Why rayhnwater?  Because I really like water.  It's my favorite fluid, and I like working with water and water related systems (thanks to junior year clinic).  I've decided that I am going to go into environmental and water resource engineering.  I think it would be exciting to go abroad and help design and build water treatment and water distribution systems to bring clean water to poor communities in developing countries....a dream now, but someday reality (?).  As for the rayhn part, creative way to spell rain, I guess.  Rainwater was already taken.