Drinking Water
Keeping Safe Outdoors
Nothing beats a cold, refreshing drink when you’re exploring in the great outdoors. Before rushing in, keep in mind that not all natural waterways – or hut water tanks – are free from bacteria, viruses, parasites or other contaminants. There are a few easy things you can do to ensure you stay healthy when drinking and using the water from natural waterways or hut water tanks.
What Are the Risks of Drinking Unsafe Water?
You may have done plenty of tramping or hunting around Aotearoa and never had an issue with the water– and you’re not alone. According to an Adventure Voice survey on drinking treatment, most people have never become sick from drinking water in the outdoors. Of the 1,544 respondents to the survey, only 8% (127) said they had.
The only way to guarantee the water you drink in the outdoors won’t make you sick, is to treat it. It’s also important to follow good hygiene practices, in particular washing your hands, when preparing food and after going to the toilet.
Water can contain a range of germs that cause serious illnesses. These include:
- Bacteria, such as Campylobacter, Salmonella, Shigella and E. coli
- Viruses, such as norovirus, hepatitis A, enterovirus androtovirus
- Parasites, such as Giardia and Cryptosporidium.
If you become ill, you may experience some nasty symptoms, such as diarrhoea, stomach cramps, and vomiting and nausea. These are never fun, but especially unpleasant when you’re outdoors and away from the comforts of home. On a multi-day trip, sickness from poor hygiene practises or contaminated water can become a real safety concern.
Ways to Reduce Your Risk of Getting Sick From Water
While water in NZ’s outdoors is often safe to drink, there’s no simple on-the-spot test to find out. Even if the water looks clear, it could still be contaminated. There are some common-sense ways to reduce your risk, but treating water is the only way you can be absolutely certain it is safe.
You can’t tell what’s in the water that comes from a tank. Even if it looks clean, it may not be safe to drink. The only way to be certain, is to treat it. Remember, best practice is to follow directions on signs that recommend treating the water.
Check Land Air Water Aotearoa (LAWA) for general information about water quality for the rivers and lakes it monitors.
Methods for Treating Water When in the Outdoors
There are a number of different ways to treat water when you’re in the outdoors to ensure it's safe to drink .
By far the easiest and most effective way to kill all types of germs in water is to boil it for at least 1 minute. At elevations above 2,000 metres, you’ll need to boil the water for 3 minutes. If you want cold water for the next day, you’ll need to boil it the night before so that it has time to cool down. If you are using a bladder or plastic bottle, this is essential. While boiling water is the most reliable way to ensure it is safe to drink, there are a range of quick and easy-to-use commercial options. There are four general techniques – filtration, purification, disinfection and UV light. These vary in their effectiveness, so do your research before you decide the best option for your needs. See the table from the US Centres for Disease Control and Prevention below for more information.
Tips for Collecting Water From Natural Sources
You can minimise the risk of getting sick from a natural water source by where and how you collect the water, but there is no guarantee it will be safe unless you treat it with an appropriate method.
Choose wisely: Free-flowing water is usually safer than stagnant or still water.
Take water from the top: For all natural water sources, collect water from the surface, as it’s less likely to be contaminated. For a stream or river, choose a place where the water isn't churned up and it looks clear.
Take water from the uphill side of a track: If a stream runs across the track, collect it from the uphill side. Not only is it easier to reach, but this also reduces the risk of contamination from people walking through the water.
Make a natural filtration system: For a natural filtration system to be effective, the gravel must be fairly fine. Like other forms of commercial filtration, this method won’t get rid of viruses but may be effective at treating water for bacteria and parasites like Giardia and Cryptosporidium. If there’s a gravelly area beside the water source:
- Dig a small hole until water starts seeping in
- Wait until the water runs clear
- Collect the surface water.
Simple Ways for Preventing Water-Borne Illnesses
Wash your hands: A common source of stomach upsets is poor hygiene. Make sure you wash your hands (either with soap and water or use a hand sanitizer) after going to the toilet and before cooking, eating or handling food, water or beverages.
Be self-sufficient: On day walks, take enough drinking water with you to last your trip. Most trampers need 2 litres a day to stay rehydrated. If it’s really hot, or a challenging trip, you will need more.
Respect signage: Follow directions on signs that recommend treating the water.
Bottom line: To be 100% safe, treat all water from natural sources and hut water tanks, before drinking it.
Guidelines for Keeping Waterways Clean
We are all responsible for protecting the environment and keeping waterways clean. To play your part, follow these universal guidelines when out in the bush.
Make use of the facilities: Giardia and cryptosporidium are spread through faeces (poos) entering waterways. If there is a toilet, use it.
Poop responsibly: If there’s no toilet, go at least 50 metres from any natural water source, dig a hole with a stick or the heel of your boot, do your business and then cover it thoroughly.
Wee with consideration: Urinate on bare ground rather than on top of plants that may be sensitive to the compounds in urine. Put used toilet paper in a zip-lock bag and dispose of it when you get home.
Wash well away from water sources: Do not wash hands, dishes, clothing or yourself directly in streams, rivers, lakes or tarns. Collect water in a container, and move at least 10 metres away from its source before you use it. Once you’ve finished, tip the water into soft soil as this will act as a natural filter.
Questions People Ask About Drinking Water in the Outdoors
It's not always safe to drink water from streams and rivers in NZ. While some alpine and subalpine streams may look clean, NZ waterways can carry bacteria, viruses and parasites, such as Giardia. Even if the water looks clear, it could still make you sick. The only way to be certain water is safe to drink is to treat it first. Boiling is the most reliable method to treat drinking water in the outdoors. Bring water to a rolling boil for at least 1 minute (or 3 minutes if above 2,000 metres). Other water treatment options include filtration, chemical disinfection and UV light treatment, but their effectiveness can vary. To reduce the risk of getting sick from natural water sources, collect clear, free-flowing water and avoid sources near farms, huts and livestock. Alpine streams are generally lower risk, but the only way to be certain water is safe, is to treat it first. To avoid getting sick from water when hiking, tramping or hunting, wash your hands after going to the toilet and before cooking or eating, carry enough safe drinking water on short trips, and always treat water from natural sources and water tanks.
Last edited: August 2026