|Yes, I see water as major problem under a long term crisis.
It comes at two levels: Drinking water and other uses. If you've got enough storage space, you can keep drining water in sealed bottles, bought at the grocery store - they usually have a shelf life of many months. Of course you can fill up a large canister of tap water, but even though it is usually fine for drinking today, it isn't guaranteed to be bacteria free. Six months later you may want to boil it before drinking it. Bottled water is easily circulated in a FIFO manner, but few of us do that with tap water canisters, so you should have a routine refreshing that water every x months.
There is a second essential use of water: Even if water is closed off for as little as six hours (e.g. when they dig in the streets to do work on the pipes, or a pipe is broken): You can flush your toilet only once! The authorities always provide drinking water from a large movable container, but you can't run out to get a bucket of flushing water.
My (coming) solution to the problem: I will be digging a lot in my garden this summer, remodeling my house, and put a five cubic meter rainwater cistern into the ground. This is for several reasons: During a draught, 5000 liters of water for my vegetable garden will be substantial. During heavy rain showers, it helps prevent flooding. And, for emergency situations, I can pump up a bucket of water for the toilet. The cistern inlet will be equipped with a prefilter to keep most of leaves and particles out. If I pump up water, I can put it through a finer filter and boil it, as emergency drinking water.
I guess that I am lucky, having this option available. If you live in a 7th floor apartment, you probably won't be able to collect much rain water!
For the electricity:
I am switching to 12VDC LED lights. I just bought six large solar panels, 6*320 Wp, and two lead accumulators. The controller is hooked up to the grid, so in winter when the panels cannot keep the accumulators fully charged, they will be kept charged from the grid. I can also run my Internet fiber connection from the accumulators, the battery radio (when it runs out of batteries) and charge my telephone and laptop.
About 5 kWh of electricity (continously refilled by the panels if there is sun or bright daylight) is probably sufficient for lights. You can't run a freezer on it, or high-power equipment like a dishwasher. You can't heat water for the shower. For the fridge/freezer, I have got a small generator (originally bought for camping trips in my box car) to run them for a couple of hours every day.
For hot water, I am installing a propane heater, the kind intended for off-grid cabins, both as an emergency heater and in everyday operation as an after-heater when I need glowing hot water. The heat pump driven hot water tank is kept at about 50°C (except under the regular legionella desinfections) which is fine for showering, but not for everything else.
For cooking, I was laughed at, going for a split propane/induction solution: Around here, gas stoves are virtually unknown. (We know them only as something used in other countries.) But I was about to make a grave mistake: I had decided on one model, and made a final check of the specs before finalizing the order ... to discover that it had security mechanism that turned off the gas immediately at power outages, making it useless. There was no way to override this. So when I found another model, before ordering I got in writing from the manufacturer that the stove will work even during a power outage - the electric igniter will not, but I can ignite it with a match/lighter.
To keep the house warm, I have heat pump driven floor heating, which requires electicity to run. I discovered that high effect (4-5 kW) portable propane heaters are fairly cheap, well below a hundred Euros. So I got myself a couple of those, both for emergency situations, and as boosters to rapidly get the heat up e.g. when you return home after having been gone for a couple of days. Or you can put the heater in your car when you go to the mountain cabin, to rapidly get it warm.
Twenty years ago, the grid was rock steady, no outages at all. Nowadays, they do so much "optimization", tying various supply lines up in a tightly connected network, that everyhing depends on everything else. Problems anywhere in the grid, e.g. a transformer breakdown, ripples through the grid, turning off everything miles away from the source of the problem. The last few years we have had 1-3 outages a year, each lasting only a couple hours where I live (in rural areas, they may last for a day!). I can't recall any case were the real problem was in my neighbourhood; it was all ripple effects. A couple hours without electricity isn't disasterous, but keeping light and communication running certainly is good.
I think I have taken care of most water and electricity issues: Light, hot water, cooking, heating, fridges/freezers, communication. At least I am a lot better prepared than most of my friends!