Swimming & shellfish

Environment  Southland monitors popular sites for swimming or gathering shellfish.


Where to swim and collect shellfish

Download our factsheet Where to swim and collect shellfish here.

We are lucky enough to have some wonderful spots in Southland to swim and gather shellfish but we need to be aware that bacteria levels in the water can make us sick. Harmful bacteria gets into our waterways through human and animal waste. This can be from sewage, septic tank discharge, farming run-off, industrial pollution and boats. The main risk swimming in or swallowing water where there are high bacterial levels is gastroenteritis, but infections of ears, eyes, skin and the respiratory tract may also occur.

Environment Southland carries out regular monitoring for harmful bacteria at popular swimming spots from December through to March (3 beaches, 7 rivers, and 2 lakes). Environment Southland also monitors water the water at 8 shellfish gathering sites for harmful bacteria monthly, throughout the year. To help you work out the best place to swim or gather shellfish, we put our monitoring results on our online map, Beacon, but there are other things you need to think about too that might affect the water quality at the site you are headed to.

Using our SMART tips, you can choose a good place to swim or gather shellfish. Making a decision about where to go is all about combining the information that Environment Southland provides, along with your own observations and checks. It's easy to use our maps and SMART tips, and you can find out more about our recreational water quality monitoring here

SMART tips stand for Site- check our sites online for M- our monitoring results, consider A- additional factors that can affect water quality (like recent rainfall), think about other R- risks- such as submerged objects or strong currents, check for T- toxic algae which can make the water unsafe.  See more information below:

SMART tips

Use these tips to check out water quality when planning activities:


Popular sites for swimming are listed on the LAWA (Land Air Water Aotearoa) website, and Environment Southland's online mapping service Beacon, which also includes popular shellfish gathering spots. Its here that you can see the results of our monitoring.  Remember: It's important to also check for flood warnings at the spot you plan to visit using Environment Southland's water level map, which will tell you if there is a flood warning.


Swimming sites: Over summer (December throught to the end of March) we test these swimming sites weekly for harmful bacteria. We use a traffic light system show if a site is OK for swimming. If the spot on the map is green, the risk of getting sick is very low, so it's OK to swim once you have checked the additional factors and risks. If it's orange or red the risk is higher, and you need to stay out of the water at this site. The Beacon map for swimming displays the last four sample results for each so you can get a good idea of the recent history of water quality there.

Shellfish sites: For shellfish, we test for harmful bacteria in the water every month throughout the year at known collection sites. We use a pass/fail overall grade determine if a site is OK to gather shellfish. If the spot on the map is green, it's OK to gather shellfish once you have checked the additional factors and risks. If it's red, it's not safe to gather shellfish.

Additional factors:

Because our samples are taken weekly and water quality can change, you need to consider these additional factors before heading out to swim of gather shellfish:.

  • Heavy rain can wash contaminants or runoff  containing more bacteria into our waterways. We recommend no swimming or gathering shellfish for at least two days after heavy rainfall. See Environment Southland's rainfall info here.
  • Avoid swimming near stormwater outlets.


When at the site, look around and weigh up any risks you can see before you swim or gather shellfish.

  • Check for submerged objects, swift water or strong currents.
  • If you can't see your toes when standing knee-deep in water, the water may be unsafe to swim in.
  • If you see signs stock have been in the water or there are visible signs of contamination, stay out of the water.

Toxic algae:

Check your swimming spot for any excessive green/brown slime on rocks or in the water, or dark brown/black mats at the waters edge – it could be toxic. Stay out of the water and keep dogs away from the slime, and report the location to Environment Southland. Keep up to date with toxic algae alerts via our system on Beacon.

Swimmable lakes and rivers


The Government has set a national target of making 90% of New Zealand's large rivers and lakes swimmable by 2040, with an interim target of 80% swimmable by 2030.

Regional councils are required to develop regional targets to contribute to the national target. They must make draft regional targets available to the public by March 2018, and make their final regional targets public by the end of 2018.

This means that, over the coming year, each regional council will work with their communities to decide which rivers and lakes will be improved, when, and by how much, in order to contribute to the national target. Each council will be looking at the actions needed to achieve the targets. In Southland, this will take the form of community conversations under the People, Water and Land programme.

To date: Environment Southland has released a draft regional target for swimmable lakes and rivers by 2030.

Under the Ministry for the Environment's National targets for swimming water quality released in 2017, Southland's rivers were deemed 60.2% swimmable and 98% for our lakes.

This assessment used modelling to grade rivers and lakes into different categories according to how often the levels of bacteria are at such levels that the rivers or lakes are suitable for swimming. The purpose of modelling this information was to help regional councils assess how much improvement was needed in order to meet the government's national targets of 80% of lakes and rivers swimmable by 2030 and 90% by 2040.

Using the Ministry for the Environment modelling, Southland's rivers will see a 5.5% improvement by 2030, taking our target to 67.5%. The modelling takes into account the current work being undertaken across Southland to improve E.coli levels, combined with the actions required in the proposed Southland Water and Land Plan. For more information see Targets for swimmable lakes and rivers in Southland

Announcing the target is a significant step in recognising where we are at, and where we need to go in improving water quality across the region. While the target seems low, it is a measure of the work being undertaken by our communities, and the work we have planned to help achieve the government's targets. With our People, Water and Land programme underway, Southlanders will soon have the opportunity to discuss and contribute to more aspirational targets to make Southland's rivers more swimmable.

