What Are Recreational Water Quality Standards?

What Are Recreational Water Quality Standards?

Water quality standards indicate the safety of swimming in New Zealand oceans, rivers or lakes. Recreational water standards define the maximum concentrations of contaminants in water before it becomes risky for people and the environment.

What Are Recreational Water Quality Standards?

Recreational Water Quality Standards are limits set by official agencies, like governments, based on scientists’ advice. Such standards define the maximum concentration of a contaminant in water before there is a risk to people or the environment. For example, the maximum concentration of E. coli in the water may be 100 units of E. coli for every 100 millilitres of water.

Recreational standards usually focus on indicator bacteria, which are used to detect the level of fecal contamination in the water. They are considered a better indicator of human sewage than other types of bacteria because they are found in the intestines of warm-blooded animals. E. coli is the type of bacteria that local health authorities look for in freshwater. Enterococci is the indicator bacteria for marine and brackish waters.

The Water Quality Standards for Swimming in New Zealand

LAWA uses swim icons to indicate water quality and the swimmability of lakes, rivers and beaches.

The green swim icon means the water is suitable for swimming, as the waterbody is being routinely monitored. For beaches, it indicates there is equal to or less than 140 Enterococci / 100 mL. For rivers and lakes, it indicates there is equal to or less than 260 E. coli / 100 mL.

The orange swim icon shows that the waterbody is being monitored more, as the source of increased Enterococci and E. coli is being investigated. For swimming, it means caution is advised. For beaches, it indicates there are more than 140 Enterococci / 100 mL, and for rivers and lakes, more than 260 E. coli / 100mL.

The red swim icon acts as a public warning for swimming. The waterbody is unsafe for recreational activity, and monitoring is increased to investigate the source of the increased contamination. For beaches, it indicates more than 280 Enterococci / 100mL, and for rivers and lakes, it indicates more than 550 E. coli / 100 mL.

Other Water Quality Standards

Water quality standards are the rules and guidelines that specifically tell you what you can and can’t put in the water. While some water quality standards refer to the natural environment, like what is in your lake, river, or ocean, other standards refer only to drinking water or farming water usage.

The National Target

The national target aims to increase the number of rivers and lakes suitable for swimming, decrease the number of rivers and lakes unsuitable for swimming, and overall see improvements in the water quality and swimmability of water bodies across New Zealand.

The National Target Water Quality Standards NZ

Source: Ministry for the Environment

What the National Target Means for Swimming

The national swimming water quality targets are based on five categories: the best three (blue, green and yellow) are suitable for swimming, and the worst two (orange and red) aren’t.

The Importance of Water Monitoring

Why Can Poor Water Quality Cause Illness?

While the presence of a small amount of bacteria (often measured by the number of bacteria per 100 mL of water) may pose little to no danger to swimmers, higher concentrations may pose a risk to young children, the elderly and people with compromised immune systems. Concentrations of bacteria can often rise to levels where swimming is not recommended for anybody, despite their age and health.

Water Quality-Related Risks

Recreational standards focus on water quality in places people are most likely to be in or around the water and its associated risks.

Primary contact means putting your whole head under the water, like when you swim, surf or dive, and are more strict due to the higher chance of swallowing some of the water. In poor water quality, primary contact can lead to significant adverse impacts.

Secondary contact means you are near the water, like when you paddle, sail or fish. Secondary contact indicates you’re less likely to swallow the water. However, poor water quality can still put you at risk.

When water bodies are contaminated by human or animal faeces, water can carry disease-causing bacteria, viruses, and other illness-causing particles like salmonella. Such organisms present health risks in water used for recreational activities, like swimming. The most common illness is gastroenteritis, a bacterial or parasitic infection that irritates the digestive tract. However, other respiratory illnesses like ear and skin infections can occur.

Faecal Indicator Bacteria

The water quality for swimming is determined by measuring and monitoring ‘faecal indicator bacteria’, or enterococci in coastal waters and E. coli in rivers and lakes, which indicates the potential levels of disease-causing organisms in the water.


Algae, cyanobacteria, can be potentially toxic and become a problem in lakes and rivers with large amounts of algal blooms present. Specific cyanobacterial species can be known to produce toxins, but they are not necessarily toxic all of the time.

Smart Water Quality Data Interpretation with AI Software

Where to Check for Up-To-Date Swimming Information?

Before going swimming, checking for up-to-date information can be crucial, especially in the warmer months. There can be statistical uncertainty associated with each swimming category at the monitoring site level.

Other factors can affect how suitable a waterway is for swimming, including:

  • Water flow
  • Water access
  • Heavy rain events
  • Weather conditions

Improving Swimmable Waterways

In 2017, the New Zealand government said it was OK to swim in about 70% of the country's rivers and lakes. By 2040, it aims to make 90% of rivers and lakes swimmable using the new Clean Water Package standards.

The government plans to replace the old National Policy Statement (NPS) for Freshwater Management standards based on the E. coli contamination levels in rivers and cyanobacteria levels in lakes, with standards focused on the amount of time a waterway exceeds healthy and nontoxic amounts.

The term 'risk', which is referred to when discussing water quality standards, means that if contamination levels are high, like high concentrations of E. coli, it can result in infection. The new proposed government plan is claimed to lower gradings which allow for more risk while not increasing the chances of contracting an infection if you swim only where you're supposed to.

The Swim Smart Checklist

Following LAWA's advice, use the simple swim smart checklist before swimming, including looking for water quality, clarity and hazards.

Water Quality

Check the water quality information for the swim site. Know how to spot potentially toxic algae so you can avoid it. Also, avoid swimming near potential sources of contamination like flocks of birds or near stormwater or wastewater outlets.

Water Clarity

Avoid swimming for a minimum of two to three days after heavy or prolonged rainfall, even if sites indicate good water quality. You can check if the water is clean and clear if you can see your toes in calf-deep water, but if not, wait until the water is clear before dipping in.

Water Hazards

Look for potential hazards, like strong currents and tidal rips, underwater objects, or even stinging jellyfish near the ocean. Be aware of any warnings and alerts and follow safety advice.

The RiverWatch Solution

The Waka is a real-time water quality solution. From governments to Iwi to farmers, we're working with Kiwi's to help understand their water and observe changes in the moment rather than after it has happened.

The Waka

The RiverWatch mission is to empower New Zealand to achieve clean, swimmable rivers and streams through providing real-time water quality information. We're committed to restoring and enhancing freshwater.

We aim to become zero waste and carbon positive. The goal is to provide sustainable management of New Zealand's rivers and streams with our robust and affordable water quality monitoring product.

Get in touch with us to learn more about RiverWatch and our innovative water quality monitoring solution.

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