I've had a landslip on my rural property

FAQs and information for landslips on rural properties

The August 2022 weather event caused numerous landslips to occur in the Nelson Tasman region. We know that many of these landslips have caused damage to property as well as impacted roads and infrastructure.   

We understand that if a landslip has impacted your property that you will have questions about responsibility and how to remediate the land. While each situation needs to be looked at separately as different circumstances may apply, the information below offers some general points to consider for those living in rural areas. There is no one solution to remediating slips so that the land is stable in future events, and possible solutions could involve improving drainage, retaining the bank, or planting. 

This is intended to provide high-level information. We encourage homeowners experiencing land instability issues to seek advice specific to their circumstances.   

Who is responsible? 

Generally speaking, there is a duty on landowners to manage hazards such as landslides occurring on their land, irrespective of whether the hazard is natural, or human made. This can trigger a responsibility for the landowner to manage that hazard, for example, to prevent it from interfering with neighbouring property. 

However, when a hazard arises from natural causes, such as the recent weather event, that responsibility would usually only be triggered if landowners were either aware of the hazard or were negligent or reckless in relation to that hazard prior to the event. This means that a neighbouring landowner may not automatically have an obligation to repair damage to your land caused by a landslip from their property, even if that landslip is impacting your property.  

Your circumstances are unique, so please seek advice and support if you are unsure.  

If the slip originated on Nelson City Council land? 

We are working our way through assessing all damage that has occurred on Council-owned land and prioritising site visits on the basis of severity. We are working to visit all slips, but this process will take some time. If you are concerned, please discuss with your insurer.  

What should I do first? 

Check with your insurance company to see if you have a claim – particularly if your house or infrastructure such as driveways and culverts are affected.  

If you have a claim, your insurer will assess and manage this, including the EQCover portion on behalf of Toka Tū Ake (EQC). EQCover insures your home and some areas of your residential land against loss or damage from natural disasters like landslips and earthquakes. It also insures your residential land (within limits) against storm and flood damage.  

If you have natural disaster damage and are unsure who your private insurer is, or who to notify, call 0800 DAMAGE (326 423).    

Do not touch the slip until it has been assessed by your insurer, as this may affect your claim.  

What if I have a slip on land not covered by insurance?  

For slips on productive land, or where infrastructure is not affected, there are several options for stabilisation and revegetation.  

Contact our Sustainable Land Manager on 03 546 0200 to request a conversation about your property if you require assistance to plan for your remediation. Some support with planting may be available. 

Here are a number of online resources to help.

Resources on native plants

Native planting guide for nelson including planting lists for various ecosystems found in Nelson: 

nelson.govt.nz/assets/Environment/Downloads/living-heritage-nelson-native-plants.pdf (821KB PDF) 

 

Stabilisation charisteristics of native plants – Landcare research summary: 

landcareresearch.co.nz/research/research.asp?theme_id=1&research_id=15 

 

Resources on planting poplars: 

 

For riverbank erosion, you can look at riparian planting or apply for a consent for an engineering solution. 

If you have a slip or slips on your property, what’s the best course of action in the short term to try to stop it continuing to slide? 

The most important thing is to control the water and move it away from the slip.  

  • Note where the water flows while the slip is still wet – diverting water away includes drainage solutions. 
  • Fill in any cracks that have appeared to prevent water entering the soil. 
  • Tracks are particularly vulnerable to slips and it is important to incorporate lots of culverts to divert water in small increments rather than spacing them out and have large water amount of water running off tracks.   
  • Where significant infrastructure is at threat it is best to get expert help as there are a number of strategies that can be used. Contact your insurer or a geotechnical engineer for advice.  

Do I need resource consent for works in or near streams? 

Flood debris including litter, vegetation, and trees can be removed without the need to obtain resource consent. Replanting along the margins of streams is allowed without resource consent as long as no pest plants are planted, and no willow is planted within 5m of the waterbody.  

Please note: earthworks of any height or depth within 10m of the river or stream bank will require resource consent.  

Works in the stream bed/banks or channel to mitigate flooding risk to properties may require resource consent. Experts will need to be engaged to report on what needs to occur to protect property and the stream habitat or stream dynamics. Council may be able to approve temporary measures until the permanent solution is designed and consented. Please contact the duty planner on 03 546 0200 to discuss your situation.  

In situations where it is determined that your works require a resource consent, please include August 2022 weather event remediation works within the description of the activity and provide a report from the expert(s) with your completed resource consent application form. Please identify when works are expected to start so we can have the consent issued in time.  

