Rain falling from storms over Florida lands on the ground. A combination of three different things then happens to it. (1) Some of it evaporates back up into the atmosphere. (2) Some of it runs off via streams, rivers and lakes to the ocean and Gulf. (3) Some of it seeps into the ground and forms the freshwater supply for ALL the wells of the southern half of the state. A substantial portion of this underground water becomes stored in natural underground structures known as aquifers, specifically the Biscayne Aquifer. Another substantial supply is in the similar Floridan Aquifer. These aquifers are essentially porous materials (like sand or sandstone) surrounded by relatively impermeable materials (like clay or shale) that effectively act as giant natural underground storage tanks. The surrounding materials are NOT absolutely water-tight, so water can leak out of or into the aquifers, depending on hydrostatic pressures and other factors.
These aquifers are the ONLY significant sources for the fresh water supply for the southern half of Florida.
Traditionally, the amount of rain falling on the state of Florida has supplied plenty of fresh water to keep this underground supply continuously replenished. For example, the Everglades areas receive about 55 inches of rain per year. The situation was always such that the water table (the depth at which the top of this underground seeping moisture is) was always substantially above sea level. Around the perimeter of the state, areas soaked with this fresh water had this higher water table than the adjacent areas under the ocean or gulf that is soaked with salty ocean water. Everyone knows that water seeks its own level. (Technically, this is that hydrostatic pressure stuff.) The result was always that the fresh water areas had greater water pressure and the water tended to slowly seep OUTWARD toward the ocean and gulf. This situation was fine, and stable. For millions of years, this was the case. (The situation is complicated somewhat by the different densities of fresh and salt water, but essentially, the above description is accurate.
By the early 1990s, numerous investigations had confirmed that the enormous removal of fresh water had lowered the water table, to a point where some parts of the water table were already BELOW sea level. More than ten years ago, scientists already knew that seawater had already intruded into some areas of the Biscayne Aquifer.
During the 1990s, even greater amounts of water were pumped out to irrigate an ever growing, ever more profitable fruit industry in Florida. This continuing process continues to lower the water table level. This is the making of a true disaster.
There was already a similar experience involving massive pumping of groundwater for irrigation of crops in California. In the 1950s and 1960s and 1970s, farmers had pumped SO much water from the fresh water supply under one of the main growing valleys (the San Joachim valley) there, that the land itself was no longer adequately supported and it has subsided (collapsed and lowered) over 30 feet!
If such incredibly massive water usage was to occur in Florida, the growing fields themselves could be far below sea level within a few decades, and eventually the Ocean or Gulf would claim that area for its own. Obviously, that cannot be allowed to occur! Hopefully, the farmers who are pumping all that irrigation water out, can look past the great profits they are presently making, and can become aware of the California experience and will take steps to avoid having the salty ocean or gulf flood in to create a huge inland saltwater sea in the middle of Florida.
Amazingly, those farmers who irrigate all of those orchards actually have practical selfish reasons for keeping the water table depleted! It turns out that when irrigation is used for many years, the very slight natural salinity of that water gradually accumulates natural salts on the surface and in the water in the underground aquifers. Farmers have discovered that, if they allow the water table to rise to too near the surface, their plants are seriously adversely affected by that salt and their crop productions drop off drastically. Therefore, those orchards in central Florida would NOT want the aquifers to naturally replenish themselves because their crop yields would be hurt, and therefore their profits!
Consider again that boundary area between the ground that is soaked by fresh water and that soaked by seawater. Remember also that water is destined to seek its own level. Under the present circumstances, with some areas of the freshwater water table well below sea level, there is certainly already a slow but consistent seepage of seawater INWARD under the perimeter areas of Southern Florida. This was suspected by around 1990 and has been proven experimentally since at least 1995. Many studies have documented the continual incursions of the salty seawater into the Biscayne Aquifer and elsewhere. The actual interaction between freshwater and the higher density seawater is a little more complicated than this, because local hydrostatic pressures are modified by these density differences, but the basic fact that seawater is continuously seeping farther and farther under the perimeters of Florida cannot be denied.
