The Orlando Sentinal has an article that explains why fountains like Epcot's Dancing Waters have closed for extended periods of time this spring/summer. The good news is that Epcot's popular fountain should be back and running by the end of this month. Here's a link to the article:
http://orlandosentinel.com/business/tourism/orl-bizepcot01090101sep01.story
http://orlandosentinel.com/business/tourism/orl-bizepcot01090101sep01.story