How long will it take?  

We are aiming to streamline the consent process as much as possible given the circumstances, but we do need to make sure that any work done prevents further sedimentation of our waterways.  

Need more information on how to apply for a resource consent? 

See Council’s website nelson.govt.nz/apply-for-resource-consent , and please phone 03 546 0200 to make an appointment with the duty planner if you need further assistance. 

FAQs  

For slips on farmland, here are some suggested actions:

  • Focus first on restoring infrastructure such as tracks and fences.  
  • Plastic netting can fill gaps in fences for sheep and use electric fences for cattle.  
  • The slip scar cannot be revegetated because normally there is no soil left. Tailings contain the topsoil and will recover quickly from seed material in the tailings and revegetate themselves.  This is the material that can continue to move down the slope.  
  • There is some information that suggests actively re-grassing slips is uneconomic. If you do decide to re-grass slips, then focus on seeding tailings on moderate slopes. Clovers are better able to establish in harsh conditions and are often the first colonisers. Avoid reseeding if sowing conditions are not optimum (approaching dry or cold). 
  • Planting with poplar poles (with covers if grazed by stock) is a good strategy but not directly on the slip scar. Plant in tailings and around the slip edges. 

How can I reduce the likelihood and impact of slips occurring on my property in the future?   

  • Any actions you take may only prevent slipping in average rainstorms. Big events may still cause slips.   
  • Work out the slip-prone areas which are in gullies on steep hills and get advice on poplar/willow pole planting. Soil type is important.  
  • Start planting the eroding gullies first or gullies that threaten infrastructure.  
  • If the area is grazed then include a sleeve for your poplar poles.  
  • Note that these trees stabilise the slopes with roots, and may also remove water from the slope. 
  • Get advice on the type of poplar/willows and how to plant for your conditions and erosion type.  Right now there is a shortage of poles as it is the end of the poplar season (normally supplied when dormant in May). You can cut your own poles yourself and plant. Late in the season it is important to cut poles that are thicker (eg 10 cm in diameter) to improve survival. In autumn you can plant thinner poles. Don’t crack poles from Crack Willow as this is a noxious weed that spreads. Pole survival is reduced if they move easily in the hole, so as the ground dries go and ram the soil in again around them to help them survive.    
  • Space the poles apart with closer distances for erosion-prone areas plant them from 8-12 m apart and alternate them along the side of each gully. There are different planting patterns for different types of erosion, so seek advice if you need it.  
  • Go back and thin the trees once they are established.  
  • If the area is ungrazed you can also plant natives. They are slower growing and will take longer to stabilise the slope. A mix of exotic and native planting can also be used.  
  • Start planting now. It will be 5–10 years before your plantings will be effective at reducing erosion.     

For Te Tauihu the Top of South, what native plants would you recommend planting on landslips in native areas, residential areas or stock-excluded areas that would help to consolidate slips?   

  • It is best to get professional advice on what natives to plant based on your location and the site conditions (dry, wet). Local planting experience is very important and local observation on what has performed well is also important. If you need some help please contact our Sustainable Land Manager on 03 546 0200.  
  • Have a look at these native planting guides prepared for the region. Hawkes Bay Council has put out a native planting list for erosion areas and landcare research has researched root depths and tensile strength of roots on riparian planting. This research shows that cabbage tree and ribbonwood performed well. The roots underground relate well to the biomass above ground.   Exotics generally grow faster but the natives outperform exotics on tensile strength and will stay in place longer.  
  • If where you want to plant on the slip is out in the open you will need to plant first colonisers like natives that thrive in the sun. Within bush you can use second colonisers, and in dry conditions kānuka is a hardy first coloniser.  
  • Many slip faces are not suitable for planting. This is because most of the soil layer that nourishes plants and enables plant roots to establish a hold has been washed away.    
  • Focus on planting around the edges of the slip scarp where topsoil is available.  
  • Where possible focus on managing weeds that can establish on slip sites.    
  • You can use a mixture and tree, grass and flax plantings.   
  • Tutu is a common first coloniser of disturbed ground in the bush. Be aware that it is a poisonous plant to stock and its pollen can contaminate honey.  
  • Wherever possible, nurture and manage river plantings to ensure banks stay intact. In this August 2022 extreme event older plantings held on. Along the rivers, recent riparian plantings were covered in sediment but on removal of the sediment from the 30,000 planted along the Wakapuaka River there has been only a 10% loss.