Have You Experienced Flooding? You May Need A Detention Tank

If you are building a new home, there may be several requirements that you’ll need to meet. One of these requirements might be stormwater management, which will require the use of a detention tank. If you are experiencing flooding, a detention tank may also be your answer.

What are detention tanks?
Detention tanks are large tanks that are normally installed below the surface and used to suppress the effects of heavy rainfall, or stormwater. They work by temporarily storing the rainwater runoff during rainfall and slowly release the water through a small diameter orifice into the public storm water system. This reduces the peak flows of stormwater and reduced the chance of flooding due to an overloaded stormwater system.

Detention tanks are usually required in areas where storm water flooding risks are high. This is especially true in many areas in Auckland, with the current increase in population and housing. Generally speaking, if you are adding roof space by extending or building a new home in areas where stormwater systems have not been renewed, you will most likely require a detention tank.

Detention tanks can also be useful for managing stormwater onsite. This is most common used in combination with soak holes. This systems gives the ground enough time to soak excess water which prevents any surface or ground related flooding.

How big does my detention tank need to be?
In Auckland, a rule is based on several conditions such as the “storm of the 100 years” principle, which would be to allow for 100 liters per 1 square metre of roof surface area. Depending on detention requirement, the outlet orifice can range between 10mm-40mm. Some further information can be found regarding size of detention tank from Auckland Council here.

We at Rotational Plastics can help you get the detention tank you need for your home. See our large range of plastic detention tanks or call us on 0800 768 284 today!

If you are looking for a Drainlayer to install any of our tanks, please don’t hesitate to call Drainage NZ for a free quote.

Guide To Choosing Marine Storage Boxes

All boats have organization and built-in storage features. But in reality, no matter how big the boat, there never seems to be enough stowage options available. Every nook easily fills up with fishing gear, watersports equipment, boating accessories and random stuff brought on trips.

Additional storage is often required to de-clutter and optimise boat space. Here’s where marine storage boxes come in handy.  These versatile storage items will keep your stuff out of the elements but still within easy reach.

Marine storage boxes provide a safe and secure place for all of your boating essentials and tools. Since they are water-tight, they are especially useful for keeping manuals, reference cards, extra cash or your stash of sandpapers dry as well as easily accessible. These versatile boxes can also be used for keeping your catch of the day fresh or your party drinks cold, or for safekeeping small stuff that tend to get lost or broken. Of course, they will also keep your snacks, blankets, towels and gadgets dry even in extreme boating or weather conditions. You can also use these storage boxes as extra seats or step stools since they are built to hold a lot of weight and can endure knocks.

Now, not all marine storage boxes are built the same. So we’re giving you some tips on choosing the right on for your boat.


Standard boat storage boxes are usually made of fiberglass, which makes them extremely strong and able to hold well even in severe conditions. There are a number of problems for this type though, and one is that these aren’t one-piece containers. They have seams where leaks could occur. Fiberglass is labour intensive to manufacture and requires a special barrier to prevent corrosion, which make it expensive.

Other marine storage boxes are made of polyethylene, which is a comparably strong but relatively cheaper material. withstThese are usually seamless one-piece containers that are far less likely to leak. The Tyson Handyman Storage Boxes, in particular, use a special kind of polyethylene which is UV stabilized to withstand UV degradation. This makes them weatherproof, which is perfect for marine applications. They have been tested to withstand knocks and impacts without breaking.

Both fiberglass and polyethylene storage boxes have a watertight seal as well as stainless steel latches and hinges for waterproofing.


Yes, boat storage boxes come in shapes other than the usual rectangle. There are triangular storage boxes for utilizing those odd nooks when space is really tight. Many say these are easier to install and more versatile. But if you need a good amount of secure storage, we recommend the regular shaped storage. Rectangle boxes butt up against each other nicely.


The size totally depends on what you’re planning to stow.  There are definitely a wide range of options where size matters. Apart from size, boat storage boxes can have different configurations. Some have trays inside for easy organizing, double lids for easy access, inbuilt drinks holder or other features that make life onboard a breeze.

To learn more about your marine storage box options, see our range of marine storage boxes here or contact us on 0800 768 284.

