Stormwater drainage away from the street (without an easement)

Stormwater drainage without an easement

Councils say they need an easement for all properties falling away from the street. But for all single homes, many subdivisions and multi-res projects, there are some much cheaper and faster alternatives.

Scenario 1

Charge as much of the roof to the street as you can (any roof higher than 1.5m above the kerb level). This reduces flow to the rear lot, which is often sufficient justification for council. Ideally you still want gravity fall from the front bondary to the kerb. But if that’s not possible you can use a charged tank or pit on the boundary.

Scenario 2

Often some of all of the roof is too low to charge. In this case, you can mimic the predevelopment or even the natural flow by using a detention tank. This solution also works well if (regardless of roof height), you need a rainwater tank at the rear (say for BASIX, Greenstar or Section J).

Your rainwater tank can accept some of the roof water and then overflow to the detention system.

Scenario 3

In many case there will be a trunk stormwater pipe in the street. If the invert of this pipe is lower than your roof, you can drain directly into it. For larger developments, this usually requires building a new pit at the connection point.

Similar to scenario 1, this removes a lot of water from the property, reducing the flow to the rear neighbour.

Combinations

Most solutions end up being a combination of the one or more of these scenarios. The ultimate goal is to justify the solution by reducing flow to the rear neighbour to an acceptable level.

If you need some help with this and you received this email directly from me, we can run a quick check on these options for you.