A properly designed stormwater drainage system keeps water moving away from your home, business, or construction site, preventing flooding, erosion, and property damage. But getting it right starts with choosing the correct stormwater pipe size.
At Drain Masters Plumbing, we frequently get asked about PVC stormwater pipe sizes, whether for new installations, system upgrades, or troubleshooting drainage problems. Here’s everything you need to know about standard stormwater pipe sizes and when to upgrade your system.
Understanding Stormwater Pipe Sizes
Stormwater pipes come in different sizes, depending on how much water they need to carry. Using the wrong size can lead to overflowing gutters, stormwater drain blockages, and even structural damage.
Common Standard Stormwater Pipe Sizes
In Australia, stormwater pipes are typically measured by their diameter:
- 75mm diameter stormwater pipe – Small residential drainage applications, like garden areas.
- 90mm diameter stormwater pipe – The most common size for residential stormwater drainage, used for downpipes and surface drains.
- 100mm diameter stormwater pipe – Handles higher water volumes, often used for larger residential properties or small commercial buildings.
- 150mm diameter stormwater pipe and above – Required for commercial or industrial drainage, and high-capacity stormwater systems.
Why PVC is the Preferred Choice
Most stormwater pipes are made from PVC because it’s lightweight, durable, corrosion-resistant, and easy to install. PVC pipes are also low-maintenance and less prone to root intrusion compared to older clay or metal pipes.
On the Gold Coast, older clay or metal pipes are still found in some of the region’s older suburbs such as Coombabah, Burleigh Heads, Coolangatta, Ashmore, Benowa, and Carrara. These materials were commonly used in stormwater and sewer systems before PVC became the standard in the the 1980s. Over time, many of these pipes have developed cracks, leaks, or corrosion, making them susceptible to blockages, tree root intrusion, and reduced drainage efficiency.
If your property still relies on clay or metal pipes, upgrading to PVC stormwater pipes can significantly improve drainage performance and longevity. Many homeowners and businesses in older areas are opting for pipe relining or full replacements to prevent costly repairs and ensure their stormwater system meets modern standards.
Common Issues With Existing Stormwater Pipes
Even with the right stormwater pipe size, drainage problems can still occur. If your stormwater system isn’t functioning properly, here are some common culprits:
1. Blocked Stormwater Pipes
Leaves, dirt, and debris can build up in pipes, leading to slow drainage, pooling water, and overflowing gutters. High-pressure jet blasting or CCTV drain inspections can help clear the blockage.
2. Cracked or Collapsed Pipes
Older pipes, especially in homes with concrete or clay stormwater pipes, may crack or collapse due to ground movement, tree roots, or general wear and tear.
3. Undersized Pipes
If your pipes are too small for the volume of water they need to carry, they’ll struggle during heavy rain. This is common in older homes where stormwater drainage wasn’t designed for modern runoff demands.
How to Upgrade or Extend Stormwater Drainage
If your stormwater system isn’t keeping up, upgrading your pipes might be the solution.
1. Check Your Current Pipe Capacity
If your gutters overflow regularly or water pools near your home, your current pipes may be too small or incorrectly installed. Upgrading to a 100mm or 150mm PVC stormwater pipe can improve water flow.
2. Install Additional Drainage Points
Adding extra downpipes, surface drains, or soak wells can prevent stormwater from overwhelming your system.
3. Ensure Correct Pipe Slopes
Stormwater pipes should be laid at the correct gradient to allow water to flow efficiently. A poorly sloped pipe can lead to water buildup and blockages.
Need Help With Your Stormwater System?
At Drain Masters Plumbing, we provide Gold Coast and Tweed Heads residents with expert stormwater drainage solutions, from pipe installations and upgrades to clearing blocked drains. If you’re unsure which PVC stormwater pipe size is right for your home or business, we can assess your property and recommend the best solution.
Call us today or get in touch online for professional stormwater plumbing services with free quotes and upfront pricing.
