critical condition in which water resources are depleted or so severely mismanaged that they can no longer meet essential needs of populations, ecosystems, and economies.
Glen Canyon Dam on Lake Powell in Page Arizona from Bureau of Reclamation files
The U.S. Bureau of Reclamation just issued a Record of Decision on hydrologic management of the Colorado River. It establishes a framework for operation of Lake Powell and Lake Mead. The framework is outlined in the Bureau’s Post-2026 Operational Guidelines and Strategies for Lake Powell and Lake Mead https://www.usbr.gov/ColoradoRiverBasin/post2026/final-eis/index.html. This document will replace the expiring Colorado River management agreements at the end of 2026.
Reclamation was hoping that the seven states which the Colorado River runs through and who are the primary users of the water from the river would come together and produce their own consensus-based agreement but of course that never happened, so the Bureau stepped in to make sure there was something to replace the existing agreements. The Bureau of Reclamation operates the dams on Lake Powell and Lake Mead so that is their main focus. There has to be enough water in the lakes to operate the dams. Period.
The west has been in drought conditions for years now and water levels in the lakes and in the whole reservoir system that the Bureau operates are dangerously low. Yet the lower basin states (California, Arizona, and Nevada) go blissfully on like nothing is happening. Out of control growth and overpopulation. It’s no wonder that the upper basin states of Wyoming, Utah, Colorado and New Mexico can’t make an agreement with these water hogs. Wallace Stegner the great American author wrote a book called Beyond the Hundredth Meridian that tells the tale of the whole development of western water management policy in the United States. It’s the story of John Wesley Powell whose first navigation of the whole of the Colorado River is legendary. Few people know though that Powell was the one who pushed for the western water management system that we have now. He told the idiots in Washington that there wasn’t enough water beyond the 100th meridian to support future western expansion and the idiots basically said, “so fix it.”
Now after years of drought and changes in climate conditions the truth of it all is apparent. It cannot be fixed. Even the new “operational guidelines and strategies” is admitting this because it relies on adaptive management practices. If you haven’t heard this term before, it means “an iterative method of decision making in the face of uncertainty.” Previously known quantities of water were scheduled for release on a yearly basis so water managers in states could plan. No longer. Now The ROD establishes operating guidelines through 2036 that will be determined in 2-year increments. What you get in 2027 may not be what you’re going to get in 2029, unless a broader consensus among the Colorado Basin States supports a longer duration (I’m personally not waiting for that to happen).
From what I can tell, 2027 will start with a range of possible releases of water from Lake Powell to the downstream Lower Basin States of 5.0 million acre-feet (maf) to 12.0 maf. This entails shortages for the Lower Basin of up to 3.0 maf. The Bureau plans water storage in Lake Powell of up to 8.0 maf and 3.0 maf in Lake Mead. The Bureau also is planning for voluntary Upper Basin conservation of up to 200,000 acre-feet (good luck with that).
I wrote a blog post many years ago about the poor old Colorado River and the stress that it was undergoing. You can read that post by clicking here An American River in Distress . I have been writing a lot about Water Bankruptcy recently. The definition of water bankruptcy is “the critical condition in which water resources are depleted or so severely mismanaged that they can no longer meet the essential needs of populations, ecosystems, and economies”. To read my post on Water Bankruptcy click on this link Is the World Really in Global Water Bankruptcy? . Is the Colorado River in Water Bankruptcy? This is a very good question. I’m going to attempt to answer that question in the next few months by looking at the recent hydrologic studies of the river. So as they say in the biz: “Stay tuned.”
After my last post on whether the Floridian Aquifer in Florida was in water bankruptcy (according to the definition from the United Nations University Report entitled Global Water Bankruptcy) I was contacted by a reader of this blog from Georgia. He gets his water from a small municipal system supplied by wells into the Floridian aquifer. I explained in my first post on the Floridian: An Aquifer is All About Its’ Geology that the Floridian aquifer extends into southern Georgia, South Carolina and Alabama. The situation in Georgia where my reader lives is quite a bit different from Florida. Let’s take a look and see if the Floridian in Georgia could be classified as being in water bankruptcy.
