Water Filters for River Trips (and Other Clean Water Supply Tips)

Water filters and treatments that purify river water are essential for rafters and kayakers planning multi-day river trips. Here’s a guide to water filters, water purification chemicals, and water containers for carrying clean water with you.

Water containers for river trips

Bringing fresh water with you is the easiest way to ensure clean water. That’s easy enough if you have plenty of raft support. On most multi-day river trips, you should plan to bring enough water for the entire trip. (Check out our guide to multi-day river trip planning for more tips on organizing a private river trip.) You can use filters as a backup by planning stops at clear-flowing tributaries.

Here are a few guidelines for bringing water on river trips:

• Consider the water quantity you’ll need: We plan on bringing at least a gallon per person per day for a hot summer trip. This will cover cooking needs, too. 
• Know that water from any plastic jug tastes bad. Plus, the water from the jug is warm on a typical river trip. To make water more palatable, especially for kids, consider adding a pinch of Gatorade or Nuun, which can also help prevent dehydration.
• Make sure you have enough rafts to haul the water. For a party of 16 people for a 5-day trip, that’s 80 gallons of water, which will fill 16 five-gallon jugs. Where will you put those 16 jugs? Water is one of the biggest factors when we consider how much raft support we need. The good news is you can typically line up those water jugs under the front thwart of the raft: We typically assign 4 jugs to each raft. 
• Keep one jug accessible during the day. One of the last bits of business before you leave camp each morning is to refill water (and coffee!). Once all those personal water bottles are filled, make sure that one water jug remains relatively accessible during the day (not buried in the back of a raft under dry bags) for intermittent fill-ups. If you have a designated lunch stop, get the water jug off the raft and make it easy for people to fill up.

Choose the right water container

• Ensure that it can travel with the spout end on top. If the spout starts to leak at any point, at least gravity will help keep the water in until you get to camp.
• Look for water jugs with integrated lids. If any part of the lid is a piece that you screw off and set aside, that piece will certainly get lost at some point, rendering the jug unusable.
• Look for sturdy containers. Water jugs get bounced around in vehicles, dropped on rocks, knocked off tables, and otherwise abused on river trips. Here are a couple of types to consider:
  • Scepter Water Container: If you’re going for longevity, consider Scepter water jugs, which are BPA-free and made of food-grade polyethylene. They feel sturdy in your hand. However, without modification the spout is hard to pour from. You can add the Scepter Water Container Spout for easier dispensing. 
  • Reliance Eco-Core Aqua-Tainer: We have a few of these, and their main upside, besides the price, is the handy spigot, which tucks into the container for transport. 

Water filters for river trips

Even if you’re bringing water with you, you need a water filter or two as backup. You also might need to supplement your water supply if you’re limited on raft space.

Before your trip, identify the best sources of water for filtering, and plan to stop at those spots. Aim for clear tributaries so you don’t exhaust the filter with heavy-sediment water.

All the filters discussed here are commonly used for backpacking and camping situations. They remove bacteria and protozoa, which are the common concerns if you’re boating in the US or Canada.

Most water filters will not work on viruses such as norovirus, hepatitis A, or rotovirus, although that situation is rapidly changing. Manufacturers such as Grayl have introduced products that filter those viruses.

You can combine filtering with a purifying chemical to address viruses. The Centers for Disease Control (CDC) has a handy chart for determining which water treatment methods work for which contaminants.

You can also remove all contaminants, including viruses, by boiling water for 1 minute, or 3 minutes if you’re above 6,500 elevation. This approach is not typically practical for river trips. But it can work if you find yourself in camp with no clean water, no water filter, and plenty of campstove fuel.

The most practical types of water filters for river trips are gravity filters, bottle filters, and straw filters.

Gravity water filters

Gravity water filters are easy to use and filter the largest amount of water in the shortest amount of time. They’re a great choice for large, multi-day river trips. You simply fill the reservoir with river water, then hang it from a tree branch and let the water filter into a water jug or bottle. This beats pumping water hands down.

