Stormwater, drainage & stockwater

The Council provides a network of pipelines and open drains that collect, convey and dispose of stormwater.

The Waimakariri District Council has responsibility for the following functions:

  • Urban stormwater
  • Rural drainage: Maps of the Council maintained drains can be viewed on the Drainage areas page
  • Water races: While not a drainage function, the Council also maintains a network of stockwater races throughout much of the rural area, for the purpose of providing stockwater to rural properties.

When talking about water, some common terms that are used include surface water, groundwater, wastewater and stormwater.

  • 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, flush the toilet or have a bath
  • Stormwater runs through a separate piped system from that of wastewater or across the ground - it doesn't end up in the sewer.

Managing stormwater runoff

An extensive system of open drains are in place for the treatment of stormwater in the larger urban areas of Rangiora, Kaiapoi and Pegasus. Smaller networks, with as yet no major treatment facilities, exist in areas such as Oxford, Woodend, Pines, Kairaki  and Waikuku.

Stormwater is discharged, untreated, into streams and rivers. That's why it's so important that it's as clean as possible. If contaminated stormwater pollutes rivers and streams, this can have a negative impact on aquatic life, the natural environment and public health. It can also limit recreational use of waterways.

Maintenance enquiries

Contact Council's Land Drainage Engineer on 0800 965 468.


Emergencies: Contact 111 - Fire Service

Report an issue: Contact Customer Services, phone 0800 965 468 or email

Drainage Advisory Groups

If you would like to be involved in your local community, being a member of a Drainage Advisory Group is a great way of meeting people and making a contribution to your District.

The Council has established a number of drainage and water advisory groups and the membership is reviewed on a three yearly cycle.  Nominations are sought for the following advisory groups:

  • Clarkville Rural Drainage Advisory Group
  • Cust Rural Drainage Advisory Group
  • Central Rural Drainage Advisory Group
  • Coastal Rural Drainage Advisory Group
  • Ohoka Rural Drainage Advisory Group
  • Oxford Rural Drainage Advisory Group
  • Waimakariri Water Race Advisory Group

The rural drainage advisory groups generally cover the rural area of the District where rates exist for maintenance and capital projects. The Water Race Advisory Group is specifically to advise on the water race system in the central part of the District, and works in partnership with Waimakariri Irrigation Ltd.

Application form for apply for an Advisory Group.

Pegasus roadside swales

A swale is a grassed channel that runs along the edges of most roads at Pegasus. Swales collect storm runoff, remove sediment and discharge water to ground. They provide treatment of stormwater and protect groundwater. Read the Pegasus swales information sheet (pdf, 179.6 KB) to find out more.

Tuahiwi Stream Upgrades

Tuahiwi experienced significant flooding in the June 2014 flood event, affecting both roads and private property. The Council has undertaken improvement works in the area. More information about this work can be found here.