The boundary between freshwater and seawater is therefore slowly moving inland. When that boundary gets to the location of the well of a city, that city's water supply will become immediately contaminated and unusable. The water from that well will rather quickly become extremely saline. There will not even be any hope of the situation quickly becoming better. It will certainly take decades and possibly centuries before Nature could reverse the situation. Assuming all irrigation pumping ceased (probably by State statute), it will certainly take a number of years for rains to replenish the ground water that had been depleted for decades. Once the freshwater water table was again several feet above sea level, many years more will pass while the freshwater again pushes the seawater back to the ground under the ocean and gulf. Even then, possibly hundreds of years from now, wells might still be partially contaminated, because the salt and other contaminants will already be in the soil. It could be hundreds of MORE years before the salt and contaminants will be finally leached from the soil around the wells. This potentially means that, once a well becomes contaminated with seawater, it might be more than a thousand years before that well would again provide water that was safe to drink!
Unfortunately, southern Florida's population has tended to primarily live in areas on the very perimeter of the state. This has disastrous consequences. Nearly all of the municipal wells are within a few miles of the ocean or gulf. Once ONE city finds its water supply contaminated by the salt and other chemicals of seawater, virtually every other city in South Florida will find itself in the same situation within days or weeks. It will not be possible to deal with and try to find solutions for the disaster of a single city. ALL cities and towns in south Florida will find themselves without ANY source of fresh water almost concurrently!
A main reason for this article is to try to minimize the panic that is certain to occur at that time. If the public gets the impression that no one has thought about the consequences of such a catastrophe, the panic is certain to be widespread. If, instead, the public gets the impression that some sort of contingency plan exists, hopefully rationality will remain common. It would be nice to think that this essay is just speculative thinking about some "remote, potential" disaster. But the reality is that the damage has already been done and that nothing that could be done now can avoid it. Unfortunately, even if all the growers immediately stopped irrigating their fields (and they won't!), it would be a number of years before the situation underground would stabilize enough to slow the incursion of saltwater toward all of the wells.
Under emergency circumstances, let's say that it would be possible for a family to get by on one-fourth of that rural figure, about 20 gallons per person per day. There will be nine million people without ANY water that will each need 20 gallons per day. This is 180 million gallons of water necessary to be made available somehow, just so the population could survive! This doesn't even involve the large amounts of water needed by industry, commercial, office and government facilities. Considering the hot climate of South Florida, the 20 gallons per person per day might even be too low a figure for general survival. So, we will look at that figure of 180 million gallons per day as being an absolute lowest limit, with practical needs probably far in excess of that.
Where could 180 million gallons of fresh water be obtained? A long-term solution could certainly be developed. Certainly, after a number of years, thousands of desalinization plants could be created, and rainwater collected. After twenty years, it may be practical to supply 180 million gallons of fresh water per day by such methods locally, without using any wells. Keep in mind that the contaminated wells are likely to remain contaminated for hundreds of years!
For an immediate solution, the problem is immense because of that astounding quantity of water that must be supplied every single day. Certainly, rapid and massive construction of pipelines from areas more inland would quickly be initiated. Within a few months, such operations should be able to transfer 180 million gallons of fresh water from inland wells that have not yet been contaminated by the seawater. That solution may have limited success, however, because the seawater will continue to seep inward for many years, eventually probably contaminating those wells, too. This would be likely to occur because that such heavy use of those inland wells would not allow natural replenishment of the water table by rainfall.
Even this would take several months to arrange. Those days before the interim wells and pipelines are complete represent a crisis situation. For the first few months, then, there is an urgent and critical need for 180 million gallons of fresh water, and no obvious supply for it. The only apparent immediate solution seems to be to truck in as much as possible from fresh water supplies in Georgia and Alabama and Northern Florida. A highway tanker truck has a capacity of about 5,000 gallons. Assuming they can all be adequately cleaned from whatever cargo they used to haul, this would involve 36,000 round trips every day for such trucks just carrying water, just for the mere survival of the residents of Southern Florida. That is about a full truckload of water every TWO SECONDS, day and night. Those trips would likely take at least 8 hours round trip, so if about 15,000 tanker trucks were used 24 hours a day, every day, such an effort might be able to avert an even worse health-related situation. The resultant convoy of tanker trucks would effective be permanently and continuously bumper to bumper running up and down I-95! Unfortunately, there are nowhere near that many available tanker trucks in Southern Florida, particularly ones that could be cleaned well enough to carry drinking water.
Ocean-going ships might be able to help, again, if they could have their cargo areas cleaned enough to carry potable water. The very largest ships afloat might be able to transport 20 million gallons of water per journey, the cycle time per journey probably makes that possibility unrealistic.
Can you imagine what the cost of fresh water will be in such a situation in southern Florida? Wow!
Attempting to collect rainwater might be possible. Since about two-thirds of rain that falls quickly evaporates back into the atmosphere, it might be possible to quickly develop some new technology to collect rain from large areas before it has a chance to evaporate. This probably will not entirely solve the crisis, but it may alleviate it to some extent. Most of the state of Florida has substantial annual rainfall.