As usual when discussing an aquifer we’ll start with the geology. The Georgia and South Carolina parts of the Floridan aquifer are at the northern most edge of the broad carbonate platform that underlies much of Florida and the adjacent Coastal Plain. The Eocene and Oligocene limestone and dolostone formations of the Floridian dip and thicken towards the coast with more purely limestone and dolostones of Eocene and Oligocene age. The main formations are the Ocala limestone and the Suwannee Limestone which were deposited in shallow marine environments as lime muds, skeletal debris and reef and shoal deposits. After burial and consolidation, the carbonates were altered by recrystallization and through carbonate dissolving along fractures – similar to the Floridian’s formations in Florida. Up dip, toward the Fall Line where coastal sediments meet the metamorphic and igneous rocks of the Piedmont the carbonate formations become thinner, more discontinuous, and increasingly mixed with siliciclastic sediments.
The aquifer is overlain by younger rock formations comprised of clay, silt, sand, phosphates, and unconsolidated surface deposits of Miocene, Pliocene, Pleistocene, and Holocene age that serve to confine the aquifer and restrict surface recharge. The formations of the Floridian in Georgia are recharged where they outcrop at the surface near the Fall Line. This is very different from Florida where formations of the Floridian outcrop over much of the surface of the state and water recharge to the aquifer is direct. Because of this indirect recharge, water that enters the Floridian aquifer near the Fall Line takes thousands of years to reach the coast. I hope people who use the water along the coastal plain think about that when they leave the tap running.
Just as in Florida, the aquifer is divided into the Upper and Lower Floridian. Intervening between the carbonate formations comprising the Upper and Lower aquifer are marls and siliclastic rocks; however, they are not continuous throughout Georgia and sometimes the Upper and Lower Floridian are connected. And just like Florida, the Upper Floridian is the more prolific of the two with much better water quality, although still “hard”, containing high levels of calcium and magnesium.
The Upper Floridian has been a traditional source of water in Georgia for municipal, agricultural and industrial needs. Unfortunately, that all had to change. The reason: saltwater intrusion. I discussed saltwater intrusion in my blog on the Floridian aquifer in Florida. You can read it here ( IS THE FLORIDAN AQUIFER SUFFERING WATER BANKRUPTCY? ). In short, the formations of an aquifer do not stop at lands end. No, they continue on beneath the ocean. In Georgia it is fortunate that the formations of the Floridian are overlain in most places by fairly thick overlying rocks, so saltwater from the ocean does not intrude into the aquifer. Not so in South Carolina. Hilton Head is the offending area. The local absence and erosion of these overlying rock formations have resulted in saltwater intrusion.
As you can see from the figure above taken from the Georgia Environmental Protection Division website, the area called the Beaufort Arch is where the problem exits. In the past when sea level in the Hilton Head area, including the Calibogue Sound west of the island, was lower ancient rivers cut right through the overlying rocks and formed channels. Later these channels filled with younger porous sediments. These channels can act as conduits for seawater to move downward into the Upper Floridian aquifer.
This might not sound like all that much of a problem, but because the Floridian aquifer was so overused on the southern coastal plain in Georgia it resulted in water in the aquifer moving from South Carolina towards the centers of pumping in Georgia. All sorts of towns and municipalities in Georgia, including Savannah and Brunswick, used the Upper Floridian aquifer as their main source of water. Before this large-scale groundwater development, freshwater in the Upper Floridan aquifer moved generally from inland recharge areas in South Carolina toward the coast and discharged upward or seaward. Under those natural conditions, artesian pressure helped keep saline water offshore or beneath the freshwater system. Hilton Head had increased vulnerability because the island lies close to Port Royal Sound, Calibogue Sound, and other saline surface-water bodies that overlie or border parts of the Floridan aquifer system there. It’s not all Georgia’s fault though, after all Hilton Head Island also was withdrawing water from the Upper Floridian which lowered the water table and reversed the aquifer’s natural seaward hydraulic movement. United States Geological Survey studies of Hilton Head have clearly shown how declining aquifer pressure changed the groundwater flow direction beneath the island. Instead of freshwater consistently moving toward Port Royal Sound, portions of the aquifer began moving landward.
