Why we do this
Stormwater drainage protects our communities, infrastructure and public places from flooding by discharging stormwater and collecting contaminants to minimise adverse effects from rain, runoff and high tides. Stormwater drainage on state highways or floodwaters from rivers or land drainage is managed by NZ Transport Agency (NZTA).
What we do
We run five community stormwater drainage schemes for Dargaville, Baylys, Te Kopuru, Kaiwaka and Mangawhai;
They protect people, houses, private property and public areas from flooding by removing and discharging stormwater, and collecting contaminants in a way that protects our environment and public health; and
Stormwater drainage systems in Glinks Gully, Kelly’s Bay, Pahi, Whakapirau, Tinopai, Paparoa and Matakohe are mostly incorporated into our roads network.
How this benefits the community
Our stormwater drainage activities protect public health and contribute to our social, economic and environmental well-being by:
- protecting people, houses, private property and public areas from flooding by removing and discharging stormwater;
- collecting contaminants in a way that protects our environment;
- complying with resource consent conditions;
- draining water from normal rainfall events;
- processing a 1:5 year rain event for rural/residential areas and a 1:10 year event for industrial areas; and
- managing stormwater in urban areas to retain usability of land.
Dargaville is the main service and visitor centre for the District, and is seen as the gateway to the Kauri Forest. It is a unique town of approximately 4,470 people, positioned on the banks of the Wairoa River.
The Dargaville urban area is serviced by a piped stormwater network and is protected from river flooding by 66 floodgates and various stopbanks. A series of floodwalls was recently installed to protect low-lying areas in the southern-most part of Dargaville exposed to the Wairoa River and the Kaihu River (not included in asset map below). The stopbanks and floodgates located outside the urban area are part of the Raupo Drainage District.
Dargaville Asset Map
Baylys is located on the west coast and experiences seasonal population increase from non-residential owners of holiday homes and visitors.
There is approximately 3.8km of stormwater pipeline in Baylys, and 10m of open drains.
Baylys Township is mainly serviced by a reticulated system consisting of a piped network with manholes and kerbside sumps. Many properties discharge to soakage and open drains.
Baylys asset map
Kaiwaka is a small township on State Highway One built on ridges, with many cafes and speciality shops. It is a stop-off point for many visitors, especially over the summer weekends. The stormwater system is mainly associated with the State Highway and the roads joining it. Kaiwaka is a potential growth area, as identified in the District Plan (Operative in Part).
There is around 320m of stormwater pipeline in Kaiwaka as shown below, and 262m of open drains. Most pipes are 300mm in diameter.
Kaiwaka asset map
The township of Te Kopuru is located on a flat plateau above the Wairoa River. Stormwater is primarily managed through the 4.7km of open drains, discharged to various gullies and then into the river. There is also around 74m of stormwater pipeline in Te Kopuru as shown below:
Te Kopuru asset map
Mangawhai is on the east coast off State Highway One and is a popular weekend retreat for Aucklanders. Mangawhai is expected to experience the highest growth levels of the District, mostly associated with visitors and non-residential owners of holiday homes. Several new subdivisions were created over the past 10 years, and there is potential for more in the future. A particular characteristic of Kaipara is that approximately 64% of ratepayers reside within the District and 36% outside the area. In Mangawhai these figures are 38% within the District and 62% outside the area.
There is approximately 27.7km of stormwater pipeline at Mangawhai and 1.4km of open drains. Most pipes are 300 or 525mm in diameter.
Mangawhai Village asset map
Mangawhai Heads asset map