Information for landowners with flood water or flood damage on their property

The rain over the two-day period caused widespread surface runoff and disruption to transport routes.  The larger foothill rivers throughout Canterbury all rose through Friday 21 and Saturday 22 July, and have all peaked with water now receding.

There is still extensive surface flooding throughout the region, and the focus over the next few days will be enabling the draining of ponded water as quickly as possible.

For the latest rainfall information visit:

For the latest river flow information visit:

Te Waihora/Lake Ellesmere was opened to the sea on the morning of Tuesday 25 July 2017 and a reduction in lake level will be noticeable over the next couple of days. Click here for more information on how, and why, we open the lake.

Advice for landowners

Flood water

If flood water is ponded on your property, you are able to cut a channel to drain that water back into the river, provided that:

  • the water is redirected back into the waterway within your property
  • the discharge back into the river does not cause flooding on adjacent properties
  • you are not cutting through a stopbank or similar flood protection structure.

If the river has broken through its banks and is still flooding onto your property, please contact us on 0800 324 636 or for advice.

Flood damage

If your property is within a Flood Protection or Drainage Scheme, the River Engineering team is currently assessing damage to our schemes and prioritising repairs.  Please let us know as soon as possible if you see any damage to a scheme asset. If your property is not within a scheme, you may need to undertake the work yourself.

If flooding has caused damage to your land, you can take some immediate actions to prevent further damage.  Work for longer term repairs may require resource consent, please contact us to discuss your options on 0800 324 636 or


If there is debris blocking flows in drains, this may be mechanically removed, however please take care not to cause further damage to drain banks and do not excavate out bank or bed material.

River frontages

River gravels can be pushed up to erosion faces in banks, however you must not cause the river to divert away into other banks.  Take care to minimise the area of disturbance and duration of the work.  Material such as concrete rubble is not suitable to be used for erosion protection.

Trees may be trimmed back if they are blocking or impeding river flows, however this can be dangerous so obtaining specialist arborist advice is recommended.

Emergency provisions of the Resource Management Act (RMA) 1991

The RMA enables certain works to be carried out in order to protect life and property in emergency situations. However, this provision only applies to Local Authorities and Network Utility Operators.

Damage to wastewater systems

Consenting requirements for fixing damaged wastewater systems

If your wastewater system has been damaged, you will need to replace or fix it as soon as possible.

How can you tell if your wastewater system is damaged?
While it can be difficult to spot damage to a wastewater system as tanks and soakage lines are buried, the following may be evidence of a problem with your system:
  • an unusually bad odour
  • low water level in the septic tank (see diagram on final page)
  • overflowing/full septic tank
  • water ponding at the surface near soakage lines or
  • overflowing sewage at your house gully trap
When is a wastewater system considered new replacement verses repair?
Any works to the disposal field or tank system are considered to be substantial changes and the resulting system will be considered new.  The maintenance can include replacement of pipes and fittings.
Do you need to obtain a consent before fixing your wastewater system?
Installing or repairing a wastewater system sometimes requires both a building and resource consent.  Building consents are obtained from your local council e.g. Selwyn District Council; while the resource consent is dealt with by the regional council – Environment Canterbury.
Who can assist with wastewater system repairs or replacements?
A wastewater system designer/installer can assist you in working out what kind of system you require.  Wastewater system designers and installers can also assist you in identifying whether or not you will need a resource and/or building consent to carry out the work.  They can also apply for your consent(s)on your behalf.
To find a suitable local wastewater system designer/installer, we recommend researching on or  Ensure you choose a business with the relevant experience and qualifications to meet your specific needs. If you need further guidance please contact Environment Canterbury Customer Services on  0800 324 636 (0800 EC INFO) or via email at
How do you apply for consent?
You may also apply for the building or resource consent yourself. Application forms can be found at the following websites:
  • Environment Canterbury - applications for resource consents can be found here
  • Application for building consents can be found on your local District/City Council website.  For further information regarding building consents please contact your District/City Council.

Environment Canterbury does not require you to have a resource consent if your wastewater system meets the following conditions;

  1. The discharge volume does not exceed 2 m³ per day; and
  2. The discharge is onto or into a site that is equal to or greater than 4 hectares in area; and
  3. The discharge is not located within an area where residential density exceeds 1.5 dwellings per hectare and the total population is greater than 1000 persons; and
  4. The discharge is not onto or into land:
    • a) where there is an available sewerage network; or
      b) that is contaminated or potentially contaminated; or
      c) that is listed as an archaeological site, or
      d) in circumstances where the discharge would enter any surface waterbody;or
      e) within 20 m of any surface waterbody or the Coastal Marine Area; or
      f) within 50 m of a bore used for water abstraction; or
      g) within a Community Drinking-water Protection Zone as set out in Schedule 1; or
      h) where there is, at any time, less than 1 m of vertical separation between the discharge point and groundwater; and
  5. The treatment and disposal system is designed and installed in accordance with Sections 5 and 6 of New Zealand Standard AS/NZS 1547:2012 – On-site Domestic Wastewater Management; and
  6. The treatment and disposal system is operated and maintained in accordance with the system’s design specification for maintenance or, if there is no design specification for maintenance, Section 6.3 of New Zealand Standard AS/NZS 1547:2012 – On-site Domestic Wastewater Management; and
  7. The discharge does not result in wastewater being visible on the ground surface; and
  8. The discharge does not contain any hazardous substance.
  9. The discharge of wastewater is not within the Selwyn/Te Waihora Cultural Landscape/Values Management Area.

Should you require assistance, or have any additional questions, please contact Environment Canterbury Customer Services on  0800 324 636 (0800 EC INFO) or via email at

Farm effluent

In terms of managing dairy effluent whilst the ponds are full, we recommend that you follow industry guidelines.  It is important to have sufficient capacity in effluent ponds and to prepare for rain events by diverting storm water out of the ponds when it rains heavily.  Fonterra and DairyNZ have advisory documentation which can be found on their websites at the links below.

Key points to keep in mind for managing dairy effluent following a flooding event are:

  • Only irrigate effluent as an absolute last resort
  • If you absolutely have to irrigate, discharge it:
    • To the driest possible area
    • As diluted as psossible
    • Do not irrigate anywhere that it could flow over-land into a lake or river