Otama Rural Water Scheme


Otama scheme tanks


The Otama Rural Water Scheme Bill to transfer ownership of the scheme from the Council to the users of the scheme is presently before Parliament. Details about the process and submissions received by the select committee can be found on Parliament's website.


General information

Scheme Chlorination

Common questions about chlorination

New connections      

Scheme management


Scheme info

The scheme supplies water to 253 connections on 210 farms in the Gore District.

There is 239km of pipeline. The water comes from a bore next to the Mataura River, at the site of the former Pyramid Bridge.

Numerous homes, as well as two schools and a marae, use the water. Historically, the water was untreated as the scheme was originally only for stock water.


Chlorination of scheme 

The Otama Rural Water Scheme committee and Council started chlorinating the scheme's water on 15 May.

The decision to chlorinate was made to ensure users do not get sick from the water. A recent catchment assessment found there was a high risk of microbiological contamination to the scheme’s water source at the Pyramid Well. Chlorination of the scheme will protect against this risk. 

Chlorination is used safely all over the world for around 120 years. It keeps millions of people – including most of New Zealand – safe from waterborne illness. We have been using chlorine in the Gore and Mataura water supplies for many years.


Common questions about chlorination

Why start chlorinating the scheme’s water now?

The Otama Rural Water Scheme Committee and Gore District Council have a responsibility to supply safe and clean drinking water. The Otama scheme was built as a stock water scheme therefore the water is untreated. However, it is the main domestic water supply for a lot of consumers.

Drinking untreated water is a bit like driving without a seatbelt – you may be safe most of the time but when something adverse happens you are completely unprotected.

The Council tests the water source for the scheme, the Pyramid Well, weekly. Most of the time the water is safe to drink although occasionally e-coli is detected. A catchment assessment last year also found there is a very high risk of microbiological contamination to the water source.

Chlorination is considered one of the best way to disinfect the water to protect you, your family and friends.

Why use chlorine?

Chlorine disinfects the water all the way from the intake point to your taps. It also kills small bugs that can get through filtrations systems, such as bacteria and viruses that are difficult to physically remove from water. Other treatment forms, such as UV, only treat everything that goes past it, which means there is a risk of re-infection further down the network.

How much chlorine will be used?

Just enough to keep your water safe. There will be no more than 1mg per litre of water leaving the Pyramid Reservoir. We expect that to drop to about 0.2mg per litre of water at the extremities of the scheme.

How much does it cost?

It will cost about $30,000 to install the chlorination equipment, and between $3000 and $5000 each year to operate. The Otama scheme has sufficient funds to cover these costs and there will be no increase in charges to scheme consumers.

Could the chlorine affect my health?

No, not at the quantities we will be using. Chlorine has been used safely all over the world for around 120 years. It keeps millions of people – including most of New Zealand – safe from waterborne illness. We have been using chlorine in the Gore and Mataura water supplies for many years.

Why does the water smell different?
The smell is caused by the chlorine reacting with the the natural organics in your tanks and pipelines. The odour should decrease with time as the chlorine removes the organics from the water.

I don’t like the taste of chlorine – what can I do?

You have a couple of options.

  • Fill a jug of water and leave it on the bench or in your fridge overnight. The chlorine will dissipate naturally over a few hours.
  • Install a carbon filter which removes the chlorine.

Should I get a water filter?

We recommend waiting a week or two after chlorination starts before deciding whether you want to install a water filter as any initial smell and taste issues may disappear or at least be less noticeable.

Where should I fit a water filter?

You are best to talk to your plumber about this as it will depend on whether you want to filter the water for your entire home or just at your kitchen sink. Local plumbers are aware of our plans to start chlorinating the scheme.

How much do water filters cost?

Again, it is best to talk to your plumber. Costs for filters can range significantly depending on the type of filter and the installation costs.

How will you know the chlorine is effective throughout the entire scheme?

We will be closely monitoring water quality and initially carry out regular tests at selected sites.

Will my stock drink the water?

