What Kind of Capacity and Flow Rate Should My Water Well Have

Water pressure, well water flow and yield.

Water pressure, well water flow and yield.

One of the most common questions people ask the New Hampshire Department of Environmental Services is how much water in a well is adequate for the average home. It is an important factor when considering building or purchasing a home and, as the NHDES says, the amount of water available in a well can be as important as the quality of the water. It is also important to consider flow rate when buying or building a new home. The Federal Housing Administration (FHA) requires 3 to 5 gallons per minute for older wells and a rate of 5 gallons per minute for new wells to pass inspection.

A good place to learn more about home well water capacity recommendations is from theWater Well Board, which regulates domestic wells in New Hampshire. The Water Well Board is a seven-member group made up of representatives from the Department of Environmental Services and others including water well contractors, pump installers, technical drillers and the public. The board is responsible for protecting groundwater resources, licensing well and pump contractors, and keeping well construction records. It also creates policies and enforces standards for well construction and installing pumps. Skillings & Sons President Roger Skillings is currently the Water Well Board Chairman.

Calculating water capacity

There are a few different ways to look at the amount of water in the well. The first is water storage capacity. A standard 6-inch diameter drilled well can store 1.5 gallons of water per foot. If you know the depth of the well, the level of the water and pump depth, you can figure out the water storage capacity. Most people don’t know all of this information, but it can be figured out by consulting with a water system professional.

The Water Well Board suggests that the minimum water supply capacity for use inside a home should be at least 600 gallons within a two-hour period, or about 5 gallons per minute for 2 hours. Here you will find a chart that describes the water flow rate recommendations further. Some homeowners may find this recommended amount to be less than they ultimately need depending on the size of the family or if there are large outdoor water demands. This is also something you can discuss with a water system professional.

Calculating a water well's flow rate

When evaluating a well’s water supply, the first test done is typically a flow rate test. The flow refers to the amount of water coming from the well and the flow rate measures the gallons per minute coming out. The average American household needs 100 to 120 gallons per person per day, and a flow rate of about 6 to 12 gallons per minute. This requirement may be higher if it serves a home housing a large family or there are large water demands.
The Water Well Board and the New Hampshire Water Well Association, a group of private professionals associated with the well water industry, both recommend a flow rate of 4 gallons per minute for a 4 hour period. That’s equivalent to 960 gallons of water flowing steadily for 4 hours. These groups agree these results will ensure optimum water supply for home use and a modest amount of outdoor use.

This amount of water may be less than is needed for some families, especially if there is significant outdoor water use, which is why well professionals may recommend a minimum flow rate of 5 gallons per minute or more.

What to do if my well yield falls short?

If after conducting a flow rate test, the well does not meet the recommended standards, there are some options to increasing flow. If there is space on the property, another well can be dug. This is also costly, time-consuming and may not get the results the homeowner needs. We recommend using a process called hydrofracking, which blasts water into an existing well bore to clear debris and open fissures allowing water to flow through the bedrock.

Hydrofracking or hydrofracturing does not use chemicals and is different from the hydraulic fracking associated with the oil and gas industry. The Skillings & Sons method has a 98 percent success rate and we are so confident in our process that we offer a guarantee. Contact us to learn more.