Torrent Underground Rainwater Harvesting System - 3400 Litres

• Supplies pressurised harvested rainwater directly to household and outdoor points of use
• Automatic mains water top-up helps maintain continuity of supply during dry periods
• Upgraded from the Cascade system with automatic level monitoring and mains top-up controls
• Calmed inlet and floating intake help maintain cleaner stored water
• B Series stainless steel submersible pump with float switch
• Low-profile underground tank reduces excavation depth
• Strong and durable rotationally moulded polyethylene construction
• 10-year tank warranty

The 3400 Litre Torrent Underground Rainwater Harvesting System provides a complete solution for collecting, storing and reusing rainwater across household, garden and higher-demand applications.

Unlike garden-only rainwater harvesting systems, the Torrent system delivers pressurised harvested water directly from the underground tank to the point of use. This makes it suitable for supplying applications such as toilet flushing, garden irrigation, washdown areas, outside taps and other non-potable water requirements.

With an 3400litre storage capacity, this system is suitable for larger installations where substantial rainwater storage and a reliable day-to-day water supply are required.

An Upgrade from the Cascade Rainwater Harvesting System

The Torrent system incorporates the water quality and pumping features found in the Cascade system, including a B Series stainless steel pump, calmed inlet and floating intake.

It then adds an automatic mains water top-up system and associated controls, making it better suited to applications where a continuous pressurised water supply is required.

When stored rainwater reaches a low level, the system detects this and automatically introduces mains water into the underground tank. This ensures water remains available to the connected points of use while leaving as much tank capacity as possible available for the next rainfall.

This makes the Torrent system particularly suitable where harvested rainwater is being incorporated into the everyday water supply of a property rather than being used solely for occasional garden irrigation.

Typical Applications

The Torrent system can provide harvested rainwater for applications including:

• Toilet flushing
• Garden and landscape irrigation
• Outside taps and hosepipes
• Car and vehicle washing
• Window cleaning
• Patio and driveway washdown
• Greenhouses
• Larger landscaped areas
• Commercial washdown applications

What's Included?

This system combines the 3400 litre underground polyethylene tank with Atlantis' Torrent rainwater harvesting equipment, including:

• 3400 litre polyethylene underground tank
• B Series stainless steel submersible pump
• Float switch
• Patronen Filter
• Calmed inlet
• Rodent guard
• Pump turret
• Pump lifting chain
• Floating intake
• Automatic mains water top-up controller
• Level sensor probe
• Solenoid valve
• Tundish air gap
• Pressure vessel
• Lever ball valve
• Additional overflow

3400 Litre Underground Tank

The 3400 litre underground tank is rotationally moulded from high-strength polyethylene and designed to provide excellent structural strength while retaining a relatively low profile.

Its reduced height can allow a shallower excavation compared with taller underground tanks, helping to reduce the depth of installation required.

The ribbed construction provides additional strength and allows the tank to be installed using a suitable pea-gravel backfill, subject to the manufacturer's installation requirements.

The curved internal profile also helps direct stored water towards the pump so water towards the bottom of the tank can be effectively utilised.

With correct installation and ongoing care, the tank is designed to provide a long service life and is supplied with a 10-year warranty.

B Series Stainless Steel Submersible Pump

The Torrent system uses a B Series stainless steel submersible pump to deliver pressurised harvested rainwater from the underground tank to the connected points of use.

The B Series pump is suitable for rainwater harvesting, domestic water systems, irrigation and water transfer applications.

A float switch helps protect the pump against dry running if the water level within the tank falls too low.

Automatic Mains Water Top-Up Controller

One of the key upgrades over the Cascade system is the automatic mains water top-up controller.

The system monitors the amount of stored rainwater within the tank. If the water level falls too low, it automatically initiates a mains water top-up procedure to maintain the water supply.

Rather than filling the entire tank with mains water, the system introduces sufficient water to maintain operation, helping preserve available storage capacity for future rainfall.

The top-up system includes the necessary control components, including a level sensor probe, solenoid valve and tundish air gap.

Pressure Vessel

The Torrent system incorporates a pressure vessel as part of its pressurised water supply arrangement.

This helps maintain pressure within the system and supports efficient operation when supplying connected points of use.

Patronen Filter

The Patronen Filter, also known as a PF filter, helps remove leaves, grit and other debris from rainwater before it enters the main storage area.

The filter incorporates a stainless steel mesh cartridge within a plastic housing. Its smooth internal construction and level-drop design allow excess debris to pass towards the overflow.

The filter is designed to be self-cleaning, although regular inspection is recommended to maintain effective operation.

Calmed Inlet

The calmed inlet reduces the kinetic energy of incoming rainwater before introducing it into the tank.

This prevents incoming water from excessively disturbing sediment that has settled at the bottom of the tank, helping maintain the quality of the stored rainwater.

Floating Intake

The floating intake draws water from between the surface and bottom of the tank.

This helps prevent floating contaminants from the surface and settled sediment from the base being drawn into the pump, allowing cleaner stored water to pass through the system.

Pump Lifting Chain

The supplied pump lifting chain allows the submersible pump to be raised towards the access opening for easier servicing, inspection and maintenance.

Pump Turret

The pump turret provides the connection between the submersible pump and the pipework supplying the various points of use.

Its flexible plastic construction is designed to accommodate the pressurised water supplied by the pump.

Rodent Guard

The rodent guard helps prevent rodents and larger debris from entering the underground tank through the overflow, reducing the risk of contamination of the stored water.

Important Delivery Information

Please note deliveries to Scotland, Northern Ireland and offshore islands may incur a surcharge. Please contact us for delivery charges to any of these locations.

The delivery will be unloaded from the vehicle by the delivery personnel; however, responsibility then passes to the customer to move the tank into position.