[pct-l] How do water caches work?

[Diane Soini of Santa Barbara Hikes]

I don't think anybody is trying to sound arrogant about hiking the  
first 20 miles without a water cache. The PCT contains many sections  
of 20 miles or more without water sources. It is a reality of the  
PCT. People should be prepared for this reality since water caches  
cannot be considered truly reliable and neither can ever potential  
natural water source. Recently I did a 3-day weekend backpack trip/ 
trail working trip where all the water needed had to be carried in on  
Saturday. I discarded 2.5 liters of excess on the following Monday.  
Having to carry a lot of water is not a huge hardship, just an  
annoyance.