Residential Stormwater Detention
What is stormwater detention?
Stormwater detention refers to storing or detaining rainwater for short periods. The stored water is released at a reduced rate once the rainfall intensity reduces or stops.
Note: This is different to collecting rainwater for later use in irrigating gardens or other uses, where the water is held in tanks for extended periods.
Why do we need stormwater detention?
Urban development can increase the proportion of stormwater runoff and therefore increase stormwater flows. This could worsen existing flooding problems because Council stormwater systems are generally designed to handle stormwater from existing developments only.
When is storage required?
Stormwater detention storage is required when the proportion of building roof, driveways or other hard surfaced areas exceeds approximately 50% of the total site.
Where do I put this storage?
Above ground tanks can be designed to complement the form of existing or new buildings. Below ground tanks are also available for storage while other options include landscaped garden areas that allow for short term ponding of water during heavy rainfall.
What volume of storage do I need?
Find out how much stormwater detention you require (if any), have the following information ready (in square metres) and download our calculator from the related documents below.
Please note that this calculator is
- Total property area
- Proposed roof area of buildings
- Area of proposed driveway and other hard surface areas including patios or decks