
 Home with collar and grate stormwater system


by Jacques Davis - Perth Soakwells
Published 5 September 2015
Copyright 2018 - Perth Soakwells Pty Ltd

You may have passed hundreds of houses but never taken note of the type of connection beneath the downpipes. You may have never noticed the connection beneath the rainwater pipes of your own home! Not only does the connection provide a particular look to your home, it also provides a mechanism of funneling stormwater from your downpipes into your stormwater or soakwells system.

Two types of Connections

Gooseneck / Downpipe adapter

The typical and most common connection is the direct connection system. This also referred to as a gooseneck connection due to the semblance of the extending pipe connecting into the downpipe adapter to a an actual goose's neck. The fitting as mentioned is called a downpipe adapter and can be purchased from any stockist of stormwater or soakwell products.
Downpipe adapters or goosenecks are cheap and very easy to install. There are some benefits of using these fittings in specific situations. The main scenario would be an undercover area that you require to keep dry during the rainy season, such as a patio or alfresco. The gooseneck connection causes no splashing as long as the soakwell has more capacity. 

So what's the problem?

Well, the closed stormwater system presents numerous issues that count against it. Many of these issues are not deal breakers, as our parents and their parents simply ignored the problems they caused or were unaware of them at the time.
  • They are seriously ugly. No , seriously, if you like the look of spaceships or abyss escaping sea creatures, then this is the system for you. Otherwise avoid it. Aesthetically the system is a poor presenter and screams "exposed plumbing entrails" as far as the eye can see. Ofcourse this is an exaggeration as many homeowners accept the look as standard. However, once you see the difference, you would not want to go back to this.
  • Goosenecks are Safety Hazard. Have a look at the photo below. Tell me it does not look like a prop from War of the Worlds. Now look again and imagine kids, the elderly or me at night staring into a bright mobile screen walking this gauntlet. One step slightly too close and Humpty Dumpty comes tumbling down, trying to piece back his shrapnelled phone while slowing the bleedout from a snapped ankle. Okay, I admit this is also probably an exaggeration. But still, they're a clear safety hazard so avoid this system.
  • Backflow. This is a term coined by Perth Soakwells. If you ever hear someone using the term with regard to stormwater, then they probably owe us some form of royalty payment [ mental note: how to trademark a glossary] Backflow is when the soakwell or stormwater tank fills up to the point where the water no longer flows through the piping but rather starts to fill it. As the water fills up the stormwater pipe it eventually reaches the downpipe adapter were some water will start trickle out [ some people actually silicon these, *shakes head*]. The water then builds up past the adapter then works its way up the downpipe. All the while, hydraulic pressure is mounting on the soakwell system itself.
  • Disturbed paving.  If you've been paying attention ( #hybpa ), the above-mentioned pressure placed so much force on the soakwells that sand around the tanks start to churn. The cause the lifting of paving around and near soakwells [not sinking...that is another problem].
  • Ruined eaves and damp. The water continues up the downpipe and finds it self joing with the gutter system water. The gutter system overflows which causes the rain water in turn to overflow into the eaves [ outside ceilings of the house ]. If the gutter system isn't balanced outward the water may run into the wall cavities and affect inner areas of your home.
  • Mould.  As mentioned above gooseneck fittings, in a heavy downpour, may result in water gathering in the eaves and internal ceilings of the home. With painted eaves this will not necessarily be evident until days after when the eaves start to change colour due to mould now growing in the moist areas. Eventually paint stains and peeling paint will require a painter to fix the problem. However, the problem will persist until the stormwater system is corrected.

Collar and Grate System or Open Grill System

The collar and grate system

The collar and grate system or open grill system has been in used for several years, pioneered by Perth Soakwells Pty Ltd. In the heavy storms that occurred a few years ago, Perth Soakwells was the only installer to have ZERO complaints from their clients. Among a number excellent reasons would be the open grate system.
DOWNPIPE ADAPTER not recommend by Perth Soakwells Gooseneck closed fittings used by other installer. Not recommended. offset collar and grate by Perth Soakwells Pty Ltd

What makes the grill system better?

The main subject of this article is the benefits of the grill system over the closed downpipe adapter system. In our experience over the years we have the following to be of benefit to our clients:
  • Breathing.The open system allows air to escape which may be trapped in the system during a flash downpour. This means that the maximum capacity of your soakwells are at your disposal.
  • Overflow. Soakwells will always fill up in a big enough storm due to saturation of surrounding soil. However, the open grate system has the benefit of allowing the excess water to overflow at the grill. The negates any pressure on the stormwater tanks which prevents disturbance to paving.
  • Safe. The grill system does not protrude from the  ground like the gooseneck system. That means fast paced childre, a night walk or the elder will not result hazardous trip accident. Ofcourse downpipes themselves still protrude and have sharp edges, however from the stormwater system side, the risk is significantly reduce.
  • Aesthetically pleasing. YES PLEASE. When you compare a home with a grated system to the closed, it is clearly a more modern, smarter approach to stormwater drainage.


Next time you take a walk out your home or drive down the street. Have a look and compare. If you intend on building a new home, or if you're current home as any of the aforementioned issues, be sure to consider an open grill system. You are welcome to discuss your stormwater and soakwells with us by emailing us at [email protected]
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We look forward to hearing from you!

Stormwater Video - Open Grill Soakwell system

The below video demonstrates water flowing down a collar and grate stormwater system, flowing freeling without pressure into the soakwells.