I have reused 2 liter bottles of water, which I flush and refill every 6 months for 2 years, then I recycle the bottles. This keeps the leaching of chemicals into my water at an acceptable low. Since we live by a river, I also bought a Sawyer Bucket Filter from Thrive Life.com, which can clean up to 170 gallons of water a day (or about 7 gallons an hour) for 16 years. The .02 filter will even filter out viruses,Carefull with your words unless you mean to missinform readers! Only a small race of virons can be removed via a filter, these are the ones that like to clump together like a 'mother' does in vinegar and if you have ever tried to remove mother by filtration, little bits can pass through the filter amd establish itself on the other side.These are the larger sized virons. Average size will zip through like birds flying through a open 2 car garage door~
Remember if someone makes claims that are too good to believe, Don't believe, CHECK THE CLAIMS! ~gd and you can backflush it to clean it. Hauling the water from the river will be a chore, but doable; especially if I can find or fashion an old-fashioned yoke (Lehman's has one, but it's outrageously expensive). The next thing on my list is to get a manual pump for our well, and maybe at least one 55 gallon drum specifically rated for water storage.
I store sugar and molasses which can be used separately, or you can make your own brown sugar from them. Honey is wonderful because it will stay good forever; even if it crystallizes, you can just reheat to liquify again. Oil and lard and butter, whole grains and a good quality manual mill, beans (which can also be sprouted for winter greens), salt, vinegars (wine, ACV, and distilled). Powdered milk, especially if you have children; even if you have dairy animals it's still good insurance. Canned meats (either home canned or commercial) in case the power goes off long enough to lose the stuff in the freezer.
I've been cooking and dehydrating grains (rice, wheat berries) and beans in order to have foods on hand that would take a minimum of cooking time to prepare in case we are somehow reduced to cooking on the charcoal bbq or the campstove.
I can grow most of the herbs I use, and dry them for winter use; but spices are something else entirely. I store spices like pepper, cinnamon, cloves and nutmeg as whole spice so they don't lose their punch as quickly. I have a large heavy mortar and pestle and a nutmeg grater that make short work of any grinding that needs to be done. You can find recipes for making your own condiments and spice mixtures online- I've printed some of them out and have them in sheet protectors in a notebook. My dijon-style mustard tastes better than Grey Poupon.
Although we don't use them regularly, I have disposable plates cups bowls and utensils so that in the event we end up with less water than I'd like, we don't have to use it all to wash dishes. The paper will make good fire starters as well. The alcohol based sanitizers are nice for saving water, as are the waterless cleaners like Cepacol for cleaning the whole body in a pinch.
We bought a Kerosene heater for emergency supplemental heat. Kerosene is more stable in storage than a lot of other fuels. Of course, a wood stove or fireplace would have been great, but we don't have the space or the money... the kerosene heater cost about $150 as opposed to $600 for the cheapest wood stove I've found so far. It will only heat about 450 sq feet, but that's enough to keep at least one or 2 rooms warm-- I'm willing to bunk in the living room if I have to.
I spent time going through and updating our medical supplies as well. Besides the usual stuff, I bought some one-use vials of crazy glue-- good for holding larger wounds together. Another use for "ladies hygene supplies" are as first aid bandages; tampons got their start as bandages for bullet holes in one of the world wars I understand. A couple of 1/2" dowels make handy splints for broken bones. There are antibiotics you can buy for fish and other animals that are identical to the stuff you get from the doctor; do an online search to find more info on that.