Assuming that this is water ice, it means that long time exploration and even some settlement on Mars is practical. With oxygen drived from the water and water to drink food can be grown (in greenhouses), so air, food, and water would be available and obviously shelter can be provided.
I doubt that life on Mars will ever be practical or self-sustaining. A human presence on Mars will cost a lot of money to maintain, regardless of is found there. And that’s not even taking into account what will happen to resource “exploitation” when the Luddites get hold of NASA budget.