Creative Uses For Plastic Bins

Plastic bins are excellent for storage, for moving or for sorting items, parts or pieces. But with a bit of creativity, plastic storage bins can be used for so much more. Here are some interesting and creative uses for storage bins we have come across:

Small Pond
Using a plastic container as a waterproof pool, this person made a small pond in their yard by digging a hole in the ground, placing the bin in it, filling it with water and decorating it with plants, tiles and decorative stones. We think this is quite clever and a creative, cost effective way to create
a feature in your garden.

Floating Drink Cooler
A great item for summer, this is one cool way to have your drinks in the sun. A floating drinks cooler, this plastic bin floats on the water by use of pool noodles tied around the edge, close at hand for when you need a refreshment. This is a simple and easy to make piece of equipment, and will make your time in the pool that much more enjoyable.

Pet House
If you need somewhere to house your furry friends, a plastic bin could do the trick. A bit of DIY to create openings, installation of a mesh and any other features you with to throw in, and you could have a cheap and fun home for your rabbits, mice, guinea pigs or other pet.

Cat Litter Boxes
Loose kitty litter is a common problem amongst cat owners and one that is solved by this great solution. By getting a plastic bin and cutting a large enough hole in the lid for your cat to climb in and out, you create a contained kitty litter box which will ensure all the litter stays inside. When it’s time to change the litter, you simple remove the lid, fill new litter and replace it.

Yarn Organiser
For all the knitters, sewers and craft lovers, this is a great solution to keeping your yarn in check. By poking a few small holes into the lid of your plastic bin, you will have a new yarn box which you can organise to suit your needs, be it color, style or any other way that suits. The yarn you need will always be ready and untangled


These are just some examples of how you can be creative with our plastic bins, there are many more undiscovered uses for them that we will leave up to you. Head over to our range on our website to get yours and let’s see what you can do with them!

Are You Flooding? Get A Detention Tank!

If you are living in an area that is constantly being developed or re-developed, chances are you deal with street floods whenever there’s a storm or heavy rainfall. The reason for this is that urban development increases “hard surface” which doesn’t absorb water, unlike soil and grass. Examples of hard surfaces are concrete paths, roofs and paved areas.

Intense rainfall dumps large amounts of water on your property. And since stormwater is no longer being absorbed into the land, there is increased run-off into local stormwater systems. As more dwellings are built, the public infrastructure becomes considerably undersized.

A good solution to ease the pressure on existing infrastructure is installing detention tanks. In fact, this is now a mandatory requirement for new homes as well as extensions. Having a detention tank plumbed into your existing drainage system is also encouraged as it makes stormwater run-off more manageable.

What is a detention tank?

A detention tank stores water collected from your hard surfaces during a rainfall event, then releases the water into the public drains at a slow, controlled rate. The slow release of the stormwater reduces peak stormwater flows and, in turn, reduces the impact on stormwater systems as well as the chance of flooding.

Detention tanks are different from rainwater retention tanks. A retention tank is a normal water tank which simply harvests rainwater and “retains” it for domestic use. Most retention tanks can only hold so much water. In case of intense rainfall, they can quickly fill up and the water overflows into the local drains in an uncontrolled manner.

On the other hand, a detention tank is intended to remain empty to make space for stormwater runoff during periods of rainfall.

It should also be noted that stormwater is different from rainwater.

Rainwater refers to rain that falls on roofs, while stormwater refers to rain that falls on hardstand surfaces other than roofs. The distinction lies in the quality of the water. Research has proven that although rainwater harvested from a roof may contain dust or debris, the debris is likely to be organic and the quality of the water makes it excellent for use in the household. Meanwhile, stormwater may have potential contaminants such as oil drops, pet droppings and rubbish.

Detention tanks may be installed above or underground.

Detention tank solutions

A detention tank is designed to empty the required amount of water at the required rate.

How big your detention tank should be depends on the specifications required by your local council. The council will also specify the size of the orifice and the flow rate of water from your detention tank. In most cases, a certain percentage of your roof or ground area will be specified for use in harvesting stormwater.

Aside from the specified size and capacity, these are the things to consider when selecting a detention tank for your property:

  • Space and budget considerations
  • Aesthetics
  • Ease of installation
  • Maintenance

If you need help choosing the right type of detention tank, contact us on 0800 768 284 and we’ll talk you through the specification and building process.

