We all want Otago’s streams, rivers and lakes to have good enough water quality for swimming, gathering food, and to support healthy ecosystems.
Water quality in rivers across Otago show a clear pattern related to land cover and land use. The best water quality is in rivers and streams located in high or mountainous areas with native vegetation, such as the upper catchments of Clutha River/Matau‐Au, Taieri River and Lindis River. There is also good quality water at the outlets from large lakes such as Hawea, Wakatipu and Wanaka. Water quality is generally poorer at sites located on smaller, low-elevation streams that drain pastoral and urban catchments. Find out more about water quality and other information near you by clicking on the "Find your area" tab on the homepage.
We all have a part to play in improving or maintaining the quality of Otago's waterways. ORC carries out monthly State of the Environment (SOE) water quality testing around Otago. SOE monitoring results are based on five years' of data taken when the flow site was at or below median flow. Read the latest results here.
Like all regional councils, ORC provides SOE information to Land Air Water Aoteoroa (LAWA) to add to their national database. Check Otago results here. Note that the LAWA site also has information during summer months about water quality of popular swimming spots in the region. This is collected weekly, and is different from SOE data, which gives a longer-term view of water quality.
People living in Otago can help maintain and improve water quality, whether they live in urban or rural areas, by conserving water, keeping pollution and soil out of waterways, and by protecting river banks and beds. Read more about how you can protect water quality in waterways near you here.
ORC provides rules and regulations about activities that may impact on water quality in the Regional Water Plan, which is currently under review. Below are summaries of some of the rules in the plan that protect water quality.
Discharges and activities that degrade water are prohibited. This means you can’t discharge a contaminant to water the produces a nasty odour, or any obvious oil or grease film, scum or foam into:
- a waterway
- a drain or water race that goes to a waterway
- or any bore, soakhole or effluent pond that is not sealed.
It is also prohibited to discharge any contaminant from an effluent pond of other animal waste collection or storage system, silage pit or composting to a waterway, or onto land within 50m of a waterway, or to saturated land.
If sediment (soil) gets into waterways, it can damage ecosystems by blocking light that allows algae (an important food source) to grow, harming fish gills, filling up important habitats, and stopping fish from seeing well enough to move around or feed.
If you are disturbing land you must put measures in place to control sediment (soil) runoff into waterways, such as putting in a sediment fence. Having no effective sediment control measures is prohibited.
Before starting any activity that disturbs land, you must first check whether runoff can enter a waterway. If there is any chance of this happening you must put control measures in place to stop sediment runoff, such as buffers of grass or other low vegetation, or sediment traps (such as a pit in the ground or cut offs into paddocks).
Sediment runoff from land or any drain (open or tile) leading into waterways, including irrigation races and coastal water, must not result in:
- a conspicuous change in colour or visual clarity, or a plume. For example, you may see a brown plume in otherwise clear water.
- a noticeable increase in local sedimentation.
Stock can only have access to streams, rivers, lakes and Regionally Significant Wetlands if they don’t damage the banks and bed of the waterway or degrade the quality of the water.
- Stock must not:
- Cause slumping, pugging or erosion
- Create a visual change in the colour or clarity of the water
- Damage plants and animals in a Regionally Significant Wetland
- You must not feed out to stock on the bed of the waterway or wetland.
These rules apply to beds of waterways, which includes the banks of the waterway and land that is covered by water when the river is at its fullest flow without overtopping its banks.
You must also ensure that stock do not damage drains and cause sediment to get into downstream water.
Bed disturbance can affect water quality, flood flows, erosion, neighbouring property, vegetation, aquatic ecosystems and habitats. Rules were developed to regulate and reduce these impacts.
Do not undertake work in a waterway during fish spawning periods (check the timing with your local Fish and Game office). Most work in waterways will require resource consent before you begin. However, some work is permitted without a consent providing you meet certain conditions.
Go to pages 2-4 in the Working in Waterways Info Sheet for details about the conditions for different types of bed disturbance activities.
If you’re unsure if you need a consent or not please get in contact with our Consents Team.
Because Otago’s Water Plan does not allow pugging, erosion, or water clarity changes caused by stock crossing through a waterway, building culverts and bridges is encouraged. Well-built crossings help ensure good water quality is maintained.
ORC permits the building of bridges and crossings, provided certain conditions are met. For example, you can build a single-span bridge or a stock crossing without a resource consent provided that:
- it doesn’t cause flooding, impede water flow or movement of bed material
- it doesn’t cause erosion or property damage, and is secure against bed erosion, floodwaters and debris
- animal waste is prevented from entering the water from the structure and adjacent laneway
- any public access along the river bank is maintained.
You’ll also need to meet conditions for any waterway bed disturbance:
- the structure must be legal and the time needed to complete the work within the wetted bed area can’t exceed 10 hours.
- reasonable steps have been taken to minimise the release of sediment to the waterway
- there is no conspicuous plume or change in colour or visual clarity more than 200 metres downstream of the disturbance
- there is no damage to fauna or native flora
- there is no change in the water level or hydrological function of any Regionally Significant Wetland
- the site is left tidy
- no lawful take of water is adversely affected as a result of the activity.
If you can’t comply with these conditions, you’ll need a resource consent before starting the work. Always check with your district or city council to see if you need any consents from them.