How big should my water storage tank be?
Water storage tanks come is many different sizes, shapes colors and materials. The key factor that should be considered is the volume of water the storage tank can hold. This post will help you understand the factors that need to be considered to determine the size of the storage tank. If you are wondering if you even need a storage tank, check out some of our other posts including Do I Need a Water Storage Tank?
In general we recommend that water storage tanks should be sized large enough to meet local fire code requirements plus an additional 2 days of water supply for your irrigation and household needs.
Napa County requires rural homes that are not within reach of a city fire hydrant install 2500 gallons of dedicated fire storage. In addition, new homes are required to have an additional ~800 gallons of water available for the fire sprinkler system. Right off the starting line a 3300 gallon tank is the minimum for a newly build house, but this doesn’t account for any actual water use for the house or landscaping and you don’t want to be dipping into your dedicate fire supply!
With the above requirements in mind we recommend a 5000 gallons of water storage as a baseline, leaving 1700 gallons of water as a buffer to cover instances such a low well yield or submersible well pump maintenance. For large properties with significant landscaping and a large home we recommend a minimum of 10,000 gallons. If you have don’t have to worry about meeting fire protection requirements we recommend a minimum of 2500 gallons of water storage for most homes with 5000 gallons for larger homes/properties. Please contact us to discuss your particular situation and questions.
Tank size and type considerations:
Plastic (HDPE) storage tanks can be obtained in many sizes, but the best price points are for plastic tanks that are 2500 gallons, 3000 gallons and 5000 gallons because they can be transported via road without any special permits and can be installed very quickly. As long as the same size is chosen, multiple plastic tanks can be used to increase storage capacity by placing the tanks side by side. Check out Norwesco, a storage tank manufacturer to see what sizes and dimensions are available. Oakville Pump Service stocks and installs these storage tanks, please contact us for pricing on tanks and installation.
Cement tanks are also a good option but must be installed by a qualified contractor to ensure they do not develop cracks or have other failures. Cement tanks are commonly available in 5,000 and 10,000 gallon configurations and, while fire resistant, cost significantly more than their plastic cousins.
Steel tanks are yet another option and are often chosen for their aesthetic value when the only location for the storage tank is in highly visible location . They can be customized as to height and diameter. Custom linings or coatings can be applied to minimize corrosion-the biggest drawback that metal tanks face. Because of the custom nature of steel tank construction, costs are much higher than their plastic alternatives.
If you’re considering a storage tank, please call one of our staff at (707) 944-2471 to discuss the type and size of storage tank that would best meet your needs! They will make an appointment with you to review your water needs, the water supply available from your well or spring, help you find a suitable location for a storage tank to be installed and help you through the entire process of ensuring a reliable and adequate water supply for your needs.