Mould Your Own Ideas

Do you have an idea that you think would make a great plastic product? Many people do but think that turning it into reality is unrealistic. However, this is far from the truth, and producing a product from an idea is not as hard as it may seem.

When it comes to custom rotational plastic moulding, no idea is too far fetched. Once you have an idea for an item or product, the technicalities will need to be worked out. How it will be constructed, the size and scale, will it be once piece or several etc. The mould for the item will also need to be made, so that it can be constructed.

If you are unsure of how realistic your design is, or are unsure of the technical aspecs of the design, we are able to work with you on the design to make it viable. There are certain conditions that need to be met, such as wall thicknesses, to ensure that the item will be strong enough, hold it’s shape and withstand the circumstances it’s to be used in.

Once we have all these points worked out, it’s time to make the product. This is where the equipment is set up to make your specific item, which includes the mould. Once the equipment has been set up, it is very easy and often much more economically efficient to make a large quantity of the item, since the setup has already been done.

Now the actual plastic moulding takes place. This usually consists of four main stages.

  1. A measured amount of polymer (plastic, usually in powder form) is loaded into the mould.
  2. The mould is then headted in an oven while rotating, which melts the polymer and adheres it to the walls of the mould. The mould is rotated through two or more axes and at different speeds to avoid an accumulation of polymer powder in one spot. The amount of time the mould is in the oven is critical, as too long and it can impact the strength of the product, due to the polymer degrading, and too little time in the oven means the polymer will not melt completely which can result in large bubbles in the polymer.
  3. Now the mould will be cooled, usually by use of a fan. This part can take some time, as it needs to cool enough so that the polymer solidifies and sets, and it’s cool enough to be handled safely by the operator. Upon cooling, the part will shrink and come away from the mould, making removal easy.
  4. Removal of the part from the mould.

At this point your product is a reality which you can see, hold, and use. The creation process is not as complex as it may seem, it just takes knowledge, experience and the right equipment to produce the results. If you have a product you would like to see realised, get in contact with us today to discuss your idea!

What Are Our Most Popular Products?

When you sell such a wide variety of products like we do at Rotational Plastics, naturally the question comes up. What is the most popular product in our range? We had a look at our statistics to see the answer.

It turns out that tanks are the most popular category of product on our website. People love our plastic tanks, whether for retention, storage or even spray water tanks. But why are tanks so popular?

Many people are looking to move off the grid, and water is one of the main utilities which you don’t have control over unless you collect your own. With a water tank, you can collect and store your own water. This is also an excellent option in more rural areas where mains water supply is not available.

What does our range of tanks include?

Above ground tanks – Above ground tanks are increasingly common across New Zealand because they are a cost effective way to collect and store water. The advantage of these tanks are that installation and maintenance is both cheap and easy, since the tank is easy to place and get to. There is no excavation needed. When maintenance is needed, which involves emptying and cleaning the inside, this is much easier with an above ground tank – simply hose down the inside and tilt the tank to drain the water.

Below ground/underground tanks – These tanks are installed either partially or completely under the soil, and are another popular option. However, they are a more permanent solution, as they require excavation to install them. The benefit is that they don’t take up any space above ground, so you still have a backyard to enjoy. They are most often installed during the building process of the home, minimising installation costs and inconvenience once the home is built. Underground tanks need to be reinforced in order to handle a long life underground.

Mobile home water tanks – These are the perfect solution if you need to storage water in your mobile home. Also good for boats, these plastic tanks won’t corrode and will ensure that your water stays clean and protected. These come in a range of shapes and sizes to suit a wide range of applications.

Spray water tanks – These are tanks with pressure washing systems. They come in a range of sizes and shapes and can be used for many applications.

Check out our website now for a wide range of plastic water tanks in all shapes and sizes!

All About Detention tanks

You maybe have been browsing our website and no doubt came across our detention tank range. There are tanks in all shapes and sizes. But what are these tanks actually for?

Detention tanks, which are sometimes called retention tanks (though this is incorrect), are generally used when storm water system in not adequate enough to deal with the job of extracting water. The detention tanks works to slow down the rain that comes off your roofs and goes into the stormwater system, to prevent overflowing. This is generally an issue in older areas where a lot of new houses are being built and a lot of strain is being put on the stormwater system. Where this is an issue, councils often require the use of detention tanks.

