Stormwater on my property
Stormwater collects on the roofs of houses and is removed from the roof through spouting and downpipes. The water should then flow to a Council stormwater system (where available), a private stormwater system or a private soakhole within the property if the soil type is appropriate.
Every homeowner has the obligation to dispose of their stormwater runoff in a way that avoids the likelihood of damage or nuisance to other property. If stormwater runoff from your building is causing damage or nuisance to another property, you will be required to fix the situation and may expose yourself to liability for damages.
This is provided under Clause E1.3.1 of the NZ Building Code E1. It states that if there’s a 10% chance of a big rain event annually, and your building collects or channels that water, you have to get rid of it in a way that avoids the likelihood of damage or nuisance to other property.
It's also illegal to introduce any hazardous substances into any part of the stormwater system. Eventually, that water ends up where wildlife lives (and people swim or fish), so dumping chemicals or oils is illegal and dangerous.
Do I have to accept our neighbours stormwater runoff?
You are only obliged to accept stormwater from uphill properties which would naturally discharge onto your property. This is called “natural servitude.” But if someone changes their land, by adding paving, garden beds, or doing earthworks, they need to control any extra runoff so it doesn’t cause problems for you or anyone else.
