jen, bees are just as much pollen hoarders as they are nectar hoarders, it is said, if it's available it's collected and also collected according to a hives needs.......pollen is much needed year round, raising babies, complete nutrition for themselves and much needed when the queen starts laying in late winter, early spring. water(not stored to my knowledge and experience) is used for many purposes by bees; the bees utilize water to cool the hive (evaporation like an air conditioner), for larval and egg development, for the nurse bees that feed developing larvae, and during winter months to dilute honey crystals to a liquid form. for those of us in northern winters, water comes from moisture collected in the hive itself.