Friday, 15 July 2022 Knowledge Articles
What is The Difference Between A Detention Tank And A Retention Tank?
Hint: They’re Stormwater Tanks Set Up For Different Purposes
A Promax detention tank and a Promax retention tank are not the same. Sure, they look the same, and indeed, they are both stormwater tanks. But the way they are set up makes them very different. This guide will explain that difference and show you why the words “detention” and retention” are not interchangeable.
In short, a detention tank eases pressure on the public stormwater system infrastructure, and a retention tank eases pressure on public water mains supply system.
Detention Tank:
A detention tank is designed to live its life empty. It detains stormwater for a specified period of time and slowly releases stormwater to the main network. During a rain event, the tank has more water coming into the tank than is exiting the orifice, and the tank fills up. It constantly slowly drains to the stormwater main system, but over a much longer period of time than the rain event, which stops sudden bursts of stormwater runoff, and in turn eases pressure on stormwater networks and reduces the risk of surface flooding in the area.
Stormwater detention tanks take the load off the drainage facilities in your area by releasing manageable amounts of water during downpours. That’s why most New Zealand councils demand owners of new homes install stormwater tanks above or below their property. This helps to preserve the integrity of their existing (and often ageing) stormwater drainage facilities. So, whether or not you need a stormwater detention tank is something that only your local council can answer. If they say you must have one, then the size of the tank comes down to a range of factors, e.g. property size, building structures within your property, or your roof’s surface area. Your council or builder will be able to provide this technical information.
Retention tank:
A retention tank serves quite a different purpose. You could say it is made to serve YOU. A retention tank is just like a detention tank in that it collects stormwater. However, instead of releasing it over time, it retains that water until you need it. People use Promax retention tanks to irrigate the garden, wash the car, fill the pool, hose down the driveway, flush the toilet, and more. You can do many things with all that glorious water you collect and retain for eventual use on your property, and that’s why our plastic retention tanks are increasingly popular.
Because Promax retention tanks effectively give New Zealanders ready access to water, many of our customers are setting up “tank farms”. A tank farm is simply a network of connected tanks that catch and provide as much rainwater as possible. They’re common sights in rural settings or on properties with no town water supply, and they’re based on a straightforward premise: the more tanks you have, the more water you have to use.
We’ve addressed the difference between a detention tank and a retention tank, but you may still have questions about the best product for your specific requirements. We’re here to answer them.
Contact us for further information and advice to help you make the right decision.