I have been reading up on. some books "survival theory" for one, and it focuses on EMP and how if you are prepared and people know it they are coming to your place.

It got me thinking and playing with google maps today at work with "walking rates"

our driveway is 1/4 mile and the wife and I walk it everyday to check the mail/ walk the dog. Round trip about 10 minutes so a 20 minute mile waking.
Add stress, hunger, and lack of being in good physical shape. During the Kenosha riots my parents were 25 miles as the crow flies from it.

If for some reason cars were not working would that mob make it 25 miles after days of fighting / starving?

google maps says 9hrs to walk to the center of the riots

I'm further west but still think I'm too close

Not trying to bash my state but I'd say the majority are really out of shape in all age ranges.

just curious if anyone has thought about this or what history shows.
I don't think people are as hard as we used to be.

There are numerous people walking from various countries in South America to the USA, and looking at the photos, I would not consider all of them fit.  What they are is motivated, as would be the people in your situation.  Those folks are provided with supplies, food, water, and such, in your example the people would not get that assistance, so they would have to bring it with them.

You are correct in thinking the average American is not in good physical shape.  Perhaps we could guess 25% would attempt the journey.  Keeping in mind, that as necessity increases, so will their motivation.  If you are near a high population area, that is still a lot of people.  25 miles on paved roads is not that far for a walk, a bike, or to even to push a stroller or pull a wagon (to transport those basic needs (food, water, shelter, etc...).  25 miles over rough ground with elevation changes would be a lot larger of a deterrent - but the ones capable of that wouldn't be bringing wheeled transport for their needs.  They would need to acquire their needs (other than what they could carry) in other ways.

If there is an EMP event that takes out most of the working vehicles along with most electronic devices like many theorize then the one thing we will have going for us is the confusion factor.  I think lots of people will hold onto hope that things will just start working again.  It will take some time for everyone to realize that everything is going to stay broken.  Lack of communication will keep people stationary or at home especially if they are waiting for loved ones to come home as they won't want to leave without them.  AO dependent but I would think it would be a week or two before people start wondering away from their home because they finally came to the conclusion that things aren't going back to normal and/ or .gov is not coming to save them.

With all that said I personally don't buy into the EMP will kill all modern vehicles theory.  I look at history and think we are more likely to experience another Carrington event that fry's everything attached to the grid due to the long transmission lines.  That would put the power out indefinitely and everyone still has the gas left in their tanks or what they can source.

people are resilient and roads are roads even if they don't have cars

even a fat out of shape person will be able to make considerable distance a day on good old-fashioned pedal bicycles.

yes most people are week whiny grasshoppers that will sit and die wherever they are at but a percentage will hit the roads

Wisconsin population is around 6 million toss in another 4 million for Chicago and surrounding area and if only 1% of the population in your AO heads your way and if only 1% of those 1% make it to your area with bad intentions you would be looking at a thousand or so people being in your area and hardened by all the shit they went through getting to your AO.  these are the ones that won't give a second thought to killing you and taking your stuff.

Honestly if you don't have a large, trained group that you can rely on to come together in defense, the best strategy would be to go dark, don't attract attention and ride out the choas for at least the first few months and ideally through the first winter die off.  

You don't think that modern CPUs with tiny gaps that can be knocked out by and ungrounded spark from shuffling on your carpet too hard, can survive an EMP?

Anything fuel-injected would be toast. Then again, I'm not an expert, and nobody on earth truly knows, because it hasn't happened yet.

Back to the question though...

Many americans may try to walk out to the country, and they'll be rich and easy targets for the first wave of bandits. The smartest thing people can do would be to bug in, where they at least have shelter, know their surrounding area, and have much more food than they'll be able to carry anyway.

I would hazard that 99% of those flooding the border didn't get free transportation, shelter, free bottles of water, and meals on wheels. Too many would simply succumb to the elements, word would get out and the migration north would drop to a trickle.  

Not the best example.

I’ve done my own assessment on this. If we’re talking “lights out” with few if any vehicles operational, that also means the vast majority of people have zero information: they’re both figuratively and literally in the dark.

My assessment is that given necessity, limited supply, bulk and weight of water, most people are going to stay in place for the first few days, “waiting for the power to come on or get government assistance”. That waiting will be the death knell for many. Many would have no idea where to even go, not sense of direction on foot beyond their concrete jungle and that doesn’t even take into consideration health issues, drug/alcohol dependencies, or threat of rape, assault, and murder.

