Foley: Backcountry hydration
November 22, 2016
Maintaining hydration is critical for any physical activity. In the backcountry, where drinking water may not be readily available, it is especially important to have a hydration plan. Dehydration can become a serious problem if fluid intake is not maintained. Initial symptoms of dehydration include dry mouth, weakness and dizziness. In more advanced dehydration a person can become sluggish, confused and even faint. The heart rate becomes elevated with an associated loss of blood pressure. The inability to sweat and dark colored urine usually indicate advanced dehydration. In extreme cases symptoms can progress to seizures and unconsciousness.
Even slight dehydration can be a problem if your activity requires agility and sharpness. Sometimes not being able to travel at planned rates can lead to being caught out in bad weather or darkness.
How much water should you drink
The amount of water you should drink daily depends on many factors including your size, outside temperature, activity level and duration. When I have an all day hike planned I carry two liters of water, plus I will pre-hydrate by drinking at least a half of a liter before starting. Of course if there are no streams or lakes you've got to carry enough to see you through. Water weighs more than 2.2 pounds per liter so if you are trying to pack light, have a plan to replenish at known water sources.
Some people contend that the chance of getting Giardiasis, a sickness caused by Giardia cysts in the water, in the backcountry is minimal. Well, if you've ever had it, you're a believer in not getting it again. Giardia is a single celled parasite that colonizes in the small intestine and the symptoms are quite unpleasant. Since we are not in a Third World country where water is more likely to be contaminated by viruses and bacteria, Giardia is the primary danger in lake or stream water. Another, similar parasite not as common in the backcountry is Cryptosporidium.
Giardia and other parasitic cysts can be eliminated by several methods including boiling the water, filtration, chemical additives and ultraviolet light treatment. Each method has advantages and disadvantages.
Boiling your water is always an option and is 100 percent effective against cysts, bacteria and viruses, but it is time consuming. Of course you have to have a fire or a stove and a suitable pot or container. You end up with hot water, not the most satisfying thirst quencher.
The primary chemical additive is iodine in the form of tablets. They are inexpensive and easy to carry. Down side is it takes at least 30 minutes to work and then there's the residual iodine taste. There is a taste neutralizer available. Iodine will take care of viruses and bacteria as well as Giardia but does not work for Cryptosporidium.
Chlorine dioxide is another chemical option, a little more complicated to use, but has a longer shelf life than iodine. Works for Cryptosporidium.
Ultraviolet radiation devices work quickly and eliminate all microorganisms but have a high initial cost and depend on batteries to work. Reliability has apparently improved with recent product upgrades.
Water filters come in a variety of types and styles. Most will filter out the problem cysts and bacteria, but will not filter viruses without a chemical component. The simplest are the relatively new straw style filters that you can use to drink directly from the water source. Most will also hook up to a standard bottle thread so you can fill a bottle and drink through the straw or squeeze the water into your clean container. You can rig or buy a gravity feed system. Gravity feed takes time. Pump style filters deliver water at rates of a liter a minute or more and work quite well for replenishing group supplies or where water supplies are separated by many hours of traveling.
Sub-freezing temperatures add another level of difficulty as the only way to replenish your water supply is to melt snow or ice. Water stored in a pack or even inside your coat can freeze while traveling. Fresh snowpack is usually clear of microorganisms, but it takes a lot of heat energy and time to make water. Try starting out with hot water or tea in your bottle or bladder.
Search and Rescue personnel always start out with at least a liter of water in their pack, more if there is none available in the work area. Typically, each will have some iodine or a small filter in order to replenish. In the winter each field team will be carrying at least one stove. We are always reminded to watch out for each other, checking for symptoms of dehydration. You should consider a similar plan for your backcountry travels.
Greg Foley is a member of Grand County Search and Rescue and has been a mountain rescue volunteer for 36 years. He can be reached by email at firstname.lastname@example.org. The GCSAR website can be found at grandcountySAR.com or on Facebook/GCSAR.