Monthly Archives: August 2016

Retention/Detention tanks in demand

What are retention/detention tanks?

Simply put a detention tank holds the stormwater overflow and slowly releases it into the public system while a retention tanks stores this water and you are able to use it. You can also get a dual purpose tank that does both. The top of the tank is released into the public system and it holds what is left once it reaches a certain level.


Why the call for them?

Auckland as we are all aware is growing fast and strong.  With all the new houses being built and all the new people coming to live in Auckland there is a worry the public system will be overloaded.  So the council is asking home owners to have these tanks installed to help.

Why choose Rotational plastic tanks?

Rotational tanks are the best option as their height is only 1 metre.  Also if site conditions are struggling for falls this is the only tank that will work.  Our tanks can be manufactured to any size as we can add on 500L sections. They are capable of above ground or below ground applications.  They can be used for industrial, agricultural or residential applications.  They are made for easy maintenance. Its key features are:

  • Tanks are pre-assembled and ready to install
  • Have a unique double filter system, and easily removable catch pit filter
  • Modular 1000L increments
  • Ideal for hard to access locations
  • No special bridge requirements
  • Moulded-in inlet and outlet pipe options
  • Multiple inlet and outlet options

Our tank standards are:

  • Designed and engineered to AS/NZS requirements
  • Complies with load testing for light and medium vehicular loading
  • Plastic construction and moulding complies with AS/NZS 4766.2006 specifically for polyethylene storage tanks for water and chemicals

Other information

We suggest having leaf deflectors installed on downpipes to prevent unnecessary buildup of debris in the tanks.  The removable filter bucket is designed to reduce maintenance costs by eliminating the need for regular pumping of silt and debris.  To ensure good operation the tanks should be regularly inspected and cleaned. The envirogental detention tank system has a double filter system, the first is built for large debris at the inlet point so it can easily be removed and cleaned and an easy clean sump is incorporated into the base below the inspection riser to further collect debris.