We’ve done a bunch of distance backpacking, max distances about 75-100 miles. Pack weight is 30 lbs or less (total weight of food, water, and fuel). We usually don’t push beyond 10 miles for the first couple days, by day’s 3-4 we are start getting to our max of 12-15 miles a day; it took me about six days to hit my first 22-mile day. We are your average section hikers and for our age, probably pretty close to the average, healthy under 30-year-old. Sustaining longer distances is a balance of pace, rest, calories, sleep, and preventative measures to mitigate blisters, sunburn or other aches and pains.

Given that we typically hike during the heat and humidity of the summer months, we also get an early, early start (like before sunup). Our pace is pretty leisurely, so we average 20-30 minute miles (terrain dependent). Even hiking in the cooler mornings, a 12-15 mile daily trek will have us consume about a liter every 2-3 hours, or every 4-5 miles, terrain dependent.

Water. It’s necessary, it’s heavy, and it needs to be potable.

Most people on foot won’t be able to haul enough water for more than a day or two of trekking. Unless they have the containers and means to boil water, access to only moderately contaminated water, or a water filter, their distance will be measure in just a few days let alone miles.

I know we always mention “motivation” and “mental toughness”, how many modern Americans even possess those qualities? Once you cut calories, water, add in environmental stressors (like exposure to the elements) along with physical exertion, the first thing that usually gives out is one’s mental fortitude and cognitive abilities (i.e. you start making stupid decisions).

My assessment for any major metropolitan area/city?

87% remain and die in place or simply scavenge of the other dead but won’t leave.

About 13% will attempt to flee, the majority of those wouldn’t last a day, less than 30 miles giving up due to injuries, lack of water, exposure, simply mentally weak. Less than 3% will make it and without assistance, they wouldn’t travel for more than a week and less than 100 miles before succumbing to the elements. That would be fewer and less time/distance if you add in any hostile engagements or unconstrained rural communities…that would easily knock that back to 0.3% or about 3000 less healthy, lucky individuals barely standing on two feet.

Oh, and not everyone is fleeing in the same direction. Even with my estimate of 3000, if you live at least 30 miles from a large metropolitan area/city, your little rural haven may see a few dozen refugees at most and while they may be motivated enough to succeed “escape”, they won’t be in fighting shape.

ROCK6

O.K., I'll be the dick.
There aren't going to be any "refugees" after an EMP.   Civilization ends the day the grid goes down.  Exhausted, desperate, starving "people" will be virtually unrecognizable as human compared to before the event.  The sooner you come to terms with this new reality the better off you will be.  Just my take.  Might be worth considering or grounds for putting me on ignore.

Average urban/suburban people probably won't make far enough out to pose a first wave threat to rural folks plans.  Said another way their rate of travel will be zero.  They'll be dead.  It is the second wave that you need to worry about.  Once groups have formed and available resources gathered, the locust will flee the cities.   How fast and far they can travel will depend a lot on the severity of the event.  Running vehicles available, etc...?  Guess I'd consider this a known unknown .

Having survived the initial wave maybe you'll be thinking the worst is over.  Maybe you'll take a deep breath and rest on your laurels.  maybe you'll recognize this time for what it is and use it to organize and/or make improvements.  Either way you're not going to be as hard as the groups you'll be facing.  Maybe better fed, better rested but also untested.  I pray we never find out.

This nails it.

You guys need to look at the silver lining. Sure, 87% of the people in cities are out of shape.  BUT the hot women are all runners.  They can all run a 5k without breaking a sweat.  And most of them can do a half or whole marathon.  Sure, they’re used to water stations along the way, but they’ll survive.

And Maybe, just maybe, by the time they get 21 miles out of town, they won’t be communists anymore.  

Also they eat surprisingly little but you will need a large stash of espresso and pumpkin spice.  

Also, yeah cars will still work (even if you have to replace a fuse or two)

It's not a matter of just going for a stroll.   It's a matter of supplies.  No one for example can carry enough water to walk 25 miles in Texas during the summer. There are VERY few natural water sources and of course, there won't be any municipal supply.    Not that anyone is going to walk 25 miles in a straight line in any case. I think you guys really overstate the abilities of a lot of people. Heck, their SHOES won't last for 25 miles.

Take the last "Million Mom March" in Austin.  10 blocks. 78 degrees. There were 48 EMS calls for folks that fell out.  Whenever they have a 5K walk for some charity or the other, over a third never finish and end up catching a shuttle back to their car.

What most folks will do is walk just far enough to cluster around food and water sources. ( Lake, river, or Red Cross supply point)   There they will stay until they are driven to the next supply point by crime, disease or violence.  

Just like the Palestinians are doing right now.



For the posters claiming that illegal aliens do it, no they don't.  That's a media myth.  They ride buses and trains and get their supplies from various charities/governments, including ours.

