We get asked this question all the time: what’s the difference between a stormwater retention tank and a detention tank?

Basically, a stormwater retention tank is designed to store excess stormwater runoff for use at a later date, to water gardens or flush toilets – this is a great way to recycle grey water. Retention tanks have become a common feature in new housing developments with a green focus, such as Auckland’s Hobsonville Point.

Detention tanks also collect stormwater, but their purpose is to manage the flow of runoff entering streams and rivers from your backyard. With a larger inlet pipe and a smaller outlet, these systems prevent sudden surges downstream by averaging out peak rainfall. Preventing these surges takes pressure off the stormwater network, prevents flooding and limits erosion of sediment in streams and creeks

One thing they do have in common: both detention and retention tanks are primarily underground so they’re sometimes neglected – out of sight, out of mind. But with increasingly unpredictable weather, threatened beaches, coastlines, and rivers, it’s important to maintain stormwater systems and keep both tanks clean of leaves, rubbish and other blockages.

Our team love doing a confined-space entry to clean out tanks! We recommend regular tank maintenance to prevent blockages and issues – being proactive is always better than being reactive in this instance. Contact our friendly team if you have a retention or detention tank that needs maintenance or a clean – we’re happy to help.