On an individual basis, people who have substantial property available might arrange such extended rain collection operations on their property. Unfortunately, there are many dangers related to doing this. There is little doubt that some desperate people are going to try to collect the rainwater that falls on their house roof and collects in their gutters. Such water would be OK for flushing a toilet but would be dangerous to use for any potable reasons. Before that rain occurred, the roof accumulated an assortment of pollution from many sources. When the rains came, they wash all those contaminants off the roof and into the gutters. VERY unsafe to drink or use for food processing!
Even if people set up some specific rain collection structure, this same problem can be significant. Unless the collection surfaces were protected from pollution until just before the rain fell, these contaminants would be present in the collected water. Worse than that, even if absolutely perfect collection methods were created, several types of pollution would still exist in the collected water. The raindrops themselves, as they fall toward earth, collect pollution from the atmosphere. One of the most known types is the famous "acid raid" but raindrops bring a wide assortment of pollution types to the ground.
Actually, Nature has always provided a method for dealing with this! After that contaminated rain has fallen on the ground, as some of it seeps into the ground, and eventually the aquifers, there is a filtration effect where the contaminants are removed from the water! Of course, in the situation being discussed here, the aquifers will be unusable for this purpose because they will have become contaminated with salinity and other minerals from encroaching seawater!
Desperate people will also doubtlessly collect pondwater and draw water from lakes and streams, assuming those sources to be safe and pure. It may occasionally be safe to do this, but in many cases, such choices will lead to massive health dangers. Standing water tends to accumulate bacteria and other organic contaminants that cause many dangerous and sometimes fatal diseases. Even lakes and streams are likely to contain chemical runoffs from pesticides, herbicides and industrial chemicals of a wide variety. It is EXTREMELY dangerous to collect drinking water from any such source of unknown purity.
What COULD be done is to drastically reduce present and future groundwater depletion, particularly by irrigation for orchards and by many industries. Will these companies voluntarily do this? Knowing that it will reduce or eliminate their vast profitability? Unfortunately, no. This being America, they will continue on a shortsighted pursuit of immediate profits. In the same way that virtually no companies have made significant changes because of scientists warnings about global warming for the past 30 years, because they chose to believe there was no absolute PROOF of the allegations, they will certainly not act to seriously damage their own profitability in this matter. Only once the first city well is contaminated and closed, quickly followed by ALL of the hundreds of other cities' and towns' wells, and after subsequent new State laws banning irrigation, will they act.
In a similar way, Florida legislators cannot be expected to easily tell the most profitable businesses in the state, the citrus growers, to stop pumping out irrigation water. Those great profits contribute large amounts to the State's tax income.
There may only be one current exception to this situation. If, NOW, a number of Florida residents initiate a CLASS ACTION lawsuit against each of those large users of fresh groundwater, it may be possible to get their attention. This is probably the ONLY course of action that can have any significant value in limiting the scope of the coming disaster. If they would all NOW severely cut back on their consumption, such that rainwater infiltration began to exceed consumption, the level of the water table would cease to drop further, and would hopefully again begin to rise. If this can be accomplished soon (with results within a few years) then at least there would be some limit to the incursion of the seawater. It is absolutely certain to contaminate all existing city wells, but this course of action would hopefully preserve the potability of some inland water wells and supplies. In that case, a city might be able to drill a well 50 miles inland and pipe that safe water to their city.
Here are the bases for such a Class-Action suit. As a direct result of their depleting the ground water supply, the water table is becoming lowered, which will certainly (effectively permanently) allow the various chemicals in seawater to contaminate virtually all fresh water wells in Southern Florida. Nine million people would thereby be immediately and drastically affected, including their lives and their livelihoods. There is a certainty that serious health considerations would result, including a number of deaths directly attributable to the lack of potable water. In addition, nearly all property values will quickly drop to near zero, since the effects of the contamination will certainly last decades and possibly centuries. Few future people would want to live in an area where water was not generally available, particularly since lawns and greenery would likely die from lack of sprinkling. Virtually all tourist business would quickly vanish, as well. How many tourists would want to vacation in a rather desolate-appearing ghost-town environment? Many businesses (such as manufacturing) that depend of significant supplies of fresh water may be forced out of business or to move to some other state or country, unless some specific solution could be found for that company's unique needs. The population of southern Florida would certainly nearly all see cause to consider leaving the State, abandoning their now nearly worthless property. The whole southern half of the State seems quite likely to eventually become a giant version of the ghost towns of the Old West. After the citrus growers are banned from irrigation, those companies are certain to move their operations to other countries, with many consequences to Florida, including a tremendous loss of revenue for State government, thereby causing reductions of services to the population.
