2,000LENDURO 1.0m
Sale price$2,422.50$2,850.00Save $427.50
- incl. GST
Underground tank sale
15% off every standard 1.0m ENDURO. Until 31 October.
Twelve sizes from 2,000 to 10,000 litres, built in the North Island. Pick the volume off your consent and lock in the sale price, or tell us about the site and we will spec it with you.
Save up to $1,275
2,000 to 10,000 litres
Free to site in Auckland Metro, 6,000L and under
Save$1,275
- Stormwater detention and retention
- Built to AS/NZS 4766
- Multiple inlet and outlet ports
- Trafficable with a steel lid and riser
Built in the North Island
10-year pro-rata warranty
Built to AS/NZS 4766
Free to site in Auckland Metro, 6,000L and under
On sale: the 1.0m ENDURO
The 1.0m diameter ENDURO. Twelve sizes, 15% off until 31 October.
The 1.0m ENDURO is our most common underground tank, and it suits most North Island sites: rectangular, set in a straight-sided trench, garden lid as standard. Pick the volume on your consent and lock in the price. Harder ground or an engineered outlet? Super Duty and TankGuard are further down.
Small volume2,000 to 3,500L
2,500LENDURO 1.0m
Sale price$2,805.00$3,300.00Save $495.00
- incl. GST
3,000LENDURO 1.0m
Sale price$3,187.50$3,750.00Save $562.50
- incl. GST
3,500LENDURO 1.0m
Sale price$3,442.50$4,050.00Save $607.50
- incl. GST
Medium volume4,000 to 6,000L
4,000LENDURO 1.0m
Sale price$3,697.50$4,350.00Save $652.50
- incl. GST
4,500LENDURO 1.0m
Sale price$4,037.50$4,750.00Save $712.50
- incl. GST
5,000LENDURO 1.0m
Sale price$4,335.00$5,100.00Save $765.00
- incl. GST
6,000LENDURO 1.0m
Sale price$5,185.00$6,100.00Save $915.00
- incl. GST
Large volume7,000 to 10,000L
7,000LENDURO 1.0m
Sale price$5,652.50$6,650.00Save $997.50
- incl. GST
8,000LENDURO 1.0m
Sale price$6,247.50$7,350.00Save $1,102.50
- incl. GST
9,000LENDURO 1.0m
Sale price$6,715.00$7,900.00Save $1,185.00
- incl. GST
10,000LENDURO 1.0m
Sale price$7,225.00$8,500.00Save $1,275.00
- incl. GST
Sale pricing applies to standard 1.0m ENDURO underground tanks on orders placed by 31 October 2026. Super Duty, TankGuard and 575mm low profile tanks are priced on enquiry. Free delivery to site applies to tanks of 6,000L and under within the Auckland Metro area. Every standard 1.0m ENDURO travels free to your nearest Mainfreight depot; delivery to site elsewhere is quoted by your Promax rep with your order.
Spec it with us
Get the right tank the first time.
Underground tanks are easy to get wrong. The volume comes off your consent, the lid and riser depend on what goes over the top, and the ground decides which build you need. Send us what you have and a Promax specialist comes back with the tank that suits the job, at the sale price if you order by 31 October.
- A Promax specialist checks the volume, lid and build for your site
- Sale pricing held on every order placed by 31 October
- Fast replies, usually within one business day
Promax has been making tanks in New Zealand since 1992.
Delivery
Getting your tank to you.
ENDURO tanks are built in the North Island and delivered across it. Tell us where the tank is going and how big it is, and the delivery that applies lights up.
Applies to you
Free in Auckland Metro
To site, 6,000L and under
Tanks of 6,000L or smaller are delivered free to site anywhere in the Auckland Metro area, which is where most standard ENDURO tanks in this size band go.
Applies to you
Free
To your nearest Mainfreight depot
Every standard 1.0m ENDURO travels free to your nearest Mainfreight depot anywhere in the North Island. Collect it from there, or have your rep take it the last leg.
Applies to you
Quoted with your order
To site, anywhere in the North Island
Your Promax rep arranges delivery to your site and quotes it with your order, so you know the full cost of the tank and the delivery before you commit.
Prefer to collect? Pickup from Promax is available too. South Island site? The 1.2m XPRESS is built in the South Island and is the range to look at first.
