All the guide books tell you to boil, filter and chemically treat all water and I will too just to cover my butt in the event of liability issues. I always disregard this good advice, drinking directly from the stream, and thus far have never been sick. If you choose to enjoy the taste of unadulterated stream water too then you did so of your own volition. If the water made you sick then it’s your fault and not the fault of this book or the bear which crapped upstream.

Whatever your choice is get your water from clear running brooks not from lakes or ponds. Water from snow pack is better than water from glaciers. The latter contains too much clay. Carry lots of water, at least 40 litres, whenever kayaking as good water can be surprisingly hard to find on the wet coast of Canada. A green algae bloom in tide pools or wet patches trickling across a beach does not mean something horrible died in the water. It just means the water is brackish. Freshwater will be found up the slope.


Giardia cysts can exist under the most pristine, wilderness conditions. Clear running water is not a sure sign that it is drinkable.

Illustration by Manami Kimura

If your source of water is at a popular camping spot then go upstream away from the camp to get your drinking water. Take great pains to clean yourself and your dishes or clothing well away from the bank of any water body or the water will become polluted. Leftover food does not belong in the water. If fires are allowed and it is safe to do so, burn it. Try to avoid using soaps or detergents but when you must only use the biodegradable kind available from outdoor stores.

Fevered Beavers

Beavers have gotten a bad rap, taking most of the blame for spreading a disease that can just as easily be passed into the water system by deer, muskrats, raccoons, coyotes and squirrels. Indeed any mammal including domestic pets, livestock and humans are guilty of carrying the protozoan parasite into the backcountry.

Giardia lambia, as the microbe is called, enters the environment in hardy cyst form where it can survive for weeks at a time. Giardia cysts can exist under the most pristine, wilderness conditions. Clear running water is not a sure sign that it is drinkable. Ingestation of a single cyst is enough to cause infection in humans. The hard, capsule-like shell dissolves, releasing the infectious form of the parasite which multiplies exponentially.

Full-blown giardiasis may take from 5 to 25 days to manifest itself though symptoms typically appear within 10 days. The giardia protozoa latch themselves on to the intestinal tract, severely impairing the body's ability to absorb nutrients and water. Food and water pass straight through the digestive system instead, appearing as the principal symptom of giardiasis, diarrhea. Infection usually lasts for around two weeks and is usually treated with antibiotics though some individuals may never show symptoms at all and others recover without treatment. Giardiasis has been known to persist for months on end in those with weakened immune systems.

The best treatment of course is prevention and prevention typically means water purification. The surest method of water treatment is boiling. Five minutes at a steady boil will destroy every living organism in the water. Additional time is needed at higher elevations. Boiled water can be bland and dull tasting. Shaking oxygen back into it will help improve the taste.

Expensive, heavy filters are available which claim to strain out giardia lambia. Studies have shown however that not all filters are effective. In order to effectively purify water the filter porousness must be no bigger than 0.2 microns. Such fine filters are hard to pump but produce great tasting water. Chlorine-based water treatments are not effective against giardia cysts. Iodine treatments fare better but studies have shown that a typical 20 minute treatment is not enough to eliminate all cysts. Eight hours is the minimum required for effective iodine treatment. Iodized water tastes horrible however and in rare cases may cause thyroid problems.

The End

Canada's topographic maps are now available for download, free of charge, from Natural Resources Canada (NRCan). Since April 1, 2007 high resolution scans of many different cartographical datasets can be found at  Geogratis, the distribution portal operated by NRCan. Of particular interest to outdoor recreation enthusiasts will be the 1:50,000 and 1:250,000 topographic series.

Unfortunately, the Canadian Hydrographic Service's (CHS) nautical charts are not yet available. Though not as detailed as the CHS charts from a maritime perspective, the Geogratis topo maps should still be quite adequate for most of the kayaking routes described in BC Car-Free. Use charts from the main branch of the Vancouver public library to add in critical details like tidal rapids, campable beaches and so on.

Since the Geogratis portal is not particularly easy to navigate follow a direct link here. Maps are organized according to NRCan map codes. So for example to find the trailhead for the Mid-Coast Trail you will need map 92 E/10. Choose a format then navigate to folder "92". From there choose folder "E" and then move on to the appropriate downloadable zip file.

Detail showing the trailhead of the Mid-Coast Trail.

Personally I prefer the raw scans in TIF format as these retain the highest quality for further editing in a program like GIMP, Inkscape, Photoshop or Illustrator. These can be rather large, often on the order of 30 MB or more.

Frequently a route will skirt the edges of several such maps. The Mid-Coast Trail is a case in point, requiring both 1:50,000 sheets 92 E/8 and 92 E/10. Using editing software these can be ganged up with extraneous details cropped out. Annotations like planned route, known hazards, water sources, safety information and so on can be added, then the whole thing can be printed tabloid-sized [11x17] for ease of use in the field. Of course, always carry paper maps in a waterproof mapcase. Finished maps can be carried in digital format as well, of course, but unless you are packing a solar charger for your device, you may find yourself mapless in the middle of a trip.

Another option is to print a wider view in the 1:250,000 topographic series on the reverse to give a greater sense of the lay of the land.

Whenever resizing any of these maps be sure to copy and paste in an image of the scale at the same resolution so that this can be accurately resized along with the rest of the map. Also include the magnetic declination if available.

The End