Frequently asked questions:

What does "swimmable" mean?

Swimmable is a term introduced as part of the National targets for swimming water quality released by the Ministry of the Environment in 2017. See the Water quality for swimming map and corresponding categories at mfe.govt.nz/fresh-water/state-of-our-fresh-water/water-quality-swimming-maps. The new target is 90 per cent of our rivers and lakes are swimmable by 2040.

These maps sit alongside the targets, to help inform community discussions about improving water quality for swimming in their region. The maps are the visual product result of modelling, or a range of tests, which the Ministry has used to grade rivers into different categories, according to how often the levels of bacteria mean that rivers and lakes are suitable for swimming.

This grading was designed to recognise that levels of E. coli in the water are constantly fluctuating due to rainfall and other factors, and therefore the risk to human health varies significantly day to day, or even within a day. By using descriptions about the percentage of time E. coli does not exceed a minimum acceptable state, rather than just saying whether it is safe to swim, the categories aim to demonstrate that risk is constantly changing.

Rather than simply being told that a river is swimmable or not, the categories seek to give people an indication of the likely risk so they can make choices when deciding where to swim. 

What is E.coli and where does it come from? How can it affect me?

Escherichia coli is an indicator of microbial pathogens associated with faecal contamination of water bodies. Microbial pathogens are microbes such as bacteria, viruses and protozoa that can cause illness. Microbial pathogens in the water can enter the body when water is swallowed, or through the ears, nasal passages, mucous membranes or cuts in the skin.

They can cause stomach upsets like gastrointestinal illness, infections, breathing issues, or more harmful diseases like hepatitis A. Microbial pathogens in fresh water primarily come from faecal contamination.

Faecal contamination from animals can occur through runoff from farms during rainfall events, or if animals have direct access to waterways. Human faecal contamination of waterways can occur if poorly treated sewage or septic tank systems are discharged (directly or indirectly) to water, or during heavy rain when sewerage systems overflow into stormwater systems.

Campylobacter (a type of bacteria that can cause gastrointestinal illness) and noroviruses (a group of viruses that can cause gastrointestinal illness) are the pathogens most likely to cause people to become sick from swimming.

How did you get 60.2% swimmable?

All regional councils have worked together to use the best information available to identify:

  • the improvements that will be made to water quality in rivers and lakes in the Southland region under programmes that are planned or underway;

  • when the anticipated water quality improvements will be achieved;

  • the likely costs of all interventions, and where these costs will fall.

A report on these theoretical improvements and costs, presented region by region, is available on the Ministry for the Environment's website mfe.govt.nz. The assumptions and limitations of the modelling approaches taken are described in the report. 

What actions will need to happen to get to 65.7% swimmable?

The first step for Southland will be to implement the proposed Southland Water and Land Plan from 4 April 2018. This will improve land and water management in the region and contribute to 'holding the line' on water quality (preventing further worsening).

The next steps will come through Council's People, Water and Land programme. This programme will take a people-focused approach to integrating action on the ground with regulation (such as setting limits for contaminants in waterways).

Why did the Government release these targets?

The Ministry for the Environment modelled this information for each regional council and released these targets to help regional councils assess how much improvement was needed in order to meet the government's national target of 90% of lakes and rivers swimmable by 2040.

What else do I need to consider before I choose a place to swim?

Using our SMART tips, you can choose a good place to swim or gather shellfish. SMART stands for Site, Monitoring, Additional factors, Risks, and Toxic algae. Making a decision about where to go is all about combining the information that Environment Southland provides, along with your own observations and checks. Find out how to use these SMART tips here.

How does Environment Southland assess suitability of rivers and lakes for swimming and how is this different from "swimmability"?

Environment Southland assesses suitability of rivers and lakes for swimming using both surveillance monitoring and grading. We use 2003 Ministry for the Environment guidelines to monitor water quality (for E.coli) weekly at popular swimming sites during the summer months. This is referred to as surveillance monitoring.

State of the Environment (SOE) monitoring is also carried out monthly to assess E.coli levels. We combine this info together with historical E.coli levels and other risks (sources in the area which might raise bacteria levels) to give an overall Suitability for Recreation Grading (SFRG). The sites where our surveillance and SOE monitoring take place have been identified as popular places for recreational water use.

"Swimmability" is also a form of grading, however it differs from the SFRG grading as it uses the Ministry for the Environment's modelled data. While this includes Environment Southland's surveillance and SOE monitoring data, it incorporates additional data and is a model of swimmability at all of Southland's rivers, regardless of whether these are locations where swimming takes place.

What's the difference between grading and surveillance?

Grading assesses the general suitability of a site for swimming on a long-term basis, while surveillance assesses the suitability of a site for swimming in the short-term (i.e. is it ok to swim today?). A recreational site may receive an 'A' grade (excellent long term quality) but may not be suitable for swimming during specific circumstances, such as unusual contamination.


Page reviewed: 11 Jan 2019 2:14pm