The full ENDURO range
Every ENDURO, by build.
The standard 1.0m is on sale. The other builds are priced on enquiry: Super Duty for harder ground, TankGuard where a detention outlet must not block, and the 575mm low profile where you cannot dig deep. Pick the build that suits your site, then the volume your consent calls for.
Choose the build
2,000 to 10,000L
ENDURO 1.0m underground tanks
The standard ENDURO. Rectangular and one metre deep, so the excavation is a straight-sided trench rather than a round hole. The usual choice for a house site with normal ground and room to dig the length.
Best forStandard ground and a straight trench
ShapeRectangular, 1.0 m deep
Volumes2,000 to 10,000L
Choose the volume
Supplied with a garden lid as standard, and cast iron lids are available. For a driveway or footpath the installation guide calls for a steel manhole lid and a Promax adjustable riser, which takes a concrete surround so vehicle loads are carried by the concrete and not the tank.
Built in the North Island. Free to site in Auckland Metro on 6,000L and under, free to your nearest Mainfreight depot elsewhere.
5,000L
Sale price
$5,100.00
$4,335.00
Save $765.00
2,000 to 10,000L
ENDURO Super Duty underground tanks
The ENDURO built heavier, for ground that asks more of a tank. Thicker walls for a high water table, rocky or heavy fill, and more load over the top than a standard backyard install. Same rectangular shape, so the excavation stays a straight-sided trench.
Best forA high water table, rocky or heavy fill
ShapeRectangular, 1.0 m deep
Volumes2,000 to 10,000L
Choose the volume
Where groundwater could lift an empty tank, Super Duty is usually specified alongside the Promax uplift restraint system. Talk to us before you order if the site has a high water table.
Built in the North Island. Extra freight applies to South Island orders.
5,000L
Sale price
$6,900.00
1,000 to 1,500L
ENDURO 575mm low profile underground tanks
For sites where you cannot dig deep. The 575 millimetre body keeps the excavation shallow, which is what you want when there is rock close to the surface, a high water table, or services in the way.
Best forShallow digs and services in the way
ShapeRectangular, 575 mm deep
Volumes1,000 to 1,500L
Choose the volume
Suitable for stormwater retention, stormwater detention and wastewater storage.
Built in the North Island. Extra freight applies to South Island orders.
1,500L
Sale price
Enquire for price
2,000 to 10,000L
ENDURO 1.0m with TankGuard
The standard ENDURO fitted with TankGuard. A detention tank only works if it releases at the rate the design calls for, and TankGuard protects the controlled discharge outlet from blockage. It is patented and available only from Promax.
Best forDetention with outlet blockage protection
ShapeRectangular, 1.0 m deep
Volumes2,000 to 10,000L
Choose the volume
TankGuard is built into the tank rather than fitted afterwards, so this version is quoted rather than priced online.
Built in the North Island. Extra freight applies to South Island orders.
5,000L
Sale price
Enquire for price
2,000 to 10,000L
ENDURO Super Duty with TankGuard
The heavier Super Duty build with TankGuard outlet protection. For demanding ground and a detention system that has to keep releasing at the rate the design calls for.
Best forDemanding ground plus outlet protection
ShapeRectangular, 1.0 m deep
Volumes2,000 to 10,000L
Choose the volume
Usually specified alongside the Promax uplift restraint system where groundwater could lift an empty tank. Quoted rather than priced online.
Built in the North Island. Extra freight applies to South Island orders.
5,000L
Sale price
Enquire for price
When your site needs more
Super Duty and TankGuard.
Not every site is normal ground and a garden lid. Two ENDURO builds cover the harder jobs. Both are priced on enquiry, so tell us about the site and we will quote the right one.
North Island
Super Duty
The ENDURO built heavier. Thicker walls for a high water table, rocky or heavy fill, and more load over the top than a standard backyard install. Same rectangular trench.
- Best for
- High water table, heavy fill, extra load
- Diameters
- 1.0 m
- Volumes
- 2,000 to 10,000L
- Pricing
- On enquiry, not part of the sale
North Island
TankGuard
Outlet blockage protection for detention. A detention tank only works if it releases at the design rate; TankGuard keeps the controlled outlet clear. Patented, Promax only.
