You want your main source of food to be accessable. So your pantry should be maintained on a rotation basis.
Your stored food doesn't have to be hidden unless you are not ready or able to protect it from others.
But storage spaces can be found in closets, under beds, in water tight garages/workshops and any outside areas that you have access too. I have a few 50 gallon water containers, that are buried on my property. I use them as a root cellar. Buried ice chests work well also.
Why do you feel you need to hide your food? See if there is a way for you to correct the problem.
Um, how about a storage unit you rent? You could even get a small trailer to hitch to your vehicle and then stock that trailer up with food and water. That way you could just drive in, hook up, and drive away with your supplies. Or, a better solution might be to purchase a used RV pull trailer or motor home and stock that up. You can find places that will store your trailer for you, for a fee, of course. Then you would have food, water, shelter, and a means to prepare your supplies if the worst happens.
If those suggestions don't fit the bill and you still need somewhere to hide food and water, you can bury them. Find a secluded place and use that as your cache spot. Bury your supplies for retrieval at a later point. Be real careful not to let anyone see you bury your supplies as they'll be able to dig them up and steal them.
As for water storage in an apartment, I would suggest a water bed and a good water filter. You can filter the water in your bed for drinking water in an emergency.
If you feel the need to hide food and supplies in your apartment then you're going to have to get creative. Get an old TV and remove the insides, then put your supplies in there. Get old furniture and convert it to hide your supplies in it. If you're really serious and can learn to do drywall, cut a hole in your wall and store your supplies in your walls, then repair the damage you've done to your wall. (Better be real good at fixing the walls or you're not going to get your deposit back.)
Why do you feel the need to hide your supplies? Not criticizing, just asking. Are you concerned that if tshtf your supplies will be confiscated?