It occurs to me that if the EMP is bad enough, information will be non-existent. In the cities, opportunistic a**holes will begin looting almost immediately. But, that happens in a normal power outage. Since cell and internet are likely to be down, most folks simply won't know the extent of the damage for a while, if ever. Somewhere around the one week time, folks will start figuring out that they are on their own. That's when the clock starts. People in the city that have working cars probably will have bailed and started driving away by day 3, assuming they have a clue enough to know to leave. That leaves the stranded in the cities which, by day 7 will have become utter chaos.

Will the city folks become like locusts/zombies and head out into the countryside? My suspicion is probably not. Many/most will continue to believe normalcy is another hour or two away until they simply give up and perish. Some will gather in the city center to demand "somebody" do something. Still, there will be small waves of folks that figured out they needed to bail. Folks with working cars will want to escape the looting. Folks on out outer perimeter of cities may start hoofing it to the nearest suburb to see if they can get food/water/etc.

All this is speculation about an event we hopefully never have to experience.

"Flyers and signs with directions to the FEMA camp" 30 miles away is a great idea.  I think I'll go ahead and work up a design.  

I agree.  Be a small percent that leave urban areas in the first few weeks.

Everyone I know that lives urban or suburban are absolutely petrified to walk up a dark country backwoods paved road on a good day let alone if shit hits the fan.  Other than the average hunter or hiker that gets out once in a while most folks don't like being in places without streetlights (never mind venturing up a dark 1/4 mile dark dirt driveway.)  Turn of their phone and/ or GPS and most won't choose to venture into the unknown until its too late.

I like the idea:  FEMA shelter located in: "name your city"

It's also a matter of who they are bringing with them; they'll be in family groups.  Are parents going to leave their kids behind?  How far can a child in elementary school walk in a day?  Are adults living near/with and caring for an elderly parent going to leave the parent behind?

Having several FEMA shelter signs/directions for all places away from my place seems like a great idea.  Pays to use cardstock as well so they don't tear off too easily when stapled to a pole.

Folks trying to care for and feed their children may be some of the most dangerous leaving the cities.  They'll kill you and your family and feel righteous about it since they are protecting their own children/family.

I think normalcy bias will keep lots of people from moving for a long time.  They will be out of water for several days before they start to move to look for better areas of resources.  The government will also likely be lying to people as to what to do while they steal the remaining resources.

Even once stuff is gone in cities, many people will stay there until it's too late and succumb before going a couple miles even.

Cell phones are relatively small and at least the screen itself with clock would work still and cell towers are more of an antenna and could potentially be unaffected. Smart watches would 99.9% work and older tube electronic devices would probably work as well. Typical wrist watches would also still work. Hair springs are fragile in older watches and the shock could break them but people have a lot of misconceptions of how EMPs works. They also would not have an effect on our bodies electrical systems. Roads are still roads and you can cover quite a bit of ground with your two feet.

If there's any emergency communications or broadcasting, I could guarantee the government would likely lie to the American people. They will either tell everyone to stay home and not travel, or travel to their nearest FEMA/emergency assistance location.

That normalcy bias is what I content will end many. Most don't have more than a week's worth of food in their pantries and likely only a few days of potable water (if the utilities are off). The longer they remain in place, the likelihood they have the energy or resources to travel several miles on foot is pretty minimal.


I think this is a very real threat assessment. Not many will survive larger populated areas, but those that do will have done so by being exceptionally ruthless and violent. If that “second wave” is organized enough to travel surrounding rural areas, they will be the biggest threat…they will have the motivation, the capability, and the hard-earned skills of post-apocalypse survival.

This is why I think it’s also important to not just stay hunkered down and bugged in, but once the survivors emerge in your area, start organizing and establishing communications and information sharing.

ROCK6

Just an observation.  If you are a fat survivalist, you probably aren't.

IDK, I see some fat dude waddling down the street 6 months after society collapses and I am going to leave that fucker alone.  God only knows what abilities the fat bastard has that let him survive so long and eat so well.

Probably has a solid recipe for human, dog, and cat based bbq

Well. Aren't y'all just little rays of sunshine, LOL.

Honestly, kudos. Preach it Brothers. Most people don't have a clue how hard such scenarios will be.

Sadly, I have to agree with you. Much would depend on working transportation. Road(s) condition. In a grid-down situation such as EMP natural or man-made it could be that dotgov will be as limited as most people. Or not. The national security apparatus is hardened against such events and one would think that ample supplies would have been set back. One would think. I don't think. I know that even if their emergency gennies run, how big is the supply? If there's no re-supply coming, all that fancy hardware, aircraft, ships, underground ICBM sites all that stuff quits.

