I believe that Trudeau's money would be better spent on road infrastructures instead of water. If they can find money for water then why not for the Ring's road?

You would be right if economics were at play here but it is not. This is strictly a political decision as will be most of his decisions in his first term in office. However what Trudeau does not realize is that in the long run this will not solve any of the aboriginal problems and in fact will likely make things worse by giving in to their unrealistic expectations. It is like a parent buying the screaming kid something they want ( but you can't really afford) to keep them quiet. Just wait till the next time they are in the store.