To add insult to injury for the Floridian aquifer in Georgia, over pumping in the Brunswick area has caused another type of saltwater intrusion. The Upper and Lower Floridian aquifers are more integrated in that area because of faulting and fracturing in the rock formations. The Lower Floridian is not of high quality. Due to over pumping this low-quality saline water was drawn upward into the Upper Floridian aquifer. The problem is most significant in downtown Brunswick.
During the 1980s efforts began in Georgia to prevent saline waters from destroying the Floridian aquifer. Georgia began limiting water withdrawals from the aquifer in the most vulnerable coastal areas, especially around Savannah. The major turning point came in 1997, when the Georgia Environmental Protection Division adopted the Interim Strategy for Managing Salt-water Intrusion in the Upper Floridan Aquifer of Southeast Georgia. The strategy covered twenty-four coastal counties and imposed caps or reductions in areas where additional pumping could worsen saltwater movement. It required areas around Savannah to reduce groundwater use by at least 10 million gallons per day by the end of 2005 and limited new withdrawals in other parts of the coastal area.
Georgia replaced the interim strategy with the Coastal Georgia Water and Wastewater Permitting Plan for Managing Saltwater Intrusion in 2006. The plan instituted a more detailed management system for the Floridian aquifer. In the Savannah area where saltwater encroachment from the Hilton Head side was a central concern, the plan continued to limit Upper Floridan withdrawals and encouraged the shift to alternative sources, including surface water. Savannah now gets its’ water from the Savannah River. Smaller communities with no access to surface water have very restrictive limits on withdrawal and major water conservation measures are in place. In Brunswick where the saltwater plume was already wreaking havoc on water-quality, the plan preserved withdrawal restrictions. Brunswick has responded with conservation measures and drilling wells into less productive aquifers to supplement their water supply. And Hilton Head? Well, they have chosen to drill a very deep well into Eocene rocks. It’s poor water quality but they have added a desalination plant using reverse osmosis to treat it.
Is the Floridian in Georgia in water bankruptcy. I say no. Good management practices early on have disrupted such a catastrophe. This hydrograph from the USGS shows the rebound of water levels in Coastal Georgia after the institution of Georgia’s aquifer control measures.
But the Floridian around Hilton Head in South Carolina might well meet the definition of water bankruptcy as once salinization occurs you’ve wrecked your water supply permanently.
Manatees enjoying a spring fed by the Upper Floridian aquifer
The 2026 United Nations University Report Global Water Bankruptcy frightened a great many people by declaring much of the world is currently in water bankruptcy – the state of water resources being so overused and degraded that they cannot be restored to their original condition and function. It caused me to contemplate how much of our water resources in the United States are in this state of collapse. Might as well start with our most prolific, so I took a look at the Floridian aquifer in Florida. It is probably the country’s greatest aquifer and supports human consumption, agricultural irrigation, and industrial needs.
The Floridian aquifer underlies Florida, the southern parts of Georgia into coastal South Carolina, and parts of southern Alabama. It is a limestone aquifer and if you want to know something of its geology in Florida you can check out my blog post here ( The Floridian: An Aquifer is All About its Geology )The geology of an aquifer is important as it will tell you about flow, chemistry and a host of other important parameters. The Floridian aquifer through most of its’ extent is divided into an Upper Floridian aquifer and a Lower Floridian aquifer. The Upper aquifer is the good one which everyone likes to tap as the water quality is generally excellent and recharge from the surface and through karst features produces tons of flow. The Lower aquifer is confined in most areas by overlying thick formations of marls and siliclastics that restrict water flow into It from above. The water quality is also not very good and it is pretty deep, so drilling into it is costly for well development My attention then is solely on the Upper Floridian as to whether it is overused and degraded to the point where Floridians are going to be in trouble with water supply in the future.