Yes it is not uncommon for stock water scheme’s to be chlorinated. Nevertheless, it might pay to keep an eye on stock initially as any taste or odour issues will be more prevalent then.

What about pet fish?

If you have fish in outside ponds you will need to either turn down in-coming water to an absolute trickle (this dilutes the chlorine level to a safe amount for your fish), or fill up drums of water and let them sit for at least 24 hours before using (the UV of the sun evaporates chlorine).
For fish tanks or bowls inside, fill up a container of water and let it sit for at least 24 hours and then only replace 1/3 of this water at a time with what is in the tank already. If you’re still worried, you can buy de-chlorinating kits (sodium thiosulfate) at pet supplies stores.

Will chlorinating the scheme mean it will meet New Zealand Drinking Water Standards?

No. Chlorinating the water on its own is not enough to meet the requirements of the New Zealand Drinking Water Standards (NZDWS). We are currently investigating the level of treatment required for the scheme to meet national standards. However, these are likely to take some time to implement, hence the decision to chlorinate the scheme in the interim.

Our Common Questions sheet can be downloaded here. [PDF, 392 KB] 

Further reading


New connections

If you want to apply for a connection to the scheme you can apply online [PDF, 146 KB] or phone our 3 Waters team on 2090330.


Scheme Management

The Council presently manages the scheme in conjunction with the Otama rural water scheme committee. Users have voted to take over the ownership and management of this scheme. This will require a Local Members' Bill to be passed.

How does the Council know if E-coli is in the water at the Pyramid Pump Station?

  • A weekly water sample is taken from the Pyramid Pump Station.
  • The water sample is analysed for E-coli at the Watercare Laboratory, in Invercargill. This process takes approximately 24 hours.
  • If there is E-coli present in the sample taken, the laboratory is required to notify us immediately. The Council then issues a boil water notice.

Can the Council guarantee the quality of the water at all times?

  • No – even though the water in the scheme is now treated, it is not continuously monitored and the levels of chlorination will vary at different points on the scheme.
  • With water samples collected only weekly it takes 24 hours to get the test results. This means there is a risk E-coli could be in the water supply for a number of days before we are aware of it.

Why is a boil water notice issued and when is it lifted?

  • A boil water notice is issued to the scheme users as a precaution to help prevent any user becoming ill from the E-coli in the water.
  • A boil water notice means all water intended to be used for cooking or drinking should be boiled for at least one minute before use.
  • We take daily water samples at the site until the results show E-coli is absent in the water supply.
  • The boil water notice can be lifted after three consecutive daily tests show an absence of E-coli.

How are scheme users notified about the boil water notice?

  • We notify scheme users when the boil water notice is activated and when it is lifted using the following  channels:
    • We send out an email and text alert to scheme users. This goes to all users who are registered on our scheme alert database.
    • An urgent notification is aired on Hokonui Gold 92.4 and CaveFM 106.4 radio stations.
    • A public notice is placed in the Ensign newspaper.
    • We have an urgent alert on the home page of our website and display information on our water and public notices page of our website
    • We post a notice and updates on our Facebook page.

What can I do to ensure I get a notification?

  • To ensure your email and cellphone details are on our database you can either
    • Phone our 3 Waters team on (03) 209 0330.
    • Email us at info@goredc.govt.nz with the subject line Otama Rural Water Scheme Information Update.
    • Private message our Facebook page.

What can I do to ensure the water is safe following a boil water notice?

  • After a boil water notice is lifted, there is still the potential for E-coli to be present in your water tanks. Below are some safe chemicals that can be added to the water to remove any E-coli and still be safe enough to drink.
    • HTH tablets – These are small tablets that can be added to the tank to add chlorine to the water to help kill E-coli. It is commonly used in swimming pools.
    • Talk to your local hardware stores or stock firms about a product called GeoSil150. This product can be added to the tank water to kill the E-coli.

Gore District Council 29 Bowler Avenue Gore P: 03 209 0330 E: info@goredc.govt.nz