Good practice information

Our responsibilities

Whether you live in a town or city there are many things you can do to help protect our waterways, including keeping pollution out of stormwater drains and conserving water as much as possible. It's also important to keep soil from development and construction out of waterways. 

If you are a farmer or rural landuser, follow good practice techniques to reduce the run-off of nutrients such as nitrogen, phosphorus or E.coli into waterways from your property. These contaminants adversely affect the health of waterway ecosystems, as well as posing a threat to human health and restricting recreational and cultural access to lakes, rivers and streams.

Catchment Advisors

ORC's team of Catchment Advisors provide advice and assistance to landowners, catchment groups and other community groups with on-the-ground projects and programmes that contribute to positive environmental outcomes for catchments across Otago.

This includes improving water quality, enhancing our region’s biodiversity - the flora and fauna, promoting sustainable land management practices and initiatives, and to support the development and aspirations of catchment groups.

ORC’s Catchment Advisors have a broad knowledge of farming systems and will support you in your endeavours to be compliant across your property and farming activities.

ORC Catchment Advisors


Each Advisor is responsible for a Freshwater Management Unit (FMU) or rohe (area).

Need a hand with any of the above or simply want to talk about your options...?


Or meet your Catchment Advisor today

Attend one of our Intensive Winter Grazing workshops.


Helpful information

Riparian zones are the land beside a creek, river, lake or wetland. Planting native grasses, sedges, flaxes, shrubs and/or trees in riparian zones can improve the health of Otago’s waterways by filtering nutrients before they reach the water, including nitrogen, phosphorus and bacteria such as E. coli.

Check this guide to see which plants will work best for where you live.

Riparian planting guide for Central Otago

Riparian planting guide for Coastal Otago

Riparian planting guide for East Otago

Riparian planting guide for South and West Otago

Riparian planting guide for Upper Clutha

How long will I need to maintain the plants? 

It can take approximately three years for restoration plants to become established and shade out nearby weeds and long grass. This will of course be dependent on weather patterns and various plant growth rates.  

After three years, plants need less maintenance, but you should still check occasionally for climbing weeds, willow, and gorse invasion.  


How often will I need to conduct maintenance? 

The number of maintenance visits required each year will be dependent on weather patterns (particularly seasonal rainfall) and growing conditions.  

You should expect to conduct maintenance at least twice during the main growing season (spring to autumn). 


Maintenance methods 


Hand release 

For smaller sites hand releasing (cutting and pulling back long grass) may be a practical option. Clear the weeds and long grass around young plants and inside guards before they are smothered.  

Spread the cleared/cut weeds around the base of the seedling as a mulch.  

Sturdy gloves and a hand cutter can help.  

Here’s a good example of a hand cutter: Sharks against weeds 


Brush cutters and line trimmers 

These can be quick and effective as the weeds are left to decompose and create an organic matter layer which holds moisture and improves soil quality over time.  

Simply cut the grass surrounding the plant guard back about 30-40 cm, taking care not to hit the plant or guard. 



Spraying around the guards means that maintenance visits can be left longer and can be particularly effective on large sites. However, native trees and grasses are very susceptible to broad spectrum herbicides such as glyphosate.  

If you choose to use sprays to control grass and weed growth, first contact your chemical supplier or rural services store for advice on appropriate herbicides and methods.  

When spraying near water bodies (rivers, ponds, wetlands), take care not to allow spray or spray drift to make contact with water. Herbicide is toxic to some aquatic life.   

Also, minimise area sprayed in these areas to ensure vegetative cover maintains soil stability. Exposing large areas of soil where there can be flooding can encourage erosion and slips. 

Please keep in mind that herbicide spray-drift from nearby paddocks (that are being developed or resown) also has the potential to impact restoration planting survival. 

Remember to: 

  • Follow the manufacturer's instructions and application rates carefully, including adding recommended surfactants (these often improve effectiveness)  
  • Aim for 0.5 metres of killed vegetation around each seedling  
  • Spray in a S-shaped pattern to avoid overlap i.e. along one row then the opposite way along the next row (spraying in a spiral pattern concentrates the spray)  
  • Take care that the chemicals do not go onto the desirable plant(s) 
  • Spray out from the plant/guard, not towards, to reduce the chance of spray on the plant 
  • Use a nozzle with a narrow fan of spray 
  • Consider a guard around the nozzle to protect your plant from spray. These can be bought or made at home using an old funnel or plastic bottle 
  • Spray on a still day to prevent spray drift coming in contact with yourself or other plants; and 
  • Spray grass while it is shorter, before it becomes long and rank, but while actively growing. 



Please conduct regular checks of your plants during hot and dry conditions. If they begin to show signs of stress (wilting or browning) undertake watering efforts (as much as is practical).  

Watering is best done thoroughly in the morning or evening, but not often (once a week).  

If at any stage you become concerned about plant condition, please contact your catchment advisor. 


Stock exclusion 

Please check the fences and gates surrounding your planting area regularly, especially after flood events.  



Replacement plantings 

Some plants may not survive the first few years. Consider adding plants to fill any gaps.  

You can also add in diversity once your initial plantings are established. 

Some successional species (larger trees) require the shelter of coloniser species (native grasses and shrubs) to survive and are better planted later in your project. 


Pest animal control 

An inspection of pest infestations should be carried out before planting.  

