Practical, plain-language guidance on choosing, installing and maintaining water storage, written by the Promax team.
Underground tanks free up land, stay out of sight, and keep the surface above them usable. Here's when they make more sense than an above-ground tank on a New Zealand property.
Read the guideGroundwater around an empty underground tank can compress its walls until they collapse inward. Here is how hydrostatic crush works, how it differs from flotation, and the two ways to design it out.
Read the guideOne-piece construction, built-in seismic restraints and fewer connection points. How Promax underground and slimline tanks are designed for ground that moves.
Read the guideEmpty underground tanks are buoyant, and on flood-prone or high groundwater sites they will float. Uplift restraints strap the tank to concrete-filled boxes to hold it down, and you need roughly one set for every 1,000 litres.
Read the guideRigid concrete tanks cracked in the Christchurch and Kaikoura earthquakes, and Promax replaced many of them. We have had no recorded failures of our plastic tanks after those events, which is the clearest answer we can give on material choice.
Read the guideBrowse Promax tank categories for residential, rural, commercial, and specialised applications.
Durable above-ground water tanks for rural, residential, and commercial storage.
Underground water storage for sites where space, access, or visibility matters.
Narrow-profile tanks designed for homes, boundaries, and other restricted spaces.
Specialised tanks for demanding commercial, industrial, and process applications.
