Setting up an enclosed environment using hydroponics techniques for an initial colony wouldn't be too big an ordeal. The limiting factor has always been the prohibitive cost of lifting enough water to sustain human endeavors into space with us. If the water is already there in usable amounts and form, lo and behold, suddenly it isn't nearly so expensive a proposition to set up shop.
For what it is worth, water is abundant in the solar system. That won't be a problem if we ever get started.