If significant pest sign is evident, seek professional advice regarding suitable pest control options prior to planting. 

When checking your plants, keep an eye out for pest animal signs. Possums, rabbits, and hares can target restoration plantings. Rabbits browse plants, whereas hares can nip the stems off.  

Remember that rabbits are a ‘sustained control’ pest under Otago’s Regional Pest Management Plan and all landowners are required to control feral rabbits on their land – for more detail on the rules and control methods, see our rabbit Pest Hub page. 

You may also live in an area where there are larger pests including feral deer and pigs. 

Ongoing pest control maybe necessary to maintain pest levels. Regular night shooting and trapping near planting sites help to keep in check. 



Chemical ringbarking using a weed-gel or paste has been shown to be successful on willow saplings and small trees (contact your chemical supplier for advice on appropriate herbicides and methods).  

There is also the option of drilling holes in the base of large trees and filling with a chemical herbicide.  

This allows the tree to die standing and provides a perch for native birds that can bring in surrounding native seed.  

If the tree is too big or there is a large infestation, tank or aerial spray can be the most practical way to control willows (of course taking care there’s no spray drift near plantings).   

Mechanical removal of riparian willows (e.g., by using diggers) may require a resource consent – see here for more information. 


Broom and Gorse  

Cut and paste using a weed gel/paste. Large infestation can be sprayed with a knapsack or spray tank (of course being careful there’s no spray drift near plantings).  

In some sites larger woody natives can be planted amongst gorse (which acts as a good nursery plant). 

Over time the natives shade-out the gorse. 

Gorse and broom are subject to the Regional Pest Management Plan as ‘sustained control’ pest species. For more detail on their regulatory status and control methods, see our Pest Hub pages for gorse and broom. 


References and more information: 

Dairy NZ Plant Maintenance Guide 

Sustainable Business Network Plant Maintenance Guidelines 

Taranaki Regional Council Plant Maintenance Guide  

Trees that Count 

How to maintain and monitor your planting projects - video 

For those wanting to set up their own native nursery, you can download this handy DIY Nursery Guide produced by Otago South River Care.

Good farming practices over the winter can help to maintain and improve water quality.

Winter poses particular risks to water quality as any exposed soils can become saturated and prone to muddying from stock, and can then be carried away during rain and storms into waterways. As well as carrying soil that can clog waterways and cause issues for ecosystems, this runoff can also contain phosphorus, nitrogen and E.coli that are a risk to downstream water quality and human and ecosystem health.

Here are some practical tips, videos, links and guides including a management plan to help you. 


Management plan

Download the Winter Grazing plan here.

You can use this paddock plan to assist with documenting the grazing management of winter crop paddocks. It covers environmental good practice and should be completed with the assistance of a Catchment Advisor.
Note: It is not a regulatory document, but you can use it or other templates for the plan you need as part of any application for consent.

Attend one of our Intensive Winter Grazing workshops. 

Tips and Links

There's great work being done to promote best practice over the winter by other groups and organisations from around the region and the country. Here are some useful links:

Some tips from Beef+Lamb NZ for good practice this winter:

    1. Exclude stock from waterways. Create an ungrazed buffer zone between the stock and the waterway. 5 metres is a good starting point, but this should increase with slope and soil instability. 
    2. Leave an ungrazed and uncultivated buffer zone around Critical Source Areas. Critical Source Areas (CSAs) are parts of the paddock that can channel overland flow directly to waterways (e.g. gullies, swales, very wet areas, spring heads, waterway crossings, stock camps and vehicle access routes). Read the Critical Source Areas fact sheet here.
    3. Graze paddocks strategically. On a sloping paddock, fence across the slope and start grazing at the top of the slope. That way, the standing crop acts as a filter. Or, if there is a waterway in the paddock, start grazing at the far end of the paddock.
    4. Create a written paddock plan. Include a paddock map marking waterways, CSA's, fences and grazing direction.
    5. Make breaks “long and narrow”. The crop will be utilised more efficiently by stock. (note: deer might need alternative grazing management)
    6. Back fence. Regularly back fence stock off grazed breaks to help minimise pugging damage and to reduce runoff risk. (note: deer might need alternative grazing management)
    7. Place portable troughs and supplementary feed in a dry part of the paddock well away from any waterways or Critical Source Areas.
    8. Look after your stock. Provide adequate feed, shelter, lying areas and clean fresh drinking water. Doing this will limit stock movement and help reduce damage to crop and soil.
    9. Plant a catch crop. Where soil conditions and farm management allow, consider planting a fast-growing crop in spring such as greenfeed oats. It can make a substantial difference to reducing nitrogen losses.
    10. Plan early. When choosing paddocks for next year’s winter feed crop, think about how you can improve your management of Critical Source Areas and waterways.

We recommend you regularly test the water on your property so you can understand what impact your land use is having on water quality.

Check out this booklet below that tells you more about water testing.

Sampling water quality on your farm


Check out this video that explains water sampling.

Working with your farming neighbours means you can learn from each other and share results. Many catchment groups already exist throughout Otago and some have set up a system for water testing; you could look at joining one, or establish one if there is a need in your area. Give one of our catchment advisors a call on 0800 474 082 to find out more.


Helpful maps

Water quality limits

(schedule 15)


Contaminant threshold limits

(schedule 16)


Nitrogen leaching threshold zones

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