- Best for
- Detention outlets that must keep releasing
- Available on
- 1.0 m ENDURO and Super Duty
- Volumes
- 2,000 to 10,000L
- Pricing
- On enquiry, not part of the sale
Plan the install
Before the digger arrives.
The tools and documents the drainlayer and the council will ask for, in one place.
Specification tool
Match the consent volume to a tank, lid and riser Installation guide
Excavation, bedding, backfill and lid detail Detention calculator
Pre and post development flows for your consent Orifice sizing tool
Staged volume and outlet sizing Lead times
Current build and dispatch times Find an installer
Registered drainlayers across the North Island
Match the consent volume to a tank, lid and riser Installation guide
Excavation, bedding, backfill and lid detail Detention calculator
Pre and post development flows for your consent Orifice sizing tool
Staged volume and outlet sizing Lead times
Current build and dispatch times Find an installer
Registered drainlayers across the North Island
FAQ
Before you order.
How does the sale price work?
Every standard 1.0m ENDURO underground tank is priced 15% below retail on orders placed by 31 October 2026. The price on this page is the sale price, with the retail price shown alongside so you can see the saving.
Lock in a size and your Promax rep confirms the tank at the sale price, plus delivery to site if you want it. Super Duty, TankGuard and 575mm low profile tanks are priced on enquiry and are not part of the sale.
How does delivery work?
Tanks of 6,000L or smaller are delivered free to site anywhere in the Auckland Metro area. Every standard 1.0m ENDURO travels free to your nearest Mainfreight depot in the North Island. Anywhere else in the North Island, your Promax rep arranges delivery to your site and quotes it with your order. Pickup from Promax is also available.
South Island site? See the XPRESS range first.
Can I get an ENDURO in the South Island?
Yes, but start with the XPRESS. ENDURO is built in the North Island, so South Island freight is quoted with the order. The 1.2m XPRESS is built in the South Island, covers 2,000 to 10,000 litres, and is usually the shorter trip. See the XPRESS range.
What size do I need?
The volume is not ours to pick. It comes from your resource consent, or from the engineer who did the stormwater design, and it is usually written in litres or cubic metres.
If you have that number, go straight to the sale sizes and pick it. If you do not have it yet, send us what you do have and we will tell you what is needed to size it.
Can I put it under the driveway?
Only with the right lid and riser. The standard polyethylene lid supplied with the tank is for garden areas. For a pedestrian or trafficable area the installation guide calls for a steel manhole lid and a Promax adjustable riser, which takes a concrete surround so vehicle loads are carried by the concrete and not the tank.
Tell us what goes over the top, whether that is foot traffic, cars or heavy vehicles, and we will confirm the right lid and riser to order with the tank.
What stops it floating in wet ground?
An empty tank in saturated ground wants to lift. Uplift restraint kits hold it down, and they are sized to the tank: on the 1.0 m ENDURO that is one kit per 1,000 litres, so a 5,000 litre tank takes five.
Stated burial depths in the installation guide assume dry ground with no hydraulic loads, so if groundwater is a known issue on your site, say so when you enquire and it goes into the spec.
When should I ask about Super Duty?
When the site has a high water table, rocky or heavy soil, flotation risk, or more load over the top than a standard install. It runs 2,000 to 10,000 litres, it is priced on enquiry rather than as part of the sale, and it is usually specified alongside an uplift restraint kit. Send your site details and we'll confirm whether it applies.
When is TankGuard relevant?
TankGuard suits stormwater detention projects where protecting the controlled discharge outlet from blockage is part of the design. It is built as a separate version of the tank rather than fitted afterwards, so ask us and we will quote the TankGuard version of the size you need.
What warranty do they carry?
Pro-rata, from the date of purchase, per the Promax Warranty Terms and Conditions:
- ENDURO underground tanks: 10 years
- Standard underground tanks: 5 years
The warranty covers the tank. Lids, fittings and inlet and outlet connections are excluded. The tank must be registered on promax.co.nz within 30 days of delivery.
Who installs it?
A drainlayer, working to the Promax Underground Tank Installation Guide that comes with the tank. Excavation, bedding and backfill all matter on an underground tank, and connecting into the drainage is restricted work in New Zealand, so it has to be done by a registered drainlayer.
What should I send you?
Your project location, the application, the required volume, site conditions, consent notes, and any plans or outlet specifications you have. Nothing needs to be finalised before you make contact.
Still got questions? Talk to the team →