The 22000 Litre Underground Water Tank from GRAF is a popular Carat XXL size for agricultural and commercial rainwater harvesting. It holds enough water to keep livestock troughs, washdown hoses and toilet blocks supplied through dry weeks without leaning on the mains.
Because it sits below ground, the tank keeps water cool and dark, which limits algae, and it is safe from frost. The ribbed polyethylene Carat XXL body is far lighter than concrete, so installation is quicker and needs smaller lifting equipment.
Key Features
- 22,000 litre capacity (approx. 4,840 gallons)
- Tough, lightweight GRAF Carat XXL polyethylene construction
- Suitable for rainwater and all non-potable water storage
- Maxi telescopic dome shaft with 150kg pedestrian lid as standard
- Optional 3.5 tonne traffic lid for vehicle areas
- Can be connected to further tanks for extra storage
- 15 year manufacturer warranty and 50 year design life
Planning Your 22000 Litre Underground Water Tank
The 22000 litre underground water tank is about 6.2 metres long. Its long, low body keeps the excavation shallow, which helps on sites with a high water table or where deep digging would be costly.
Specification
- Capacity: 22,000 litres
- Tank type: GRAF Carat XXL
- Tank dimensions: 6230 x 2500 x 2550 mm (L x W x H, before dome shaft)
- Weight: 985 kg
- Colour: Grey / black
- Loading: Pedestrian as standard, vehicle with traffic lid
- Not suitable for drinking water
- Manufacturer: GRAF UK
Optional Extras
- Traffic Telescopic Lid 3.5 Tonne, for driveways, yards and car parks
- Tank Alert EZ High Level Alarm, which gives an audible warning when the water level gets high
Delivery
We deliver free to UK mainland addresses. The tank arrives on a lorry, so you will need a way to offload it on the day. You can download the data sheet, drawing and installation guide from this page.