Tips for choosing a gravity water filter

• Go for the biggest filter you can find so you can fill those five-gallon water jugs as quickly as possible. Both the MSR AutoFlow XL Gravity Filter and the Katadyn BeFree Gravity Water Filter have 10-liter versions, the biggest we’ve found. Although we haven’t used the Platypus GravityWorks, it has great reviews and includes a secondary clean-water reservoir. (Although we find it easier to just filter into a 5-gallon container, as less water transfer means less spillage.) The Platypus has a 6-liter reservoir but filters at 2.75 liters per minute.
• Check the typical water flow and study the filter system so you know how it works. The MSR AutoFlow filters about 1.75 liters per minute, and the Katadyn BeFree filters about 2 liters per minute. If you’re not getting that flow, make sure that your filters aren’t spent and you don’t have big chunks of sediment blocking the filter. The MSR AutoFlow has a sediment trap at the bottom of the bag, so make sure that is clear. 
• Look for a filter that easily connects to your water container. The MSR has a connector that fits onto a wide-mouth water bottle or jug. The Katadyn has a small plug that can slide into any sort of container. 

Water bottles with filters

In addition to a hanging filter, it’s wise to have several water bottles with integrated filters on hand for various uses:

• For quickly filtering water if the big jugs are buried in the raft load during the day
• For kayakers and stand-up paddlers to carry with them, especially on self-supported trips (no rafts)
• For general back-up purposes

The beauty of water bottles with filters is you can replenish your water supply throughout the day. But the same downsides of filtering water with heavy sediment still apply. Paddlers using water bottles with filters as their only water source will want to double-check the capacity of their bottle filters and make sure they have enough to last the trip. 

Tips for choosing water bottles with filters

• Look for a bottle that filters for viruses as well as bacteria and protozoa. The Grayl Ultra Press uses a press filter that filters norovirus, rotovirus, and hepatitis A, making it suitable for use around the world. Other manufacturers make water filters that work on viruses, but not in a bottle format. Epic Water Filters’ Epic Nano pitcher filters viruses, so it could be a good choice for serving drinking water in camp but otherwise not a great format for river trips. Epic also makes a filter apparatus that fits into a regular Nalgene bottle: Check out the Epic Water Filters The Answer system.
• Find one with a loop for attaching the bottle to your boat. Most water bottles for camping have loops, but it’s a pain if they don’t. 
• Consider a bottle with a straw. Straws make it easier to drink faster (great for kids). The LifeStraw Go Filter is one of the few water bottles with filters that includes a straw. Bonus points: It comes with a carabiner so you can easily affix it to your boat.
• Look at collapsible bottles if you’re low on space. This Katadyn BeFree is a good option. Although it doesn’t have a loop, it would be good to stash in an IK or hard kayak or to have on hand in a dry box. 

Again, if you’re headed to a river where you know norovirus or other viruses are a problem, stick with the Grayl system. But if that’s not a concern, the other choices will work for screening out common bacteria and protozoa. 

Compact straw filters

As a backup or emergency option, consider throwing a couple of compact filters into the load. Useful on side hikes or for carrying in small boats, these micro filters are meant for drinking straight from the water source or decanting into a small vessel.

Two to consider:

• LifeStraw Peak Water Filter Straw is light and inexpensive, screens out bacteria and protozoa, and can be attached to water bottles and gravity filter hoses.
• MSR Trailshot Pocket-Sized Water Filter weighs about 5 ounces, fills a 1-liter bottle in 60 seconds, and you can filter water to a bottle or straight to your mouth. 

Water purification chemicals

If you know you’re headed to a river where viruses are present, bring along some water purification chemicals, which typically come in tablet form. Most tablets need to be added to water a few hours before drinking. So, you’ll need a system for figuring out which water containers have been treated and ready to drink. We use short cam straps of different colors on the water jug handles to indicate whether the water is safe or unsafe.

Here are a few water purifiers that remove viruses (this list doesn’t include purifiers, including iodine, that don’t eliminate cryptosporidia):

• Katadyn Micropur Purification Tablets: Use 1 tablet per liter of water; one package has 30 tablets
• Aquamira Water Treatment: This treatment comes in two different bottles, and you need to mix the contents before adding to the water, so it’s not as easy to use.
• Katadyn Steripen Ultra UV Water Purifier: This gadget is worth a look but has some downsides for a river trip as it is battery-powered and is meant for use with clear water.

Keep your drinking water safe on your river trip

Of all the safety concerns of a river trip, providing clean drinking water should be tops on the list. But with the high-tech filtering options available now, in addition to a good old jug for bringing good water from home, a little precaution will keep stomach bugs at bay for your river party. 

Looking for more river trip planning resources? Check out our essential rafting gear checklist, guidelines for raft trip meal planning, and guide to rafting and paddling clothes.