Cities would be deathtraps. Too many people, too little resources. In my area, the desert is naturally dry. Water will be the most pressing thing followed by heat, if it is summer where temps climb well past three digits. The first to die will be those on meds, dependent on power to keep O2 machines going, CPAPs, etc. Then as the meds run out, those will die. The criminal element will also add to this toll as will accidents where significant medical assistance will be unavailable.

There will be no local assistance of any kind. Without a way to reach the population or function themselves without power, government would simply cease to exist. Police, fire and other services would do one of several things, stay as long as they could, leave to tend to their own families or, try to do both. While the criminal element tries to get as much as they want. And others. Y'all know who I mean. People will quickly turn to looting themselves to survive. I wouldn't care to speculate on how many would keep their civility or for how long. I'm generally a glass half empty kinda guy so that's not my forte. (Pessimist. Always expect the worst)

Oh, I'm not saying you can't ride it out. Given the right resources, choice of locale, the right PEOPLE you probably could. I'm just pointing out the obvious here. I see no need to offer my own solutions, ain't no better/worser than Y'alls. Just trying to keep on keepin' on. Doing my best to live right and not piss God off. Take care of me & mine best I can.

Last. "Thuh Gubbermint".
Personally, I think they like things like air conditioning and ice in their cocktails too much to do something like this. Accidental? Unintended consequences? Some crazy dude(s)? yup. But they know the risks (or should, dang people been wargaming crap like this for decades) Too many variables, too many ways for things to slip the reins and go careening down a slippery slope.

Of course, if one was willing to...wait awhile until all those pesky 'muricans died off, you could like, just waltz right on in....after.

I've experienced a number of temporary power outages as well as temporary comms outages. In 2017, I got sent to Puerto Rico to do emergency communications. FEMA wanted to tell the citizens where to get relief supplies (once the .mil stepped in and got them there). Problem was, no AM/FM/TV stations were functioning early on and even if they were, virtually nobody had any portable radios to hear them. I can absolutely believe that whatever .gov/.mil people and supplies will be reserved for themselves if we suffer a massive EMP outage. Further, if it's all across the country, there won't be a FEMA cadre riding to the rescue. Nothing will go anywhere. Each regional warehouse will likely disperse what they have to their region (assuming they can) and that will be it.

In 2021, when the Great Texas Deep Freeze hit, folks that needed more warmth could throw on an extra cat or blanket. Water, on the other hand, was problematic due to extremely low water pressure. Turns out, when you tell everybody to turn on *all* their faucets at a steady stream and flush toilets regularly to keep the sewers from freezing, you end up with water pressure at near zero. The city down here actually asked the Coast Guard to fly around to look for the massive water main break because that's what they assumed was causing the drastic water pressure loss. Now imagine if the problem wasn't stupidity in action but a lack of water pressure due to a lack of power for the pumping stations.

Cities are going to be deathtraps in the event of a devastating EMP. If such an event takes down all 3 CONUS grids, we're all in deep kimchi.

As long as we're on the subject, do these actually do anything to harden a vehicle against EMP?

EMP Shield

Some reviewers on Amazon are adamant that these are snake-oil.  I honestly have no idea.

For those with prepping knowledge, bugging out is a contingency, not your main plan.  Bugging out without a vehicle probably is a bad idea as well.  

In some kind of EMP scenario, I'd suspect the following would happen:

Those who are at home when it happens will stay at home.  Those at work will go home, by car or foot depending on if their vehicle works.  I'd suspect that would be the default decision making for most without communications.  Most would be hunkering down and trying desperately to gain information, probably via radio.  The government would be activating their continuity of government plans, which isn't much to the immediate benefit to the public.  Rule of law would be almost non-existent, but the public probably wouldn't be aware of that right away.  Police would largely go home to look after their own families.  

After a day or two, the realization will set it in that it is serious when those with hope realize they're on their own.  I'd expect looting to happen at this time with big box supermarkets and pharmacies going first.  Many would be armed, but I wouldn't expect much violence since the short lived abundance of supplies wouldn't give much reason to fight.  Many would probably go back home and hunker down since no other good option would exist.  Some who had a secondary location within driving or walking distance would try to go there.  A good amount of people would be on the move checking on relatives as well.  

After a week, it would probably get downright dangerous if the government didn't step in with security and assistance.  That could happen if it was regional and leadership was competent.  Neighbors would start stealing, begging, and being violent with those who had large hordes of supplies.  Anyone with a working vehicle would have to be very careful.  Criminals and opportunists would start setting up ambushes and preying on the public.  

Opinions vary, but I'd suspect that within a week without communications or utilities society would descent into anarchy.

