There's water everywhere, even in the desert. But, collecting that water for use can be a challenge. Here's some hints on finding or making a water supply for some wilderness settings.
Conserve What You Have
First of all, conserve what water you have by following these tips to survive:
- Perform only necessary activity
- Work and walk during the coolest parts of the day, usually early morning before the sun rises
- Rest in the shade, on grass or by bushes for more cooling from their release of water vapor
- Stay covered with a layer of clothing
- Breath through your nose rather than mouth
- Only eat if you also have water to drink - food takes water to digest
- Smoking consumes water
- Drinking alcohol consumes water
- Eating fatty foods consumes extra water to digest it
- Check the color of your urine. If it is becoming dark, you need more water. Urine should be light colored, not dark
Early in the morning, wipe a cotton t-shirt or other absorbent cloth over long grasses and leafy bushes to collect the dew. Depending on the location, you can collect a pint, quart, or gallon of water this way. Its an easy way to get clean, fresh water. Be careful of what types of vegetation you wipe so that you don't also collect harmful oils.
A solar still can be a useful water supply in an emergency.
Find a low, damp spot in direct sunlight - a dry creek bed or southern base of a hill. Dig a hole about 4 feet across and 3 feet deep. Dig a smaller hole in the center of the bottom and place a cup in the small hole. Pack earth around it to hold it in place and prevent tipping. Cover the hole with a 6 foot by 6 foot piece of clear plastic sheet. Cover the edges of the plastic with sand or dirt to hold it in place and stop moisture from escaping. Place a stone in the center of the plastic sheet. Adjust the edges of the plastic so the rock sinks down directly over the cup and about 2 or 3 inches above it.
Now, wait. And wait. And wait.
The sun will heat the soil in the hole releasing trapped moisture. The moisture will condense on the plastic sheet, dribble to the center, and fall into the cup. Lift an edge and retrieve the cup when it has water. There should be some water after an hour or two and it will be safe to drink.
You can improve this still by placing a 6 foot plastic tube into the cup and have it run up and out of the hole. Then, you can just suck from the straw instead of disassembling the still to get to the water.
Solar stills can extract moisture from even desert soil. If the soil is very dry, you can fill the bottom of the still with grasses so their moisture evaporates and condenses.
The same sort of plastic sheet used for a solar still can be suspended and used to collect rainwater. Rainwater collected directly from the sky could be drunk. After a rainfall, you could lay out your sheet under bushes or trees and shake the water off of them.
When its cold, you don't feel like you need to drink much. But, that is a serious mistake in winter. The air in winter is usually drier than summer and your body continues to expel water vapor with every breath and every exertion. You also need water to generate heat in your body.
Winter has special challenges for collecting safe water. Water filters will most likely break if used in freezing weather. Either the filters will freeze closed and allow no water to pass or the water expanding to ice will break the filter, making it worthless. So, you will need to purify by boiling or chemical treatment. Since I have to heat ice to water anyway, I prefer to just keep going and boil it.
Here's some things to keep in mind for your winter water supply:
- The water will be either snow or ice or very cold water in a running stream. If you consume snow, ice, or cold water, your body uses up energy to warm it and it may lower your core temperature - watch out for hypothermia.
- Either boil or chemically treat raw water - do not directly eat snow or ice because it can be contaminated with bacteria.
- Catch snow while it is falling. Use a tent tarp or plastic sheet. Or, collect fresh snow off the ground if it is a deep snow. This fresh snow can be melted and consumed without boiling.
- Chemical treatments take longer to have effect when the water is cold. Add the chemicals as soon as the snow or ice is melted and warm, before it cools off.
- Boiling snow or ice will take more time and fuel since it must be converted to liquid, then raise to boiling.
- If you have a choice, use ice instead of snow. Ice takes less time to melt and yields more water.
- Pour water retrieved from snow or ice through a coffee filter to remove dirt, bugs, and junk.
- Once your water is boiled or treated, fill your water bottle and keep it inside your jacket or sleeping bag. The extra heat will keep you warm and you will keep the water from refreezing and breaking your bottle.
- Mix lemonade or Gatorade into your water bottle to lower the freezing point a small amount.
- Keep your water bottle upside down so ice forms on the bottom instead of at the opening.
- Don't fill your water bottle completely - leaving room to slosh around helps keep it from freezing.
- Don't drink much water before bedding down for the night. Getting up in the night wastes sleep, energy, and heat.
labeled with ICRA merit badges boy scouts