This originally came out of California, but I received it from a friend of a friend who works for the Denver Water Company. Find a watershed, fall in love with it, and commit yourself to help protect and restore it for the rest of your life. Help your friends and family fall in love with it to. Make sure one of the places you fall in love with is in your own watershed.
Every year spend some time with it and do a little more to help it.
Over time, your efforts, and those of the friends and family you brought to it can make a significant difference. But keep in mind a prime directive - don't sacrifice other places for yours. Educate yourself and educate others. Learn all you can about the different linkages of issues and science in your watershed. As you learn, share it.