Drain maintenance

Environment Canterbury is responsible for the maintenance of a number of drainage schemes across the region. Regular maintenance ensures good channel capacity and efficient land drainage.

Find a drainage scheme.

If you are unsure who is responsible for a particular drain, please get in touch.

Our area supervisors in Kaikōura, Kainga, Tai Tapu, Ashburton and Temuka oversee drain maintenance work so if there is specific maintenance that needs to be done, please let us know. 

Prevention is always better than cure, so the best strategy is to regularly maintain the drainage network before extensive, costly interventions are required.

We always try to contact landowners prior to entering a property. Please call your area supervisor to make sure we have your correct contact details so we can let you know we are planning maintenance on your property.

Responsibilities of the landowner

We need good access to maintain the drains. This includes gates in your boundary, internal fences and fence lines beside drains.

You will also have to ensure fences are an appropriate distance from the top of the drain bank.

Digger on drain bank: fence on one side or the other of the digger.

Trees, hedges and other vegetation must not impede access or the ability of people or machinery to enter the drain.

The Flood Protection and Drainage Bylaw prevents landowners from putting in fences and other structures, and planting trees and other vegetation within 7.5 metres from the top of the drain bank without our written permission.

Vehicles we may need to access the drains include:

  • Utes
  • Tractors
  • Draglines or excavators
  • Spray trucks.

Good maintenance practices

Good management practices to reduce the need for drain maintenance include:

  • Fencing off drains to prevent stock access and bank damage. Permanent or temporary fencing while stock are next to the drain can be used.
  • Minimising nutrient losses from the land, as high nutrient inputs means high weed growth.
  • Planting riparian margins to provide a buffer between the drain and adjacent land use, and to provide shading to the drain.
  • Ensuring good access to the drain for maintenance, including building gateways in fence lines.

If you would like to undertake planting, you will need to contact your area supervisor to ensure this is appropriate on your drain.

Funding and grants may be available for native planting projects.

Erosion and sediment control toolbox

Further information and resources can be found on Environment Canterbury's erosion and sediment control website. 


You must obtain prior written approval to place a culvert or bridge across and Environment Canterbury-managed drain.

You also need to ensure you don’t require a separate resource consent. The structure owner is responsible for ensuring the structure is maintained and kept clear of debris at all times so that it does not restrict flow or cause scour to the bed or banks of the drain.


Stock can cause damage to drains by damaging the banks and causing drain siltation which reduces drain capacity and increases maintenance costs. See policies 4.31 and 4.32 of the Canterbury Land and Water Regional Plan on restricting stock access to waterways.


If it is not possible to install troughs, consider limiting the access for stock drinking.
When choosing access points, avoid the outside of a bend where the water flows faster and the bank is prone to erosion.

River with bend: Gravel pad on inside of bend, with a hot wire fence along the side of the river including between the gravel pad and the river.  

Banks on the inside of bends are less erosion-prone and usually shallower. Avoid positioning access points on steep banks. 

At access points, try setting fences so stock can reach their heads under the fence to drink, but can't get their hooves in the water. Gravel the area that the stock will be standing on. Although this is not advised for large numbers of animals.

Get in touch

For drain maintenance matters, please contact our advisory services team who will put you in touch with one of our depot supervisors.