The two major issues that could affect this mighty aquifer are karstification and salinization. Let’s look at the condition of karstification first. Karstification problems are most often caused by overuse. In other words, too much water in a concentrated area is being pumped out of the aquifer. Over pumping leads to increased solutioning of the limestone. Fractures, vugs and caverns all increase in size. In addition, over pumping causes the groundwater table to lower which can lead to collapse of the limestone formation. These collapsed areas are called sinkholes. Every once in a while you will see one on tv where a sinkhole has swallowed a house or road.
Most large cities in Florida have groundwater well fields where a number of wells have been drilled into the Upper Floridian. When water is pumped from these well fields it produces what is known as drawdown. Water rushes into the screen of the wells and is pumped up to be stored above ground. As the water is pumped from near the well, water further from the well is drawn toward it. A cone of depression around the well is formed. The more the well is pumped the greater the cone of depression becomes. The water table will begin to lower, and the limestone once supported at the surface by the water begins to collapse.
One of the classic examples of well-field-related sinkhole problems comes from the municipal well fields north of Tampa. The U.S. Geological Survey documented that this Gulf Coastal Plain area was already densely pitted with natural sinkholes and sinkhole lakes, and yet water authorities continued over pumping from the municipal well fields causing abrupt drops in groundwater levels. The surface began to collapse. Eventually many of the wells in the field were abandoned and to prevent further collapse pumping levels were curtailed. Alternative sources of water had to be added including river water, stored reservoir water and desalinated seawater to restore water supply to the city.
Salinization of the Upper Floridian is the other big threat to the aquifer. Salinization is the fancy scientific name when saltwater either from the ocean or from lower saline aquifers begins to intrude into a freshwater aquifer like the Upper Floridian. I’m always saying that every drop of water connects to every other drop of water on Earth, so salinization in coastal areas is quite common. The ocean and nearshore aquifers interact. If there is tidal flooding or a drought then salt water from the ocean can intrude substantially into a fresh water aquifer.
But by far the greatest cause of saltwater intrusion into the Upper Floridian is once again over pumping. When water is withdrawn faster than it can be replenished, the pressure differential allows saltwater to migrate inland. This phenomenon is particularly pronounced in highly populated areas and agricultural areas undergoing extensive irrigation.
Saltwater intrusion compromises the quality of drinking water by increasing salinity levels. Elevated salt concentrations pose health risks and can render groundwater unsuitable for consumption without costly treatment. Using saline water in agricultural operations can damage crops sensitive to salinity and in the long term result in salinization of soils rendering them infertile as nothing will be able to grow there.
Miami-Dade, Broward, and Palm Beach counties in south Florida are among the most severely impacted by saline intrusion. Dense urban development, high water demand, and proximity to the coast have accelerated salinization of the Upper Floridian aquifer. In southwest Florida the cities of Naples and Fort Myers face salinization of both potable water supplies and agricultural irrigation wells. In Miami-Dade County, saltwater intrusion has led to the closure of several municipal wellfields and the construction of inland wells. Similarly, in Tampa Bay, increased salinity in groundwater has necessitated investment in desalination facilities.
Unfortunately once saline water intrudes into an area, it can’t be reversed. Prevention is the only management strategy available. The state of Florida’s Environmental Protection Division and its’ five water management districts have teamed up with the U.S Geological Survey to put a prevention plan in place. A major component of their plan is to set Salt Water Intrusion Minimum Aquifer Levels, often called SWIMALs, for vulnerable areas of the Upper Floridan aquifer. These levels are designed to maintain enough freshwater pressure in the aquifer to slow or prevent regional saltwater movement. Another part of the state’s response is reducing dependence on fresh groundwater. The Florida Department of Environmental Protection recognizes that groundwater withdrawals cannot continue to grow indefinitely without unacceptable impacts, including saltwater intrusion, reduced spring flows, lower lake levels, and wetland losses. As a result, the state promotes alternative water supplies such as reclaimed water, brackish groundwater, seawater desalination, stormwater, surface water, conservation projects, and aquifer storage and recovery. Florida is also experimenting with aquifer recharge projects that can help slow saltwater intrusion by increasing freshwater pressure in the aquifer. Hillsborough County provides a practical example. Working with the Southwest Florida Water Management District and the Florida Department of Environmental Protection, the county has developed coastal recharge projects that inject highly treated reclaimed water into a non-drinking-water portion of the aquifer near the coast. The goal is to create a freshwater barrier between saltwater beneath Tampa Bay and the freshwater inland, while also supporting higher groundwater levels upstream of the recharge area.
