What is a water table?
The water table is a term for describing the depth where the earth becomes full of water.
At a certain level underground, the spaces between hard matter are saturated with water, known as groundwater. The upper limit of this zone is the water table.
Where is the water table located?
How far down the water table and groundwater is located depends upon features of the surrounding environment. Areas with traditionally high rainfall and porous rock are likely to have higher water tables.
Some water tables may exist just under the surface, while others can be tens of thousands of feet down.
The easiest way to find out where the water table is to measure the depth of nearby existing wells.
Drilling companies may also use electric or acoustic probes to gain an indication. However, judging the location of a water table is often not an exact science.
What is the average well depth?
Because the depth of the water table can vary, there is no average well depth. However, most household private wells are drilled to a depth of between 150 to 850 feet.
Because well depth has a large effect on the cost of drilling, many people want to get an idea of how deep their well will be before they commit to the project.
While there’s no surefire way of knowing where the water table lies on your property, looking at the depth of neighbors’ wells should give you some indication.
How deep should my well be?
Most wells should extend down below the water table in order to create pressure that helps the water to naturally rise up the well shaft.
Exactly how far a well needs to drop below the table depends upon rock composition. Some wells may need to drill down hundreds of feet to achieve the same pressure (measured in gallons per minute) as those close to the surface.
Investing in a sufficiently deep well is worthwhile, as it can be difficult to artificially increase water pressure.
Once water passes through a filtration system and is connected to multiple appliances and faucets, water pressure can suffer.