What happens if you have a retention tank is instead of the water flow straight into the stormwater, it comes off the roof and other areas and into the detention tank, then drains slowing through the orifice outlet into the stormwater system. The tank and orifice will be specified to drain at a certain rate, depending on what the stormwater can handle. This can take hours depending on the flow rate. The area your building is in will have specific requirements for this.

Detention tanks can be stand alone units, but often times there are combined with a retention tank. The retention tank stores water for when you need it, in contrast to the detention tank. So how this works will be if you use a 3000 litre tank, the bottom 2000 litres will be used to store your water, and the top 1000 litres for detention.

So what do you need to look for when buying a detention tank? The first thing you’ll need to look at are the council requirements in your area for water flow. You need a tank that will meet these requirements, which will determine the size your orifice you need to select. If you are going to going to be getting a combination retention tank, then you also need to take into account how much water you need for storage. You also have the choice of above ground or below ground.

We have a wide range of detention tanks on our website in all kinds of configurations, sizes and shapes. Have a look through our range and contact us if you need assistance selecting a tank for your home!




All About Commercial Plastics

If you are in the market for commercial plastics have you been tempted to buy overseas? The international marketplace can provide some very attractive options, however do you really know what you’re getting when you purchase overseas? What types of things do you need to look out for?

Suppliers in developing countries are keen to win new business and prove their product is worthy of your hard earned cash. They want the turnover, they want to join the market and expand their business – just like everyone else. There is nothing to say that an overseas supplier could not make a perfectly acceptable item but what are the risks associated with purchasing your commercial plastics overseas?

Risk Factors:

  • Cheaper quality: Each country will have its own regulations for manufacture of products. When you buy overseas often the perceived quality is of a much lower standard than you would receive from a New Zealand based supplier who must follow the guidelines as set out by New Zealand law. Purchasing your stock from an overseas supplier may look good on your bottom line, but what guarantees do you have that the items your purchase from them will be fit for use in New Zealand?
  • Language barrier: Even with the best understanding of another language – things can get lost in translation. If the supplier does not understand your specifications for your product, they may be reticent to ask questions in order to save face or hold their pride. This can lead to mistakes which are not easily rectified and can be very costly.
  • Intellectual property protection: When you choose to give your product idea to a New Zealand supplier for manufacture you can rest assured that you have full protection of your Intellectual Property. There are stringent penalties – including time in jail – if your idea is copied. Overseas suppliers however do not fall under New Zealand law and your ideas can (and will) be copied.
  • Delays: Yes, delays can happen in New Zealand as well as overseas. However, when you purchase goods for manufacture in New Zealand you can have control over the chain of suppliers needed to manufacture your goods. When you purchase from a company internationally you are at their mercy and have to trust them implicitly to have all items needed onsite to complete your purchase. If there are delays in the manufacturing process then there can also be shipping delays getting your items from the country of manufacture to New Zealand. Delays can truly hurt your business and your reputation.
  • Extra costs: On top of your manufacturing costs you will also need to pay duty tax on getting your items into New Zealand and shipping fees. Overseas suppliers may not be as honest as you might think and extra costs could slip into your final account. Make sure you know what you are getting into before giving the OK to manufacture.
  • Scammers: Do your research. Talk to your competitors in New Zealand and find out who they have had good dealings with and who to avoid.

So with all this negative talk about buying overseas – why buy commercial plastic from a New Zealand based manufacturer?

Rotational Plastics have been leading manufacturers of rotational moulded commercial plastic products in New Zealand for over 30 years. Our plastics stand the test of time and we follow all New Zealand protocols. We can help you with design and manufacture of your products.


Plastic Bins In Shapes And Sizes

Rotational Plastics have solutions for all of your plastic bin needs. No matter what your requirement, we can offer or design innovative bin solutions.

If you are in the building industry, our construction options are built tough to handle the stresses out on the work site. Our range of construction, roading and building plastic products will not let you down. You will never regret buying quality. We have a wide range of products to cover all your needs in the construction field, from road barriers to culverts. We have plastic bins to help you contain your tools and be ready to go on every job. Our toolboxes come in a range of sizes and have varying weight capacities. From a handheld toolbox to a 1.8 metre long toolbox suitable for installing on work vehicles we have one for you.