So having examined the facts about damage to the Floridian aquifer in Florida can we say that the aquifer is in water bankruptcy. I think not. Salinization is localized and management strategies are in place. The Floridian aquifer will continue throughout most of its extent to be a prolific water resource.
Is The Floridian Aquifer in Florida in Water Bankruptcy?
United States Geological Survey: Crosseection of the geology of the Floridian aquifer
Florida is a big state of some 66,000 square miles and it has a lot of people, nearly 25 million. About half of them depend on the Floridian aquifer as a water source. The interesting thing is most of the people who live in Florida are not from Florida. They are from big cities up north that primarily get their water from rivers. The majority of people in Florida if asked would probably not be able to say where their water comes from and after all why should they worry, as good grief, it seems to be plentiful. It’s not like California where there are all sorts of water restrictions and you have to landscape your yard with ugly white stones instead of grass. No when a Floridian turns on the tap they let it run.
The water may be plentiful but it is deemed hard by water treatment specialists. That’s because of the geology of the Floridian aquifer. To understand an aquifer you must understand the geology. Looking at Florida on a map you see that it looks like a tail wagging the dog of the North American continent. If you look at it from the air, it looks very, very flat. This is a result of how it was formed. Some 200 million years ago the supercontinent of Pangea began to break apart. As the North American continent slowly headed towards its present day position a shallow sea developed between it and the African continent. This shallow sea was an optimum place for the deposition of carbonate rocks and siliciclastic sediments. Thick sequences of interbedded limestone, clays and sandstones accumulated throughout the Cretaceous and on into the Cenozoic geologic time periods as the continents moved further apart.
During the Paleogene, about 60 million years ago, movement of the continents began to settle into what we might recognize on our current world map and the area where Florida exists today was a shallow marine platform beginning to form the tail of the North American continent. The era was characterized by rising and subsiding seas. Geologists call these transgressive and regressive sequences. So when the seas were high carbonate and siliciclastic rocks formed and when the seas were low the rocks were exposed, leading to what is called karstification – an interesting type of erosion where limestone is slowly dissolved by water as it percolates through the rock creating, vugs, channels and caverns.
Thick cumulation of sediments were continuously being buried by further deposits of sediments. As a result the underlying sediments began to compact. The low temperatures and pressure from this compaction as well as the infiltration of meteoric waters altered the rock. In some cases the rock would become dolostones as magnesium replaced calcium in the mineral structure and in other cases secondary porosity such as fracturing and solutioning would develop.
Lack of any substantial movement of the carbonate platform through faulting, or subduction/abduction of the continental plates led to only minor amounts of deformation of the area. There are only a few gentle geologic highs, like the Peninsular Arch which trends northwest to southeast and the Ocala Platform in north central Florida.
The major stratigraphic units of the Floridian aquifer were formed during the Cenozoic from about 60 million to 20 million years ago. From oldest to youngest they are the Oldsmar Formation, the Avon Park Formation, the Ocala Limestone, and the Suwannee Limestone. The Oldsmar formation is mainly dolostone and clayey carbonates that were deposited in the shallow restricted depositional basin. The Avon Park Formation is composed of interbedded limestone and dolostones with abundant karstification denoting its formation in the era of transgressive/regressive seas. The Ocala Limestone is the most continuous formation throughout Florida of the units that compose the Floridian aquifer. It Is composed of thick limestone layers formed in the offshore environment. The Suwannee Limestone is characterized by a fossil laden limestone formed in the shallow marine environment. These rock units are variable in thickness but reach greater than 1000 feet in north and central Florida.
This is a lot of aquifer. In north and central Florida where the aquifer is at its thickest, it transmits a ton of water throughout its continuous expanse. Recharge of the aquifer is direct and extensive. Some of the most prolific springs in the world are in this area. People today flock to the beaches in Florida but at one time the springs were one of its biggest tourist attractions. Go today and you can often see manatees making the springs their home.
