Great column on ground water today.

I really enjoyed the parts on the underground rivers and their formations.

I was happy to see Cecil address the using up of a limited resource as far as some ancient aquifers.

This is a huge problem is some areas. I know that in Australia, there is a major water problem and there is currently a fight between some of the natives, the scrub ranchers and some hideously wasteful desert resorts.

So many communities around the world never think about the future.


Nitpick: “Karst” is not a type of rock (as Cecil implied), but rather a collection of geomorphological features which tend to form where limestone or related rocks are chemically weathered.

An excellent column, aside from a couple of geological gaffs. The depletion of underground aquifers is a (perhaps the) major environmental calamity that nobody seems to talk about; certainly Al Gore and his ilk, while railing on about the dangers of global climate change (which, while detrimental in effect, may or may not be experienced on the scope predicted and can be dealt with regardless) have almost completely disregarded both the infrastructure and the ground structure effects of aquifer depletion. Without water to drink, to processes food, to provide sanitation, and to support the ground, we sink and die.


I’m not sure I’ve heard about this. Do tell. I’ve never heard of “desert resorts” being a significant water waste problem. Certainly the thousands of bores drilled to water cattle and left to free flow are hugely wasteful. I’ve never heard that it is the indigenous population that are fighting the issue from one side or the other particularly.

If all this water is being removed the from water table it’s gotta go somewhere.
The volumes Cecil mentions are pretty significant.

Assuming the water isn’t hanging around on the surface, I wonder what effect it’s having on sea levels? And if thats a factor in rising sea levels blamed on global warming? Are we talking volumes high enough to do that?

In a word, no. However, subsidence can cause low lying areas to sink further, making them more prone to flooding in general. The areas most at risk for flooding due to rising average sea levels are typically at or often below sea level to begin with. These areas are typically coastal and lack a significant potable water ground table anyway.


This was what we were attempting to convey, perhaps unsuccessfully, with the construction “hollowed-out limestone or other soluble bedrock.”

The aquifers in Manhattan all completely dried out a century ago. Now we have to plunder our water from upstate.

Sorry, I cannot help you out. It was in a Scientific America Magazine from half a year ago or so. I do not know the month and I am choosing to be lazy and not find it. If you wish to dismiss it, please do so.


I’m sure I heard of people tapping into the aquifer under Manhattan which exempts them from water restrictions rules when implemented.

Got it! I see now that “karst” is meant to modify the entire phrase “typically hollowed-out limestone or other soluble bedrock,” and is not meant to be a second example of “…enough rock” (the first example being “limestone”). By its position at the end of the same comma-delimited phrase as “limestone,” and by its being immediately after the word “bedrock,” I took it to mean the latter.

Still, a reply from Ed himself…I am not worthy!

I think this concept refers mainly to things like golf courses and other temperate zone landscaping that sucks up a lot of water and is incongruent with desert environments.

…such as greater Los Angeles?

Actually on that subject, I believe California suffers more water waste from the rice farms and cattle farms in the deserts than from LA.

It might be worth looking up. California had some interesting water rules that I think are still in effect. It made it cost effective to grow rice in the desert.


Rice farms in WHAT California desert? :confused: :confused:

They grow rice in the San Juaquin/Sacramento Rivers delta. Not in the desert. Now, they DO grow alfalfa in the desert. And, technically, a whole lot more in what is nominally desert by definition, though not desert in actual appearance.

It looks like the ‘Rice in the Desert’ is an exaggeration on my part, but there does appear to be a large amount of water being poured into the rice growing in California. The federal water subsidy did allow for massive agriculture projects and the rice alone consumes as much as LA does.

The web resources to back this up is not readily available. Here are two pertinent links related to the agricultural use of water vs. city use.

The Greening of the California Desert

Maybe **Cecil ** would be willing to give us the **Straight Dope ** on this issue, both historical and current.


Some folks, including novelist Carl Hiassen, have asserted that the continuous population growth of the state of Florida will (soon or eventually) overcome the aquifer’s capacity to provide water. How realistic is that assertion?

I don’t know the details, but it seems quite possible. Despite the rainfall, Florida’s low elevation and proximity to the ocean probably means it has only shallow freshwater aquifers. The only real solution to this problem (other than massive population dieoffs) is to develop a method of cheap and efficient ocean water desalination and pipe the water (uphill) inland for irrigation and potable use. Existing supplies can be stretched considerably by more efficient use and conservation, but ultimately it’s an unsustainable (even if renewable) natural resource at current and future population levels and demand.


Submit it as a Cecil/Mailbag question to Dex and I’m sure someone will get the drop on it.


Thank you, I did just did.