If you are looking for a storage solution around your home or garden, then our at home solutions are lightweight, durable and extra strong. They are UV stabilised to protect against the harsh New Zealand sun. They will not splinter, rust or rot so are versatile enough to be placed in your garden or used in areas close to the sea. Our plastic is fully recyclable and they all have smooth, non stick easy clean surfaces which can be pressure or steam cleaned to bring them back to looking like new. You could harvest rain water, water the veggie garden, keep the garden free of clutter or even use them to  have some fun. Check out our Porky Pig Toy Boxes if you’re looking for something cute yet functional for your kids to tidy their stuff away in.

Perhaps you run a busy farm and are looking at Rotational Plastics for plastic buckets or troughs to hold feed or water for your animals. We have a large range of feed and water troughs available. These are heavy duty and can withstand day after day use by stock. Our feeding buckets start at 27L capacity and our water troughs hold upto 1600L.

Our commercial plastic solutions are uniquely designed for maximum strength. They are all one piece virtually stress-free mouldings. Like our home and garden plastic options, our commercial solutions have smooth, non-stick easy clean surfaces that are easily pressure or steam washed with detergents. A variety of colour options are available and they can be customised so that your company logos or text can be moulded into them or they can be numbered. We also have hygenic food grade polyethylene (LDPE) plastics available for commercial kitchen use and UV Stabilised plastics are available if you are using our bins and boxes in an outdoor setting.

Boxes, bins, trays, lids, scoops, pallets and trolleys. We have been helping New Zealand businesses keep things sorted, clean and organised for over 30 years. Whether it be 10 boxes or 1000 pallets, see us for your commercial solutions, our team thinks both outside and inside the box.

Spill containment of hazardous substances

Rotational Plastics NZ Ltd are leading manufacturers of rotationally moulded plastic products who have been assisting customers with design & manufacturing solutions for over 25 years.

If the storing or transporting of hazardous substances is part of your day to day activities, then you will have a need for spill pallets, spill containment berms, IBC spill pallets, drum pallets or other secondary containment solutions.

If you are dealing with chemicals, oils, sewage or the like then you will need to consider a form of Spill containment (or different forms of, depending on what you are dealing with) at your workplace.  Accidental spills or overflow, if contained within a spill containment unit let spills be contained within a barrier or drainage system rather than being absorbed at the surface.



Absorbent spill kits have been in place in workplaces for a number of years, but spill containment is considered now to be an eco-friendlier solution. This is mainly because absorbent spill kits have a small capacity, require disposal once used and allow no recycling of the spilled fluid.

Installing spill containment measures prior to a spill can result in significant savings in the event of a spill. Wise people count the cost of possible issues prior to them happening. Instead of paying for a costly clean up, containment measures reduce the impact on the environment and the surrounding area, and may even save some of the resource. Clean up costs can be impacted by numerous factors such as location of the spill, type of oil spilled, surrounding sensitive areas, and local regulations.

Rotational Plastics NZ Ltd have a range of solutions to help you resolve spillage issues. Our trained staff have the experience you need to advise you on the best option for your company. Some of the products on offer at Rotational Plastics are:

  • Bundled IBC’s
  • Drum Spill Pallets
  • Drum Splash Pallets
  • Drum Rack Spill Pallets
  • Spill Bunds
  • Splash Trays
  • Accessories

All of our Spill Containment items provide storage, secondary containment, protection and response to minimize the impact of leaks and spills. There are many applications that our spill containment products can handle such as oils, lubricants, chemicals, diesel and poisons and can be either mobile or fixed.  Our products:

  • Will not splinter or rot
  • Available in a variety of colours and can be numbered and incorporate text and logos
  • Extremely robust and strong
  • UV stabilised
  • Easy to clean

Having the right product in your workplace will help make sure you are in compliance and make your workplace safer. All of our products are made here in New Zealand and are designed and tested to meet specific industry standards.

You can view our full line of Spill Containment items by clicking  >> HERE <<. If you need more information, give us a call on 09 443 5880.