but high demand in the summer.[1] [1] https://www.newsdeeply.com/water/community/2018/06/21/the-two-biggest-challenges-to-groundwater-recharge-in-california https://www.newsdeeply.com/water/community/2018/06/21/the-tw...
- Fjolsvith 7y ago
  > 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.
- bluGill 7y ago
  Those are different farmers to a large extent. The farmers I know drain their fields and have no irrigation at all: I live in an area where there is typically more than enough rainfall, so it is better to endure low yield in drought years than to pay for the irrigation equipment that could help then.
- cwkoss 7y ago
  The amount of water soil can hold is fairly proportional with the amount of organic material. Blend woodchips, sawdust, compost into the top few feet of soil and it function like a moisture battery.
no_wizard 7y ago
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.
- adamwong246 7y ago
  Im interested to know the scale of a "water grid". Is there any idea how much water we'd need to move to satisfy all our demands with desalinated water? Also, what sort of energy is needed to raise all water up from sea-level?
  - dsfyu404ed 7y ago
    The average person uses 80-100gal per day. We'd need a grid that's about an order of magnitude larger than our current petroleum fuel distribution system (the average person probably uses less then 8-10gal of liquid petroleum fuel/day).
    - Scoundreller 7y ago
      Should be trivial to reduce that by 50% or more. But if water is artificially cheap, there will be no incentive. But will we learn to tax water and write everyone a cheque to cover the cost of a basic user? Just start with gray water re-use: nothing fancy: just a 55gal drum that collects the good gray water and discards anything looking spoiled. Pumps to toilet bowl with cheap pump.
hinkley 7y ago
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.
akeck 7y ago
Can (re)planting forests in a certain region (if possible) change the fresh water refresh rate?
ruffrey 7y ago
SGMA regulation in California attempts to address some of this.
stretchwithme 7y ago
The price of water has to reflect what it will cost to replace it, not just the cost of extracting it.
jdkee 7y ago
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-Information/Great-Lakes-Water-Levels/Water-Level-Forecast/Weekly-Great-Lakes-Water-Levels/ https://www.lre.usace.army.mil/Missions/Great-Lakes-Informat... 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.
29athrowaway 7y ago
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

136 points by jseliger 7y ago

th0ma5 7y ago

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

_Microft 7y ago
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#Oceanography,_hydrology,_and_ice_sheets https://en.wikipedia.org/wiki/GRACE_and_GRACE-FO#Oceanograph...
- mturmon 7y ago
  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.
jubjubbird 7y ago
In the U.S. it varies widely by state. The USGS has a map of "recent" groundwater levels: https://groundwaterwatch.usgs.gov/default.asp https://groundwaterwatch.usgs.gov/default.asp With some obvious large gaps. There are more collected by state agencies, consultants, etc. In most places there are probably more wells than you'd think. In addition to measuring gravity from space to monitor groundwater it can be measured at the land surface, with better spatial resolution and worse accuracy. A 1x10-8 m/s^2 change in gravity is 2.4 cm of groundwater! https://pubs.usgs.gov/fs/2018/3032/fs20183032.pdf https://pubs.usgs.gov/fs/2018/3032/fs20183032.pdf

notadoc 7y ago

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

dahdum 7y ago

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-environment/2019/07/24/study-drilling-deeper-groundwater-wells-united-states-unsustainable/1797480001/ https://www.azcentral.com/story/news/local/arizona-environme... > 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 7y ago
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)

phkahler 7y ago

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.

slapshot 7y ago
Yes. Spreading basins have become popular-ish in portions of California that have concentrated rainfall in the winter but high demand in the summer.[1] [1] https://www.newsdeeply.com/water/community/2018/06/21/the-two-biggest-challenges-to-groundwater-recharge-in-california https://www.newsdeeply.com/water/community/2018/06/21/the-tw...
Fjolsvith 7y ago
> 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.
bluGill 7y ago
Those are different farmers to a large extent. The farmers I know drain their fields and have no irrigation at all: I live in an area where there is typically more than enough rainfall, so it is better to endure low yield in drought years than to pay for the irrigation equipment that could help then.
cwkoss 7y ago
The amount of water soil can hold is fairly proportional with the amount of organic material. Blend woodchips, sawdust, compost into the top few feet of soil and it function like a moisture battery.

no_wizard 7y ago

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.

adamwong246 7y ago
Im interested to know the scale of a "water grid". Is there any idea how much water we'd need to move to satisfy all our demands with desalinated water? Also, what sort of energy is needed to raise all water up from sea-level?
- dsfyu404ed 7y ago
  The average person uses 80-100gal per day. We'd need a grid that's about an order of magnitude larger than our current petroleum fuel distribution system (the average person probably uses less then 8-10gal of liquid petroleum fuel/day).
  - Scoundreller 7y ago
    Should be trivial to reduce that by 50% or more. But if water is artificially cheap, there will be no incentive. But will we learn to tax water and write everyone a cheque to cover the cost of a basic user? Just start with gray water re-use: nothing fancy: just a 55gal drum that collects the good gray water and discards anything looking spoiled. Pumps to toilet bowl with cheap pump.

hinkley 7y ago

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.

akeck 7y ago

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

ruffrey 7y ago

SGMA regulation in California attempts to address some of this.

stretchwithme 7y ago

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

jdkee 7y ago

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

29athrowaway 7y ago

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