The water in your well can return even with a slowly recharging aquifer, but sometimes it can take longer or a lot longer than what we would like it to. My dear old mom uses well water, mainly for her garden. Her well is quite shallow and is on sandy alluvium sand derived from the river. She was telling me all about how she recently got someone around to fix the pump. I had to politely explain she was not in an area that had artesian water, and that her well water comes from groundwater that moves through an unconfined aquifer the sandy alluvium.
I also had to explain that even if it was artesian water it could still run out. Artesian water is essentially water that comes from a confined aquifer, meaning it has a relatively impermeable layer above it and usually below it stopping the water from easily getting to the surface. Once you drill down through this top confining layer, you can access the artesian water. Artesian can mean the water is under pressure. In some areas, water can literally spout out of the top.
How this works is the same as filling a piece of garden hose with water. Imagine holding a short piece of hose with the two ends facing up loop at the bottom. You fill it with water — What happens? But, what if you put your thumbs over both openings, lifted one end higher and then took both thumbs off — What happens to the water now? Precipitation recharge occurs on the mountains, which migrates between two confining layers deep underground.
Depending on where your well is located and the height of the piezometric water level will determine if your artesian well flows or not.
All it takes is a reduction in the piezometric water level hydraulic head for your well to stop flowing and can even run dry. This can be caused by reduced recharge or just from high water use. In the image above, the house on the right shows a non-flowing artesian well from a reduced piezometric water level.
In truth, the water table can very easily be lowered when there are multiple wells in a given area or if one person has a high water usage — typically on a commercial property such as a farmer using the water for irrigation.
Ok, lets pretend you have a well that is producing lots of water. Everything is going swimmingly — pun intended. Then comes along a new neighbor who puts in their own well, and then another neighbor increases their use… etc.
Soon enough, you may notice your well is not producing anywhere near as much water as it used to. The more wells pumping groundwater means greater demand on the resource, which can cause your well to dry. A cone of depression refers to the shape of groundwater immediately surrounding a well. As water is being pumped upwards, the groundwater around the well becomes depleted and takes on a cone-shape that radiates outwards from the intake.
Drawdown is the difference between the original water table depth without well pumping and the cone of depression groundwater depth with well pumping. The drawdown will be greater closest to the well and least farthest from the well. Basically if your pump rate is too high, your well can dry up. Again, it really depends on your area. If a well is relatively close to another well it could be yours or your neighbors , then there is definite cause for concern as one of them could start to run dry.
A large cone of depression can influence how groundwater moves underground and will often redirect water towards it.
This means that a nearby well can literally SUCK water away from yours causing the well water level to drop or dry up completely.
In comparison, commercial wells e. The longer a well is pumped, the wider its influence on the groundwater system. Additionally, it can take longer sometimes weeks to months for the area surrounding these heavily-used wells to recover meaning your well could remain low or dry for longer. Year Published: Land subsidence in the United States This report explores the role of science in defining and understanding subsidence problems, and shows that the optimal use of our land and water resources may depend on improved scientific understanding to minimize subsidence.
Year Published: Sustainability of ground-water resources The pumpage of fresh ground water in the United States in was estimated to be approximately 77 billion gallons per day Solley and others, , which is about 8 percent of the estimated 1 trillion gallons per day of natural recharge to the Nation's ground-water systems Nace, Alley, William M. Lehn Attribution: Water Resources.
Year Published: Ground water and the rural homeowner As the salesmen sang in the musical The Music Man, "You gotta know the territory. Waller, Roger M. Attribution: Water Resources. Year Published: What is ground water?
Clark, David W. What is ground water? Filter Total Items: 4. Date published: March 9, Date published: December 14, Date published: October 11, Date published: October 6, Filter Total Items: 8.
List Grid. October 7, If such a confined aquifer is tapped by a well, water will rise above the top of the aquifer and may even flow from the well onto the March 16, Flowing groundwater site in Indiana. February 10, July 10, Flowing well used for stock water, Green River Basin. September 22, In a recent study , we mapped the locations and depths of wells in 40 countries around the world and found that millions of wells could run dry if groundwater levels decline by only a few meters.
Humans have been digging wells for water for thousands of years. Examples include 7,year-old wells in the Czech Republic and Germany , 8,year-old wells in the eastern Mediterranean , and 10,year-old wells in Cyprus. Groundwater flows through tiny spaces within sediments and their underlying bedrock. At some points, called discharge areas, groundwater rises to the surface, moving into lakes, rivers and streams. At other points, known as recharge areas, water percolates deep into the ground, either through precipitation or leakage from rivers, lakes and streams.
Groundwater declines can have many undesirable consequences. Land surfaces sink as underground clay layers are compacted. Seawater intrusion can contaminate groundwater reserves and make them too salty to use without energy-intensive treatment. River water can leak down to underground aquifers , leaving less water available at the surface.
Yet until recently, little was known about how vulnerable global wells are to running dry because of declining groundwater levels. There is no global database of wells, so over six years we compiled unique well construction databases spanning 40 different countries. In some cases your pump can be lowered to increase access to aquifer water.
Consult with a well or pump contractor to determine if this is an option. Well Construction Issues Decreased well efficiency can sometimes be associated with the following: Deposits in the well bore hold this can occur naturally and over time the deposits need to be cleaned out. A well that was never fully developed Inappropriate screening to allow for free water movement wire wrap screens are usually preferable to slotted screens.
Bacterial deposits e. DO NOT attempt to deepen your well or construct a new well without the help of a licensed well contractor. DO NOT pour water from another source into your well.
Your well is connected to an aquifer and is not a storage device. Precautionary Measures Note changes in water pressure. Reduced water pressure may be a forewarning of a lowered water table and aquifer depletion. However, keep in mind that loss of water pressure may also indicate well inefficiencies or problems with your pressure tank. Note long-term changes in water depth. Water level changes over time can serve as an early warning sign if your water supply is in jeopardy.
If you are interested in learning more about measuring your well water level click here.
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