In some neighborhoods, the ground is giving way at a rate of four inches a year as water in the giant aquifer below it is pumped.
The groundwater has been so depleted that China’s capital city, home to more than 20 million people, could face serious disruptions in its rail system, roadways, and building foundations, an international team of scientists concluded earlier this year. Beijing, despite tapping into the gigantic North China Plain aquifer, is the world’s fifth most water-stressed city and its water problems are likely to get even worse.
Beijing isn’t the only place experiencing subsidence, or sinking, as soil collapses into space created as groundwater is depleted. Parts of Shanghai, Mexico City, and other cities are sinking, too. Sections of California’s Central Valley have dropped by a foot, and in some localized areas, by as much as 28 feet.**
This is a great news article, and it’s something we’re all going to be hearing more and more about for the rest of our lives. It continues at the link.
Groundwater is not a long term solution to water issues is what these cities areas are finding out. Aquifers not an infinite resource. They need to be used sparingly so they are given time to replenish. However many of these places are overusing them, leading to subsidence. Eventually the aquifer will be so drained that no amount of time will be able to refill it.
Oh, we can do that. A few months ago, San Diego, California opened a desalination plant which can produce 50 million gallons of fresh water per day.
However, desalinated water is expensive water. Cities in developed countries, if their back is to the wall, might be able swing it with a tax increase (and a lot of grumbling from residents.) However, agriculture would likely find it uneconomical.
What we need is an inexpensive means of desalinating water, and one which has minimal environmental consequences.
Yes, but that is only to cover the cost of the new desalination plant. Unfortunately, that plant will only provide about 8% of San Diego County’s needs. If similar plants were built to provide all of San Diego’s needs, the surcharge per household would be around $60/month. This would be in addition to the regular cost of metered water.
My point is that desalinated water is expensive water. Pretty much any other source will be cheaper, including building diversion canals. In the US, the abundance of fresh water sources have been a hindrance to large scale deployment of desalination.
Of course, when the groundwater and aquifers fall perpetually short, then more expensive alternatives will be considered. The long-term water situation in California may require this.
On the other hand, the lure of inexpensive water is great. During the past drought, many urban Californians decried the amount of groundwater allotted to agriculture. Political pressure to decrease that allotment, and increase the share given to cities, may develop. If successful, the increase in cheap groundwater may make the more expensive desalinated water a tough sell to the voting public.
One is local control. Yes, bringing water in from long distances by canal is wonderful … MAY be cheap … maybe not. But you have to go through other peoples’ jurisdictions. Eminent domain. Political deals.
Whereas, if you get the water locally, for example, sea water for desalination … then you control both ends of the supply situation.
Second, six dollars per month is not a big deal.
Third, there are other ways of doing this. Depending on where you are located.
FOR EXAMPLE, there is a HUGE GINORMOUS aquifer in the midwest. The northern region floods in a major terrible way, pretty much every year. That aquifer is pumped out in Texas, in the south end of the aquifer. It would be a relatively simple matter to construct recharge wells in the north end to increase the amount of water that would normally trickle down to recharge the aquifer.
If you have floods, then you have water.
Arguing that one method is cheaper than another can lead to false economies.
But Texas can contract with Missouri or Nebraska for construction of wells to recharge the Ogalala [sp?] Aquifer.
If you visit Google graphics you can see the extent of the aquifer.
Check the mapping for your own area.
California water rights politics is diffeerent from other parts of the country. You have to deal with how they do it there.
The Oglala aquifer does not underlie Missouri. It’s at quite a distance, and it’s all uphill from Missouri to the land overlying the aquifer.
There is a lot of “groundwater” in Missouri, particularly in the Ozarks which has karst geology. Layers of limestone interspersed with layers of chert and sandstone provide a huge layered reservoir. Ultimately, the upper layers go into streams and rivers, all of which ultimately feed the Mississippi River, and the excess water ends up in the Gulf of Mexico.
Most of the Oglala aquifer is in country where the rain is not very plentiful.
So, while waters of the upper Missouri River might be redirected into the Oglala aquifer, other manmade recharge sources would be few and far between, I would think.
Hey Ridgerunner, I’m just curious, where does the water in your area come from? :shrug: I mean, I’m just entirely used to watching huge sea barges carrying these gargantuan bags of fresh water from Northern California down to Southern Cali. I’ve seen that go on for decades, and I’m completely used to it. :shrug: But I don’t know. I mean, I think it’s right right that water is parcelled out to whoever needs it, but I have literally zero experience with how it works elsewhere, away from the West Coast. Do you happen to know where it’s routed from? Is it just basically from the Mississippi somehow or other?
It comes from rain; nearly four feet of it annually. There are some natural features that tend to conserve a lot of it without anybody doing anything. The geology (called “karst”) consists in very deep layers of porous limestone and occasional sandstone that will hold and gradually leak water downward. The water gets trapped in many, many alternating layers of chert (it’s a type of flint) that water won’t penetrate. It just sits on top of the chert layers until it spills over and downward through cracks or cave-ins into lower layers that eventually break out into springs, streams and rivers.
Below those “breakout” places, the water just sits, for the most part, though some of it flows very, very gradually into other areas. Some deep layers are under so much pressure that if you sink a well into them, the water will rise to the surface as artesian wells. Some of the pressure is due to the rock itself, magnified by the slow infiltration of rainwater through the limestone layers into ever deeper layers. The limestone acts as a filter, and the outflows are therefore very, very clean, mostly with no bacteria at all.
So, in answer to your question, it’s all just rainwater that goes into an absolutely enormous storage catchment of rock, layer after layer after layer. It’s kind of unusual.
A possibly interesting story. A few years ago we had a terrible spring drought. Some of the shallower wells began to run water that was gold. Not yellow, absolutely gold. If you let it sit overnight, it would turn red. People were alarmed and had it tested. The “gold” was iron pyrite; “fools gold” washing out of a fairly shallow layer containing it. It was gold in color coming out of the ground, but when exposed to oxygen for awhile, the iron pyrite would “rust”, turning red. It was harmless, but it was certainly odd.
In normal times, the filled layers kept the pyrite-laden water in its level with little ever escaping, but when the pressure dropped enough to let it flow out, it concentrated the “fools gold” water causing the phenomenon.
I should have added. It doesn’t come FROM the Mississippi, it flows INTO the Mississippi via the springs, streams and rivers that come out of the limestone. It’s just rainwater, very often rainwater that fell years or even centuries ago. The rain just keeps filling it back up.
There are a few people who are very good at developing water resources.
One fellow … I will post his name … has made it a standard practice to develop gardens in desert regions using available moisture.
When I proposed an experiment of taking advantage of a flooding stream and a near by detention / retention pond at a parking lot … an inexpensive experiment … pumping some excess water into the empty detention pond and allow that to help recharge our aquifer, the reaction was violent. Even though ground water recharge was and is the state policy, they wanted nothing to do with it.
Instead they prefered to let the rain water escape to the ocean.
In California, they let vast amounts of rain water run downhill to the ocean. It could be captured and pumped to reservoirs.