Frequently Asked Questions
Stormwater runoff is rainwater that flows across the ground and does not get absorbed into the soil. It flows into stormwater pipes and streams, and from there into our estuaries and finally out to sea.
Stormwater can cause flooding, and can be harmful to the natural environment by picking up pollutants and carrying them into waterways.
When talking about water, some common terms that are used are
- Surface water
Surface water is what we see in our rivers, lakes, streams, wetlands and estuaries.
Groundwater is the water that exists in aquifers beneath the ground. This is replenished by rainwater that travels through the soil.
Wastewater is the water that goes down drains from inside our house, after we do our washing, or flush the toilet or have a bath.
Stormwater doesn’t go into the sewers. It runs through a separate piped system from that of wastewater or across the ground.
It is a fact that stormwater flows from other properties naturally, either via an overland flow path or via a stream (from high ground to lower lying ground). It is your responsibility to manage stormwater falling and flowing naturally on your site. If you have an issue with any of the following, you should first speak to your neighbour:
- Water flow problems caused by natural ground seepage on private property
- Diverting or blocking the natural flow of water from landscaping, fences and walls or a small trench
- Pool overflows caused by excessive rainfall
Activities like raising the ground level, increasing your impermeable area or blocking a flow path can increase the amount of stormwater flowing to your neighbours site. You will need to stop the activity or cause or you can use a system to prevent the extra stormwater from flowing across your boundary.
Council recommends you talk to your neighbours about any flooding problems you may be experiencing. In many cases, a resolution can be reached that will satisfy everyone’s needs. You may need to consult legal advice, so that any agreement you made with your neighbour is legally enforceable and appropriate for future owners of the land should it be sold on.
If the waterway/drain is on private land, it is the landowner’s responsibility to resolve. If the waterway/drain marks the boundary then the area of it that is within your property is your responsibility.
If the drain is part of the council’s rated and maintained public stormwater network, then it is Council’s responsibility to maintain it.
What are the roles and responsibilities of individuals and Councils in managing the risk of flooding events?
When you buy a property or build a house or business, you can ask your regional council or local council about local flooding issues. If you are building, you can site your home out of any floodable areas, raise the habitable floor levels or make your house using materials better able to withstand floods.
Local councils are responsible for controlling new buildings and the effects of land use to reduce flood risk. They can put special controls on buildings to make the buildings safer from flooding. Councils can also set rules about where buildings can be located, where subdivision can take place, and the effects of land use. In a large flood, councils will coordinate with the emergency services and utility providers to minimise the impact of the flood on people and properties.
Regional councils manage rivers and catchments. They also control land-use activities through the Resource Management Act, as well as regulate large dams under the Building Act.