Stormwater networks carry rainwater away from properties and streets through pipes, channels and drainage structures. Public asset information can help identify recorded stormwater infrastructure near a site, but it does not necessarily show every private stormwater connection, soakage system or surface flow path. Understanding what is public and what is private matters before you build, pave or excavate.
Public asset records may identify recorded stormwater pipes, open channels, culverts, manholes, sumps and outfalls near a site. Some authorities also record overland flow paths. They do not necessarily show every private connection or surface flow path, and smaller private laterals are often absent from public mapping.
Public infrastructure and private on-site drainage are different categories. Gutters, downpipes, soak pits and the drains within your boundary are private, even though they discharge to the public network. Some local records combine public and private features on one drawing, but this should not be assumed for every authority.
Available records depend on the local authority and the information it holds. Christchurch City Council, for example, publishes information about stormwater infrastructure and public mapping, and its private drainage plans may include recorded public and private stormwater pipes and certain waterways. Other councils hold stormwater records in different formats or within property files.
A public stormwater asset map is not a flood report, an overland flow assessment or a substitute for utility locating. If you are building near a recorded stormwater asset, the authority may have requirements about clearances and connections. Confirm conditions and obtain appropriate professional advice before building or excavation.
Select your property address to explore the relevant request categories. We identify the authority responsible for stormwater records in your area and show the available options. A usable record is not guaranteed for every property.
Drainage Plans NZ is an independent third-party document sourcing service, not a council or utility. Records vary and availability must be verified for each property. Plans and network maps are not a substitute for on-site locating or before-you-dig procedures.