Onsite Detention Systems

On-Site Detention Systems

When it rains, it’s easy to think the water simply disappears down the drain, but across the Shire, that water all adds up.

As more homes and developments are built, larger roof areas and hard surfaces like driveways mean stormwater runs off faster and in greater volumes. Over time, this places increasing pressure on Council’s drainage systems, particularly during heavy rainfall.

To help manage this, Council’s Technical Services team has been introducing a simple but effective approach for new developments, slowing the flow before it reaches the street.

This is where On-Site Detention systems, or OSDs, come in.

An OSD is designed to temporarily hold rainwater on a property and release it slowly into the drainage system, rather than allowing it to rush in all at once. By doing this across multiple properties, the overall impact on Council’s infrastructure is reduced, helping to prevent localised flooding, erosion and unnecessary strain on drains.

The size of each system is carefully calculated based on the scale of the development, including roof area and hard surfaces and is required in addition to any rainwater tanks on site.

For most standard residential developments, Council determines the minimum OSD requirements as part of the application process. Larger or more complex developments may require a detailed stormwater assessment to ensure the system is appropriately designed.

While it may not be something you see every day, these systems play an important role in protecting local infrastructure and supporting smarter, more sustainable growth across the Bland Shire.