The Taranaki Regional Council and landowners have embarked on large-scale project to ensure all of Taranaki's streambanks are protected by fences and vegetation.
The Council has drawn up free riparian management plans for more than 95% of ring plain dairy farms, and supplies plants at cost. The map at right shows progress towards total riparian protection, with shades growing progressively darker as protection nears 100% (click on map for large version).
Council Land Management Officers also provide advice and information, on-site when necessary, and can also arrange contractors to carry out the work. They also monitor progress in plan implementation.
Click on the link below for a TVNZ 'Rural Delivery' item on the riparian management programme in Taranaki (select 'Chapter 2' on the Flash player):
TVNZ Rural Delivery - riparian management in Taranaki
Fences keep stock out of waterways, while properly established riparian vegetation filters sediment and pollution, and reduces the speed of run-off, which moderates stream flows and reduces flooding.
Riparian buffers also provide food and shelter for wildlife and corridors for plants and birds. Streamside vegetation also reduces water temperatures and supplies food for aquatic insects that in turn provide food for fish.
This page has information about the importance and benefits of riparian management. Contact the Council's Land Management Section for more information or advice.
Implementation Strategy for Riparian Management (1.3MB)
The importance of riparian management
Waterways are important to the community; historically, culturally, recreationally, and economically. The sustainability of waterways is directly related to how they are managed now, with a view to their future use. It is important that these uses are recognised and the resource carefully managed, to maintain adequate water quality and quantity to fulfil Taranaki's future requirements.
Taranaki has three distinctive patterns of waterway. In the west, short steep-gradient rivers radiate from the mountain across its ringplain to the coast. In the east, long low-gradient rivers wind through deeply-incised, narrow-bottomed valleys in the hill country. Dotted across the ringplain and through the valley bottoms, lakes and swamps occupy small, discontinuous wetlands.
Riparian margins are strips of land adjacent to waterways. They extend from the edge of the floodplain to the waterway itself. The width of a riparian margin depends on the channel's shape, and how it relates to groundwater movement through underlying rock or alluvium. An important component of the riparian margin is its vegetation. The composition of this vegetation greatly influences the functions of the riparian margin.
The issues
Streambank erosion releases sediment and nutrients to waterways. Soil nutrients and fertiliser are carried in on the sediment particles. Valuable assets such as land and buildings are threatened by bank erosion.
Livestock, by grazing on streambanks and entering streams to drink, directly input animal wastes to waterways. The resulting pollution degrades suitability of the water for farm, factory and urban intakes downstream.
The wrong kind of riparian vegetation in the wrong place, for instance tree willows growing in a channel, retards floodwater, inundating farm paddocks and cutting road access. Short-growing vegetation in floodways filters sediment from surface runoff but also keeps it in temporary storage, reducing flood capacity. Drainage of wetlands leads to clearance of swamp vegetation, important for flood storage and also for removal of nutrients like nitrogen from emerging groundwater.
Removal of native riparian vegetation destroys habitats for wildlife, depletes food and shelter for freshwater fisheries, produces fluctuating water temperatures (causing problems for industries which abstract water for cooling purposes), and reduces the aesthetic and amenity values of waterways widely used for recreation by both locals and visitors to the region.
Inadequate fencing of waterways hinders farm management, impedes stock movement, increases stock losses, and necessitates flood-gates.
These issues don't arise everywhere on Taranaki's waterways, but they are sufficiently widespread, that there's a need for better riparian management to reduce their impact on the region's economy and environment.
What is riparian management?
Riparian management is the term that describes how land users look after the margin of a river or a stream, a lakeshore or a swamp. It doesn't entail surveying off a fixed width of land next to a waterway, to create an esplanade reserve for public access.
Riparian management is simply something land users undertake themselves, on land which remains under their private ownership.
There are five basic principles involved in riparian management:
- Fencing the riparian margin.
- Establishing appropriate vegetation.
- Maintaining the vegetation.
- Minimising any adverse effect on waterways from land use in or near the margin.
- Installing protective river control works, if needed.
The Council's riparian management policy
The Taranaki Regional Council considers riparian management to be an effective tool for the promotion of sustainable management of the region's natural and physical resources, which is a statutory responsibility of the Council under the Resource Management Act. The Council offers free advice to landowners with respect to the retirement and planting of riparian margins.
The Council's policy is to encourage good management of riparian margins by landholders, who are in the best position to improve the condition of streams flowing through their farms. Landholders can't achieve pristine water quality, because they're constrained by what enters waterways upstream. However, anything they do helps to improve water quality, enhances wildlife habitat, creates recreational opportunities, and also helps farm production.
What is a riparian plan?
To help the management of riparian zones, the Council's Land Management Officers (LMOs) can prepare a plan for fencing, planting, and maintaining them. This is one of the four types of property plan on offer as part of the Council's Sustainable Land Management Programme.
Preparing the plan doesn't cost anything; it's a free service. One of the Council's LMOs walks over the farm, looking at the streambanks and wetlands, talking about what options could be used to manage them. Next, the LMO produces a draft plan which outlines how the preferred option could be implemented, and what it will cost. At this stage, the plan is fine-tuned, so that it fits grazing management and farm budget.
To implement the plan, the Council will supply seedling plants at cost each winter (their cost is less than $3 each depending on type and size). It's up to landholders to plant them, to install protective fencing, and to undertake any release weeding or pest control. Alternatively a contractor can be arranged to do all of this at an additional cost.
