The Norwesco 1700 Gallon Underground Water Storage Cistern Tank is a buried polyethylene cistern built to sit below grade and hold up to 1,700 gallons of stored water for rural homes, cabins, fire-reserve, and off-grid supply. It molds in one long horizontal profile that drops into a single excavation rather than standing above the ground, and the shell is polyethylene with a 1.9 specific gravity rating - well above water's 1.0 density, so the wall carries structural headroom for the burial and backfill loads it lives under. It ships from the nearest stocking Norwesco plant, so you draw from the location closest to your install site.
Will it work for your install?
Underground tanks live or die at the bedding and backfill, not at the shell - so plan the install before the tank arrives. Filled with water, the contents weigh about 14,178 pounds, and the tank carries a maximum rated contents weight of 26,938 pounds. That load passes into the surrounding soil, which means the soil is structural: a properly compacted bed and even backfill carry it, while voids and uneven fill are exactly where buried tanks fail. Get the dimensions straight before you dig - the footprint (plan area for the excavation) is 55 x 135 inches, and the full envelope (the excavation volume you remove) is 70 x 55 x 135 inches. The 1.9 SG rating is the structural margin doing its job here; this remains a water cistern, so keep it on water storage and aggregate water sources such as rainwater and grey-water reuse, not chemical service.
Burial depth, fittings, and the dig math
The tank stands 70 inches tall - roughly 5.8 feet from the bed to the top of the shell before any soil cover. Your total excavation depth is that 5.8 feet plus the cover depth you need to clear the local frost line and stay above the water table, so check both before you set the dig. Fitting and manway locations are shown on the technical drawing on this page; call 866-418-1777 to confirm thread sizes for your inlet, outlet, and access before you plumb and backfill. To match tank volume to household, cistern, or fire-reserve demand, run the numbers through our Tank Sizing Calculator and the Tank Sizing Guide.
Sizing it into a real water system
A 1,700-gallon underground cistern is a common backbone for rainwater harvesting trains and reuse storage, where the buried tank keeps water cool and out of sight. If you are designing storage for grey-water, rainwater, or HVAC condensate aggregation, our guide on industrial water reuse tank topology walks through quality-banded storage trains and stage sequencing. For private fire protection, the fire-water reservoir tank design guide covers NFPA 22 sizing discipline and freeze protection for cold-climate sites. Before you commission the install, the hydrostatic test methodology guide lays out the water-fill, settlement-monitoring, and hold-time math for accepting a new underground water tank, and the concrete pad sizing guide covers the load-bearing framework if any part of your system stays above grade.
The mistake to avoid
The most common underground-tank error is treating it like an above-ground tank and skipping the engineered bedding and backfill. At a filled weight near 14,178 pounds and a 26,938-pound rated maximum, the surrounding soil is part of the structure - it must be supported correctly or the buried shell takes loads it was never meant to carry alone. Match your excavation to the 70 x 55 x 135 inch envelope, follow the burial detail on the technical drawing, and confirm your local code requirements for buried water cisterns before you backfill.
This tank ships LTL freight, quoted live to your ZIP from the nearest stocking Norwesco plant - Griffin, GA; Hanford, CA; Lancaster, OH; Owego, NY; Shawnee, OK; St. Bonifacius, MN; Tooele, UT; or Washougal, WA. Get a freight estimate in seconds with our Freight Cost Estimator, or call 866-418-1777 to confirm fittings, lead time, and the closest shipping point for your project.
