During a hurricane, the public water is likely to become contaminated due to flooding. Since we are on the second floor, we may be protected against our home flooding, but if the power is out there is no guarantee that the pumps will work to push water "uphill" to our home. Thus we need water storage and purification. The minimum needs are two gallons per person, per day, with additional for pets. The two gallons are for sanitation, cooking, and drinking. While they do distribute water & ice in these situations, you have to find out about it and get there before they run out.
For water storage, we currently have empty Gatorade bottles and four trays of 16.9oz water bottles. I know we need to improve this. I'd like to get water purification tablets, as well as a larger water purifier. For purification, the Berkeys are apparently the best on the market. Here are directions on how to make one at home - don't skimp on the filters, either. They'll help keep you healthy, and anything that just promises 'better flavor' won't work for what you need in this situation.