Water has been mentioned, and of course is one of the most important of subjects.
At home, I have a little solar powered well pump run by a single solar panel. When the sun shines it pushes water up a hill to my cistern, which gravity feeds my homestead.
The well pump is adjustable and pumps water at the same rate it flows into the well, so the well is never drawn down. This saved allot of coin because my well need not be drilled real far down to hold a reserve of water, and unlike the typical power hog well pump which takes a tremendous amount of energy to power, mine runs on one 120 watt solar panel.
You should have seen the look on the well drillers face when I told him to shut everything down when the hole was "just" 100 feet deep! They charge by the foot, ya know.
Heh, I have a spigot in the yard and one by the barn, no running water in our cottage!
But, as my Doc says "Running water is over rated anyway"
He'd rather I get the exercise hauling it in by the bucketful!
As backpackers we already are familiar with finding and if necessary treating, water.
It's something we do every trip! So again, we have another pretty good advantage over armchair preppers.
Iodine water treatment pills is what I'd pack in an emergency kit. I know this method has lost ground to filters and chlorine base chemical treatments, but consider this angle -
Wikipedia says this about it -
"Iodine treated drinking water, treated with tablets containing tetraglycine hydroperiodide, also reduces the uptake of radioactive iodine in human subjects to only 2% of the value it would otherwise be. This could be an important factor worthy of consideration for treating water in a recent post nuclear event survival situation, where radioactive iodine ingestion is a concern for internal radiotoxicity. If the iodine has precipitated out of the solution, then the drinking water has less available iodine in solution. Also the amount of iodine in one tablet is not sufficient to block uptake. Tetraglycine hydroperiodide maintains its effectiveness indefinitely before the container is opened; although some manufacturers suggest not using the tablets more than three months after the container has initially been opened, the shelf life is in fact very long provided that the container is resealed immediately after each time it is opened"
Also note -
"Department of Medicine, Madigan Army Medical Center, Tacoma, Washington 98431.
Tetraglycine hydroperiodide tablets purify water by liberating 8 mg free iodine/tablet. The effects of ingesting four tablets daily for 3 months on thyroid size, function, and radioactive iodine uptake were studied prospectively in eight healthy volunteers. Serum inorganic iodide increased from 2.7 to approximately 100 micrograms/dL. Urinary iodide excretion rose 150-fold from a pretreatment mean of 0.276 to 40 mg/day. Radioactive iodine uptake was less than 2% after 7 days and remained below 2% in all subjects at 90 days. Mean serum T4 and T3 declined after 7 days. T4 remained below baseline, whereas T3 had recovered by the end of the treatment period. Serum TSH and the TSH response to TRH rose significantly after 7 days and remained elevated at 3 months. The average thyroid volume, determined by ultrasound, increased by 37%. Neither hyperthyroidism nor hypothyroidism was observed. The mean thyroid volume in seven subjects available for repeat determinations an average of 7.1 months after the study was not different from the baseline value. In normal subjects, a reversible TSH-dependent thyroid enlargement occurs in response to the iodine load from daily use of tetraglycine hydroperiodide water purification tablets."