Emergency Water Supplies – Rain, Snow, Ice, and Dew
You've undoubtedly heard or read that people can survive for only a few days without water. And so finding a safe source of water becomes a top priority in just about every survival situation where rescue could be days away. Precipitation can often be an excellent source of water requiring little effort on your part to procure.
If you have shelter, rain can be a blessing since it provides safe water for you to consume. Except in places like tropical forests where rain comes down like clockwork, you may not get much warning. As such, it's important to prepare ahead of time to collect rain so that you can go about your other survival tasks.
With rain, the key tactic is to have as many collection points as possible. This means placing as many containers out as possible and ensuring there is nothing between them and the sky. In addition, if you can fashion gutters out of bark, plastic, or other materials you can significantly increase the surface area for catching the rain.
If you don't have any containers, your next best bet is to look for naturally occurring containers where rain may have collected. This includes rock crevasses and fissures.
As a kid, you probably ate snow or bit in to icicles. Not so much because you were thirsty, but because it seemed like a treat. The problem with eating snow when you're doing it to survive is that it lowers your core body temperature. Something you want to avoid if shelter and warmth are not at your fingertips.
The proper technique involves collecting snow, the fresher and cleaner the better, and then finding a way to melt it. If you have a fire or stove, melting it won't be an issue. If these two options are absent, but you do have some additional water of your own, you can blend the two in a bottle and then agitate the blend to melt the snow. To help the melting process, you can also place the container between layers of your clothing, but be sure it isn't directly in contact with your skin.
If the conditions are right, the morning will bring with it dew that you can collect. You'll have to be ready to go as the dew will eventually evaporate as the day progresses. First off, you'll need to gather materials that are absorbent such as t-shirts and socks. Dew collection is as simple as passing the materials over the surface of grass or rocks where the dew has formed. Then wring out the water in to your mouth or a container.
Saltwater is dangerous to drink as it causes your body more harm than good in large quantities. However, old sea ice is usually salt-free and therefore safe to drink. Typically, old sea ice is blue, brittle, and has rounded edges whereas new ice is gray, hard, and salty. As with snow described above, you need to melt the ice before you consume it.
Wilderness Survival by Gregory J. Davenport