You can boil water to make it softer. Boil for at least 10 minutes, then let it cool. The boiling process causes calcium and magnesium, which cause hardness, to evaporate.
Another option is to buy a filter. Water from the tap is softened through a portable unit. It removes chlorine and other minerals and helps make the water more palatable to drink. Most portable filters can be purchased in grocery stores, supermarkets and specialty bed and bath stores.