How Deep Does A Borehole Need to Be?
Drilling a borehole for household use will usually range from about 100 feet to 500 feet deep, but when drilling a new borehole for your home or business, the depth of the well depends on the geology and underground water levels of the area. Borehole drilling companies use their expertise, experience, and educated guesswork to determine how deep the well needs to be. Because the depth of the well can affect the price, it’s important to find a company with the skills to give you an accurate estimate before drilling starts.
Borehole water comes from underground aquifers, which are pockets of water within the bedrock, located at different depths. A bedrock well is one that is drilled into solid rock, creating access to the water that flows through cracks in the rock. Most household boreholes are about six inches in diameter and have a six-inch casing or liner. The casing is installed in the bedrock to keep surface water and sand out of your well. In many cases, a seal is installed at the bottom of the casing to create a seal in the bedrock. On the surface, the casing will be about 12 inches above the ground.
Throughout South Africa, water is often found at about 300 feet, but boreholes for household use usually range from about 100 feet to 500 feet deep. There are some places, however, where a well can be more than 1,000 feet deep.
How deep the drilling company must dig for your boreholes determines the basic cost, since most companies charge by the foot. A borehole drilling company can get a good idea of how deep the borehole will need to be by examining your property, the average well depth for your area, the geology, and other factors. If after an initial drilling, there is adequate water available for your family’s needs, then the drilling can stop. If not, the drilling will continue until a suitable water source is found.
If a good source isn’t immediately located, the borehole’s yield can be increased by blasting the bedrock around the drill hole with high pressured water to open access to cracks in the rock that carry water. This process is called hydrofracking and can help increase a water supply even after the well is in use.
Water quality is also an important consideration and depends greatly on the geology and water bed in your neighbourhood. A general rule to remember is the deeper the well, the more likely you will have minerals in your water. This is a problem that is easily fixed by installing a water softener to your well system.
When thinking about installing a well, it’s also good to set aside a few days for the work. It usually takes about a day to complete drilling, and another day to install the pump.