For these reasons, and many others, the companies now depleting Southern Florida's ground water supply will certainly be sued after the fact. But, then, it will be far too late, and they will each then probably just declare bankruptcy as a result. They will each certainly have planned ahead enough to move their (profitable) operations to other countries. NOW, they are each very profitable (and subject to American justice) and know that they are in a position to actually lose something, if a Class Action suit is brought against each of them now.
A Class Action suit brought against the citrus companies now, attaching liens on their world-wide corporate assets against the damage that is certain to be caused in the future by their actions, should get their attention. They must be brought to realize that their present huge profits cannot be at the future expense of all civilization in southern Florida and that they should be accountable for that liability. Hopefully, as a result of such a Suit, those companies would have to institute more intelligent long-term planning regarding their water usage.
This is extremely urgent!
This web-page was first placed on the Internet in September 1997.
In Italy, the city of Venice has been slowly sinking downward for at least the past several centuries. It has gotten to a crisis stage for them, as the Mediterranean Sea regularly floods the city now. Many historically important buildings and artwork are in constant danger of unusually high tides and large waves caused by severe weather.
In the middle 20th Century, many wells were drilled in the area, to obtain fresh water for drinking and all the other purposes. The city leaders were soon horrified to discover that their city was sinking even faster. They soon realized that it was due to the many wells drawing a lot of water out of deep soil, which was allowing the layers above to collapse due to gravity, a process called subsidence.
They obviously immediately ordered those wells closed, and the rate of subsidence soon slowed to its usual rate.
My recommendation to them was to again use those many wells! But NOT to draw water OUT, but to pump large amounts of fresh water INTO the wells. If they would be able to pump more water into those deep soil layers than was able to seep outward, they will build up water pressure, which will certainly raise their city back up! I have done some preliminary calculations to suggest that they may be able to raise their entire city by around three feet over a period of around five years. Since there is no downside (no environmental consequences, very low cost, and existing wells), it seems prudent for them to immediately start doing that. The alternative they are currently considering is to concede that their city will continue to sink and to spend between two and three BILLION dollars building an untested idea of having movable steel walls in the nearby ocean, so they could open and close them! It turns out that that plan, separate from still having their city sinking, has a number of potential environmental problems.
In any case, it has occurred to me that the same general idea might be of some use in Florida once the Municipal wells have become contaminated by infiltrating seawater as described above. If NOTHING is done, and natural rainfall is relied on to gradually fill the aquifers again, which would gradually seep outward toward the ocean (as it had done for hundreds of thousands of years!), it seems certain that many hundreds or even thousands of years will be needed before the sands and rocks of the aquifers are again cleaned of the salt from the ocean. During all those hundreds of years, the southern half of the State of Florida will have no usable wells at all, essentially no fresh water, and so that huge area would have to remain uninhabitable (as described above).
However, there might be a glimmer of hope! IF, IMMEDIATELY on knowing that the Municipal wells have all become contaminated, ALL wells would be ordered stopped (which is all certain to happen anyway), and then, large pumps then begin to constantly pump freshwater DOWN all those wells, a much faster recovery might be possible. It is unclear where that much (fresh) water could come from, but if it could be obtained, the aquifers might soon (a few years) be filled again to a level above sealevel. That would stop the advance of the inwardly seeping saltwater in perhaps just a few years. If such massive pumping was continued, the aquifers would become pressurized (much like the Venice suggestion). In the case of Florida, this pressurization should have the effect of forcing freshwater outward (seaward) through the same paths that the seawater is presently seeping inward. Over a period of following years of continuous pumping, that outwardly moving freshwater figures to gradually purge the aquifer sands and rocks of the salt, by dissolving it and carrying it out under the ocean, due to the pressure developed by the many pumps.
If and when this might be done, there actually would be a side-effect of much of the area of southern Florida should rise up a foot or two in altitude, very much like what is desirable in Venice! In the case of Florida, that result would just happen to occur, and probably would not have any noticeable consequences, except perhaps that beaches get wider!
This is not a "great" solution! But rather than allowing half of the State of Florida to become uninhabitable for hundreds or thousands of years, it might keep that period to just a decade or two.
( http://mb-soft.info/public4/index.html )
C Johnson, BA Physics, Univ of Chicago