Southern and Coastal Florida have a thinner sequence of the carbonate rocks and more siliclastic units forming thick sequences of rock where there is little recharge to underlying aquifer units. These barriers to water transmission are called confining zones and the Hawthorn Formation is its greatest representative. In the panhandle of Florida and along the Gulf and Atlantic coasts these siliciclastic rocks units dominate.
So the Floridian aquifer is a product of its geologic formation. Its thick sequences of interbedded sedimentary rocks and karstification is why it is so prolific in some areas and not others. Its dominance by limestone and dolostone is why the water is contains so much calcium and magnesium bicarbonate and is dubbed “hard”. Its predomiantly siliclastic nature near coastal areas and at depth result in fresh groundwater mixing with more saline or brackish waters making it less productive as a water source. But without the Floridian aquifer the state of Florida would not be able to maintain a population of its size. It is one of the greatest aquifers in the world.
The recently issued United Nations University Report Global Water Bankruptcy says: “The world is already in the state of “water bankruptcy”. In many basins and aquifers, long-term overuse and degradation mean that past hydrological and ecological baselines cannot realistically be restored. While not every basin or country is water-bankrupt, enough critical systems around the world have crossed these thresholds.”
Strong words and new words. What do they mean by “water bankruptcy?’ The term is defined in the report as the critical condition in which water resources are depleted or so severely mismanaged that they can no longer meet the essential needs of populations, ecosystems, and economies. The conclusion that we are now bankrupt is based on statistics. Very interesting. Not scientific proof, just statistics.
For example, the report says that nearly three-quarters of the world’s population live in countries classified as water-insecure or critically water insecure. Insecure is the mumbo jumbo word now used to mean insufficient. So, there is basically insufficient water for the population of these countries. The report also cites that about 4 billion experience severe water scarcity for at least one month a year.
Groundwater is reported to now be the source of 50% of global domestic water use and over 40% of irrigation water and that around 70% of the world’s major aquifers are showing long-term declining trends. Excessive groundwater extraction has in turn led to significant land subsidence because when you extract water and lower the water table, aquifer materials such as sand and silt compact. Compaction basically destroys the ability of the affected acquirer to recharge itself with water. The report says that over 6 million square kilometers—almost 5% of the global land area— is subsiding due to groundwater extraction.
Our biggest source of water though is surface water – rivers, streams, and lakes. They cite that a growing number of major rivers now fail to reach the sea (like the Colorado River – see my blog post here An American River in Distress ) or fall below environmental flow needs for significant parts of the year. No statistics are provided here; it’s just based on anecdotal observation. The report goes on to say that more than half of the world’s large lakes have lost water since the early 1990s, affecting around one-quarter of the global population that depends directly on them for water security.
Very interestingly the report states that about 70% of the world’s global freshwater withdrawals are used for agriculture and that more than 170 million hectares of irrigated cropland are under high or very high-water stress meaning again that there is insufficient water for irrigation at times.
So, what does the report say is the cause of global water bankruptcy? People. Of course, they couch it in terms of the “Anthropocene” the word now used to mean the period of time since humans have started affecting their natural environment with their activities.
The chart I like best in the report is this:
The chart shows the increase in freshwater use from the early 1900’s to today. Use rose precipitously starting in the 1960’s. They should have put the chart below right next to it because it shows an identical increase in population:
Trends indicate that by 2030, demand for water is expected to outstrip supply by 40 percent, driven by population growth, urbanization, and increased agricultural and industrial use. Apparently water bankruptcy will be the norm. However, the report provides no scientific measures for determining when a water system is in bankruptcy. Case studies are cited but there is no definitive presentation of a way to classify a system as bankrupt. In my view this is the big failing of this report. It only coins a new term and attempts to define it but lacks rigor in its presentation. So, the question still remains: are we in the midst of global water bankruptcy?
I will attempt in my blog to look into large water supply systems and determine if they are indeed in a state of bankruptcy. I will start with one of the most prolific aquifers in the United States – the Floridian.