Download the above information in PDF format (273KB)
Does riparian management benefit the environment?
Riparian management has been implemented, to a greater or lesser extent, in many countries besides New Zealand. Its environmental effects have been the subject of much scientific study. Here are some of the findings.
Improving water quality
Dense ground cover on banks (such as ungrazed or laxly grazed pasture) filters sediment out of surface runoff. Sediment levels in waterways are thereby reduced.
Swamp vegetation (such as rush or sedge) on or near streambanks helps remove nutrients, particularly nitrogen, from emerging groundwater before it enters streams.
Where fences deny or restrict stock access, animal dung and urine are eliminated from waterways. Water contamination by organic pollutants, and also by associated pathogens, is minimised.
Tall-growing riparian vegetation (such as trees) minimises daily temperature fluctuations by reducing solar energy input to waterways. Water temperatures are kept cool and less algal growth occurs.
Controlling streambank erosion
Shrubs and trees with extensive fibrous root systems stabilise streambanks. Bank collapse is greatly reduced, and channel migration largely controlled, thereby protecting adjacent farmland and buildings.
Dense vegetation, for instance rank grass or low shrub cover, traps silt and stores it temporarily on banks. Eventually, the build-up is scoured away and transported out to sea by a large flood.
Reducing flood impact
Removal of inappropriate vegetation, like crack willows or blackberry, enables freer passage of water through floodplains. This reduces overbank flooding and siltation on adjacent river terraces.
Enhancing habitat
Restoring riparian vegetation - whether indigenous or exotic - creates habitats for wildlife. Corridors for bird and fish migration can be formed from the mountains to the sea, if continuous riparian vegetation is restored. Food, shelter and seclusion are created for waterfowl, fish, crustaceans and insects.
Does riparian management benefit the farm?
Whatever is spent on it, riparian management gives a return on investment. Here are some of the ways.
Clean water brings fewer blockages in the pipes that draw water for stock, irrigation or dairy sheds, with less wear and tear on pumps and spray-lines.
If cattle are not able to drink directly from the stream then they will not be exposed to liver fluke.
Streambank fences enable easier stock control when mustering, keep sick stock out of streams, and reduce stock deaths by drowning, falling down steep banks, or getting bogged.
Trees on banks, as well as shading and sheltering stock in the adjacent paddock, provide timber for on-farm use if they're silviculturally managed.
Farmers and their families don't just get a farm landscape that's enhanced by trees and shrubs. They also have a better environment for sports such as fishing and shooting, and also for recreational pursuits like boating, swimming or picnics.
Perhaps most importantly, streambank management gives better product quality, together with the marketing advantage of a 'clean green image'. Improved milk grades are obtained where dairy sheds no longer draw water from contaminated streams. On sheep and beef properties, stock are in better health and have faster weight gain when water sources are no longer contaminated by pathogens. Processing plants are increasingly likely to pay a premium for produce from farms demonstrably managed in a way that doesn't damage the environment. In future years it will be easier for them to export it, now that overseas markets are starting to demand evidence that what's being purchased is contaminant-free and environment-friendly.
Does it have benefits off the farm?
Yes. Here are some of the places and people who'll benefit.
Downstream neighbours will have cleaner water, if stock are kept out of watercourses on the farm. Upstream neighbours will have less flooding, if fallen trees and other obstructions are removed. Neighbours on opposite banks will have less bank erosion, if the channel inbetween is kept clear.
Anglers and hunters will have a better chance of catching a fish or shooting a duck, as wildlife habitat improves.
Recreational users - at swimming holes, picnic spots and reserves downstream - will have a more pleasant and healthier environment, once entry of sediment, dissolved chemicals and organic pollutants into the water is minimised.
What does it cost?
No gain without pain - management of streambanks obviously doesn't come cheap.
The single greatest cost is fencing. This can be as great as $16 a metre for a standard post, batten and wire fence - but can also be as little as $2 a metre, if a farmer builds low-cost systems himself.
Alternative water supply can cost more than $1,000 a paddock, if a pump, pipe and trough are installed in each - but less than $100 a paddock by gravity-feeding a trough that can be shared between paddocks by innovative fence design.
Revegetation costs as much as $1,000 a hectare for close-planting of commercial timber species by contract labour - or virtually nothing by waiting for natural regeneration of native shrubs.
A question that is often asked, is 'How much grazing will I lose?'. The answer is 'Less than you think'.
A kilometre of stream, retired to a width of 5 metres on both banks, amounts to 1 hectare of land - about enough to support less than two dairy cows, or a dozen sheep through the year. The pasture that's lost is of moderate quality, due to wetness and weed infestation along the banks.
Where is streambank management feasible?
The banks of streams that flow year-round, through valley bottoms, river terraces, floodplains and wetlands, can be easily managed. They occupy just a small part of farms, are accessible, and can be fenced without inordinate expense or undue disruption to grazing management.
Dowload the above information in PDF format (178KB)
See also our riparian management information sheets for useful and detailed advice on establishing and maintaining riparian margins.
For further advice and information, contact the Taranaki Regional Council Land Management Section:
| Email: | info@trc.govt.nz |
| Phone: | 06 765 7127 |
| Fax: | 06 765 5097 |