400 Litre Underground Water Tank

The 400 Litre Underground Water Tank is a compact, high-strength below-ground storage solution designed for properties with limited space. Manufactured in the UK from virgin MDPE using a tough one-piece mould, this underground tank offers excellent durability, structural integrity and long-term performance. It features an extended neck that can be cut down to suit your installation depth and is fully compatible with standard UK 4" (110mm) drainage pipe fittings, allowing easy connection or linking of multiple tanks.
Perfect for domestic rainwater harvesting, garden irrigation and external pump use, the tank includes a 1" BSP outlet (supplied undrilled) and a 12" access lid for maintenance or fitting a submersible pump. Rotationally moulded for strength and backed by a 10-year warranty, this tank delivers dependable underground water storage in a compact footprint.

Technical Specification

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• Capacity: 400 litres
• Height: 925mm
• Width: 1000mm
• Length: 1240mm
• Weight: 35kg
• Material: MDPE (Medium Density Polyethylene)
• Access: 12" lid
• Outlet: Up to 4" (1" BSP outlet supplied undrilled)
• Inlets/Outlets: Compatible with 4" (110mm) UK pipe fittings
• Construction: One-piece mould, rotationally moulded
• Neck: Extended neck included (cut to required height)
• Warranty: 10 years against manufacturing defects