Your best bet would be action through local politicians. A big issue for Toronto residents during the recent provincial election was watershed being destroyed by construction. Some (many?) people voted for the current premier because he promised to stop the construction. Unfortunately, it looks like he's gone back on his promise already:

http://www.globeandmail.com/servlet.../TPEnvironment/

You could always get that crazy Florida writer involved (the one who always kills developers in his books? Shit, what's his name!?!)