What’s the difference between a retention and a detention tank?

Some systems are advertised as detention tanks, some as retention tanks, and some do both. The main difference is that a detention tank is a temporary storage solution for stormwater. It will slowly release it into the drainage system, whereas a retention tank will keep it for usage at a later date.

How do you size a detention tank?

Typically, you’ll need a detention tank if your area in New Zealand struggles with stormwater drainage. If that’s the case, your council will likely have advice and guidance for detention tanks. They might set a requirement for a minimum size based on the stormwater rates and how slowly the water should enter the system.

Do stormwater detention tanks smell?

Sometimes tanks can smell. Underground systems don’t have this problem. However, larger tanks that hold on to the water for longer might start to smell due to algae and natural matter inside. It might happen after periods of particularly heavy rainfall, meaning more to store and for longer.

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Water Detention Tanks

- Detention tanks help to control the flow of water to your property, collecting wastewater and stormwater and storing it temporarily. It is then slowly released to prevent flooding, allowing for a more controlled watering and saturation of the soil. ArchiPro features only the best detention tanks from trusted suppliers in New Zealand.

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Detention tanks are becoming increasingly popular in New Zealand as homeowners look for ways to manage storm and wastewater on their properties. You can find detention tanks in all shapes and sizes, which means finding one to fit your property won’t be an issue. They are an important part of a wider range of high-quality rainwater storage solutions that you can find on ArchiPro.

Types of detention tanks

Tanks for storing stormwater come in various sizes and use different materials. Some of the most popular options in New Zealand include:

Slimline tanks

A slimline stormwater detention tank is a popular option for properties in New Zealand that have limited space or want the tank hidden from view.

Round tanks

A round water detention tank is usually made from corrugated steel. They’re strong, durable and can hold large amounts of water, often up to 25,000 litres.

Square tanks

Square tanks have a smaller footprint than other detention tanks. They’re a good choice if you want to store a lot of water in a tight space or install multiple tanks side by side.

Underground tanks

For a tank that’s out of sight, you can install an underground storm vault. These tanks are usually lightweight, made of polyethylene, and need to be installed professionally under your property.

The advantages of high-quality detention tanks

The best detention tanks are built to handle heavy rainfall in New Zealand. They’re large enough capacity to handle most of the storm runoff and their piping and drainage systems are simple but efficient. They seamlessly connect with existing drains for surface runoff and release their contents into the appropriate waterways. Crucially, a high-quality detention tank will be made of a robust material to prevent leaks. The best products will have anticorrosion properties that last for years, giving you a stormwater tank that you can rely on.

How to choose a detention tank that’s right for you

There is a number of factors that will help you choose the right detention tank. First, you’ll need to think about the space you have available for the tank. If you have a large property then this won’t be so much of an issue. The only consideration is where to put it and how it’ll fit in its surroundings. If you are limited on space then you might be tempted by an underground system which doesn’t take any yard space at all. You’ll also need to consider what size tank you need depending on the amount of water you want or need to store. Smaller models like slimline tanks hold around 6,000 - 10,000 litres while larger options can hold upwards of 25,000 litres.