The Norwesco 600 Gallon Underground Water Storage Cistern Tank is built for buried water storage where an above-ground tank is impractical or unwanted. At 47 inches tall, 51 inches wide, and 101 inches long, this horizontal polyethylene cistern holds 600 gallons on a 51.0 x 101.0-inch footprint - a workable fit for cistern installs, rural water storage, and supplemental supply that needs to stay out of sight and protected from sun and freeze exposure. It is the kind of underground water tank buyers reach for when an exposed storage tank is not an option.
Does it work for your site?
This Norwesco tank is molded from polyethylene and carries a 1.9 specific gravity rating - the heavy-rated wall, not a baseline. For water at SG 1.0 that is substantial structural margin: filled with water it carries 5,004 pounds of contents, while its maximum rated contents weight is 9,508 pounds. Read that 9,508-pound figure correctly - it is contents headroom, not a burial-depth or traffic-load rating. Nothing here makes this a drive-over tank, so confirm cover depth and any vehicle loading separately. Because it is buried, the install environment - backfill type, compaction, and groundwater - drives the outcome as much as the tank. Size your storage against real demand before you commit: the Tank Sizing Calculator and Tank Sizing Guide translate daily draw and refill cycles into the right gallon capacity, so a 600-gallon cistern is a deliberate choice rather than a guess.
Reading the technical drawing before you order
Fittings and outlets on this cistern are molded and fixed by the technical drawing on this page - they are not selectable on this listing. Match the molded outlet size and gasketed fitting and riser locations shown on the drawing to your inlet, outlet, and access plan before you order, since the drawing is the authority on where those points sit relative to the tank body. Cross-check the 47-inch height and 51 x 101-inch footprint against your excavation plan so the hole, bedding depth, and any riser routing are sized correctly the first time.
The mistake to avoid on a buried cistern
The most common error with an underground tank is treating the hole like an afterthought. A buried polyethylene cistern depends on the surrounding backfill for support, and improper bedding - rocks, debris, or poor compaction against the tank walls - is the failure mode to plan around, not the wall itself. Equally important: before you bury it, prove it holds. Running a controlled water fill and watching for fitting leaks and settlement while the tank is still accessible saves you from excavating a buried problem later. Our guide on hydrostatic test methodology for new-install tank acceptance covers the fill discipline, leak detection, and hold-time math that turn a new install into a verified one.
This water storage tank ships LTL freight, quoted live to your ZIP from the nearest Norwesco plant - Griffin, GA; St. Bonifacius, MN; Tooele, UT; or Washougal, WA. Get a real number for your delivery with the Freight Cost Estimator, or call us at 866-418-1777 and we will quote the underground cistern, confirm fitting and riser locations against the drawing, and route it from the closest plant to keep your freight tight.
