Managing water availability during low flows

Otago has been experiencing drier than normal conditions recently. These are likely to continue for the foreseeable future due to the El Nino event under way in the Pacific Ocean.

To minimise the impact of the expected dry conditions as much as possible, we are encouraging all irrigators to work together to share the available water.

Collaborative sharing will help sustain river flows for longer than would otherwise be the case, and potentially allow irrigators to take water for longer.

Low flow information factsheet (2 MB)

For the latest information on river flows click here.

To subscribe to our Low Flow advisories click here.

How will ORC manage low river flows?

As well as providing information about what is happening with river levels, we are responsible for ensuring the rules regarding water takes are followed so that waterways are managed sustainably.

The ORC low flow management team will meet regularly to assess all available data and to take the decisions necessary to manage river flows sustainably. River flow levels can change reasonably quickly when rain falls. We will respond to changing circumstances and be guided by the following principles:

1. We will actively monitor key waterways and aquifers (including minimum flow sites, scheduled aquifer levels, residual flows and targeted low flow gauging)
2. We will inform community of current flow/level information to enable irrigators to collectively manage the resource
3. We will manage water use to protect the significant ecological values of Otago’swaterways.
4. We will carefully consider the full suite of regulatory tools available to protect significant ecological values of Otago’s waterways.
5. We will not impose flow/level standards stricter than existing minimum and residual flows and aquifer levels (e.g. ‘bounce back’ provisions)
6. Permitted irrigation can commence when flows are at or above relevant minimum flow, residual flow or aquifer levels
7. Stored water is not subject to water restrictions beyond any normal consent conditions. 

How can I help manage water during low flows?

Make sure that you know what the water management conditions of your water take permit require of you, and when you need to act.

We are encouraging all irrigators to work together to share the available water.

ORC staff will be in contact with irrigation groups throughout any low flow event. Low flow advisories summarising the flow situation and advising on any ORC management requirements will be posted below on this page and emailed to any interested parties - subscribe by emailing your request to .

Water shortage directives will be issued if necessary to ensure that our principles are met.

We’re asking irrigators to record the daily amount of water they take to help ensure consistent availability. This information can then be either emailed to or by contacting our Community Liaison and Education team on 0800 474082.

You can also help by reporting any adverse environmental events involving freshwater plants and animals during extra-dry seasonal conditions. Click here

Low flow advisory archives

Friday 5 February 2016

Click here to view the latest low flow advisory

Click here to subscribe to the low flow advisories

Measuring river flow

ORC staffer Nineva Vaitupu works in the Taieri River at Outram during the 2014-15 summer low flow event.

 The Standardised Precipitation Index is a simple measure of drought (and also of very wet conditions) and is based solely on the accumulated precipitation for a given time period. Because droughts vary greatly in duration, it is important to detect and monitor them at a variety of time scales.

What is a Water Shortage Direction?

Water Shortage Directions are issued by regional councils under Section 329 of the Resource Management Act 1991.

Water Shortage Direction

Useful links

Use these links below for more information:

WaterInfo - To monitor the latest river flow information click here, or phone the Flow Phone on 0800 426 463

ORC Weekly river and rainfall reports - To view reports for total weekly rainfalls and average weekly flows, click here.

NIWA soil moisture maps - To view soil moisture maps for New Zealand, click here.

Climate forecasts - To view the NIWA climate forecasts for the next three months, click here.

LAWA - To view LAWA (Land, Air, Water Aotearoa), click here.

Otago Rural Support Trust - The Otago Rural Support Trust can offer assistance to help people get through these tough times, click here to view their website or contact them on 0800 787 254.

Tips and suggestions for coping with and managing dry conditions.

A series of El Nino preparedness factsheets for farmers and lifestyle block owners has been prepared by the Ministry for Primary Industries,  they have also produced a factsheet on managing your financial and mental wellbeing which can be downloaded below. Dairy NZ also has a Dry summer management guide as shown below and ORC low flow factsheet can also be downloaded below.

Preparing for El Nino Prepareing for El Nino Lifestyle blocks

Preparing for El Nino (518 KB)

Get prepared for El Nino - Lifestyle Blocks (922 KB)

Managing financial and mental wellbeing Dairy NZ dry summer guide

Managing your financial and mental wellbeing (1 MB)

Dairy NZ’s dry summer management guide (317 KB)

ORC Low Flow factsheet

Otago Regional Council low flow factsheet (2 MB)


What does the predicted El Niño weather event mean for Otago?

The El Niño event underway in the tropical Pacific is expected to peak in the summer of 2015/16.

New Zealand tends to experience stronger or more frequent winds from the west in an El Niño summer, typically leading to drought in east coast areas and more rain in the west.  This means that there is a higher risk of continued dry conditions, particularly in North and Central Otago and the Maniototo.

Seasonal outlook

The NIWA seasonal weather outlook summarised for Otago (November 2015 to January 2016) is:

Eastern Otago: Rainfall and soil moisture levels are about equally likely to be normal or below normal. Soil moisture levels and river flows are most likely to be below average.

Western Otago: Rainfall and soil moisture levels are likely to be normal or above. River flows are about equally likely to be normal to above normal.

Go to NIWA's seasonal climate outlook from November 2015 to January 2016 for the full seasonal weather outlook.

Toxic algae

Cyanobacteria are a group of photosynthetic bacteria sometimes called blue-green algae.

Toxic algae occur in rivers and lakes throughout Otago, including waterways with very good quality water. It is more likely to be present during low river flows because of the favourable conditions, including warm temperatures, ample sunlight, and low or stable river flows.

Ingestion of toxic algae by dogs can be fatal. Find out what to watch out for here.

Environmental reporting

Click here to use the 2015 Environmental Observations report form to report adverse environmental events involving freshwater plants and animals during extra-dry seasonal conditions.


Otago Regional Council

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Dunedin 9054

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