In order to fully extend the life of your concrete rain water tank, site preparation is essential:
  • Excavate to the required depth plus 75mm (or more if required to achieve a fall from gutter height) and then back-fill with a layer of 10mm-12mm gravel or screenings. The tank will then be placed directly onto this level base.
  • Ensure the gutter outlet is above the tank inlet.
  • Check delivery access with Ri-Industries.
  • A minimum height clearance of 8 metres is required when unloading.
  • 4.7 metres is needed for the truck to pass under trees and overhead power lines.
  • 4 metres clearance is required between gate posts.
  • Please highlight the position of any underground drains or cables. Trucks will not drive over any concrete or sealed areas without indemnity being signed (including all foundations).
  • Please ensure the unloading site is level.
  • Ri-Industries strongly recommends your tank not be left empty for extended periods.
  • We suggest that the tank is filled with water immediately after placement to at least ground level, until the back-fill soil has compacted.
  • If you have any doubts regarding your installation a site inspection can be arranged.
Excavation, Base Preparation and Backfill
  • Over excavate by 300mm all around to all sides for backfill.
  • Base preparation shall consist of excavating flat uniform surface to a depth of 100mm below the required level and backfilling with 10-12mm gravel for bedding of the tank.
  • Where natural ground is extremely soft, over excavate by 200mm, compact 100mm of 50-75mm ballast into the surface and backfill to the required level with 10-12mm gravel.
  • Complete backfilling with approved granular material such as sand compacted in 150mm layers to 90% maximum dry density in accordance with AS3798.
  • After installation of the tank, backfilling shall be raised evenly around the tank with a maximum backfill height differential of 400mm at any time.
Chain of Responsibility

Ri-Industries takes our involvement in the ‘Chain of Responsibility’ very seriously, ensuring that we comply with the compliance and enforcement (C&E) legislation in relation to potential road safety breaches. We exercise due care and take reasonable steps to prevent breaches of road safety law, and we expect our business partners to do the same. This includes ‘third party transport’ collection of goods from our premises. All transport providers collecting goods from our premises will be required to prove compliance or provide details of the relevant person within the business that we are able to contact for compliance details. This ensures all parties within the ‘Chain of Responsibility’ are protected via the reasonable steps defence measure.

Please also note that:
  • Male brass fittings can be fitted in the tank depending on customer requirements, e.g. for fire fighting purposes.
  • Underground rain water tanks can be installed down to a maximum of 1750 mm below
    the ground but this requires riser pipes to allow access at ground level and a heavy duty concrete cover.
  • Please Note : Ri-Industries advises that all underground tanks are filled at least 50%-75% with water in all chambers to stop floatation.