I'd wager to say urbanites dont even have that! Theres is a very large segment of our society that eats out daily or simply stops daily by the grocery store on the way home from work, just to pick up exactly what is needed for dinner that night!

During the big Texas freeze, we had people fighting over bags of gas station Doritos by the afternoon of day two. By day three people were calling 911 begging for somebody to bring them food.

Police and fire were busy transporting the elderly to warming centers, going door to door looking for people freezing in nursing homes.

wow some really good responses! Thanks everyone. Lots to think about

still reading most of them now

25 miles on relatively flat ground isn't a hard walk at all.  You are, at best, 2-3 days away.  Even if cars aren't working, bicycles will work, and so "lead" elements of the refugee stream will likely be arriving from 25 miles away on the first day if the roads aren't closed.

The real question is how long would it take for anarchy to descend, and how would you even know about it if EMP took out comms and transportation?  Your first warning might be smoke or the glowing fires in the horizon, followed by the mass migration of people fleeing.

Then there's the question of what do you do with people that are simply fleeing with their families.  Do you force them back into a burning city?  Allow them to pass through?  Force them to go around?  Shoot them on sight?

25 miles is pretty brutal if you're trying to carry some supplies with you and you arent in good shape.  Most will probably have the foresight to bring water, which is very heavy.  Very few will want to do that on rough ground that will roll ankles.  A bicycle is better of course.  Realistically though, your best chance at bugging out is in a vehicle, notably a 4x4 truck or suv.  If you're in a city and it's super dangerous, maybe bugging out on foot is worth the risk.  

Anarchy wouldn't take too long I think.  The lack of information will be the most unsettling.  Someone posted above that any government communications will probably be overly optimistic and deceitful.  I'd agree with that because why wouldn't they?  It would be in their interest to delay anarchy through hope.  

I'd suspect that the attitude towards refugees would be that if you didn't know them before the event, you won't help them after.  Best bet would be to avoid them if possible.  If you had to interact, try to get some information out of them, tell them you're desperate yourself and someone has a contagious illness in your house, then point them 5 miles down the road to where  you heard the national guard was...  Sad as it is, that will be smarter than opening up your preps to random people.  You could bet more would show up after that.

Back right before the 2020 Lobby Day, I went on a hike with some Arfcom folks. It was a 6 mile hike and we had to do it in 2 hours with a pack. I was surprised I was able to do it and was doubly surprised I didn't sprain something and nothing hurt the next day. If I had to hike 25 miles, I could do it in a day but would probably be barely ambulatory the next.

The thing about the lack of information is that it keeps "hopeful" people from acting on what they are actually seeing. If by Day 3, nothing is happening and there's no info about when "normality" will return, smart folks will decide to GTFOD. The "hopeful" folks will sit tight expecting the .gov to ride in and provide food, water, etc. Fact is, in a nation-wide disaster like a real grid-down EMP, the .gov won't even have a plan developed for how to respond in 3 days. Further, a lot of local EOCs only have 3 days fuel for their generators and many don't have a satcom link (due to cost although Starlink may end up changing that). So, from the local perspective, they may only be getting info from fed .gov for a short time anyway. It's not clear what the .mil would do under such a circumstance as they would (in theory) be the only group in the country that could maintain itself for any length of time.

The other big unknown is if people started leaving the big cities, where would they head? Most people wouldn't know whether to head north, south, east, or west. Since desperate people become herd animals, they'll probably follow whoever is closest to them whichever way they decide to head. Maybe some folks have relatives that "live out in the country". So, they, along with a few dozen of their friends, might start hoofing it to the relative's place. By the time they get out of the city, there may be hundreds in the gaggle. Hope their relatives stocked up.

Heck.... Many of our larger cities are there now, with the lawlessness so rampant.....

Eh I’m definitely still a fan of being adjacent to large public land with a few assumptions.  1, the land is rugged or mountainous and 2 trail systems don’t go right up to your back door.  

It’s true you can’t control it (today) but you can’t control your neighbors in town or country either so not sure how not having neighbors today is worse than having average knucklehead neighbors.  

The biggest danger of being in the national forest is of course fire.  When people flee the cities and start cutting down trees to burn camp fires there’s a good chance they’re going to set the woods on fire.  That would be pretty catastrophic.  

But otherwise it’s overwhelmingly positive

The locusts arent going to make a beeline to your location. They'll stop to cull areas they encounter first. Like real locusts they'll move on when they've consumed the contents of the field they're currently in.

The US Army's official pace for dismounts is 2.2 miles per hour.  Remember that aplies to young, fit people with plenty of water and food.  Out of shape, non equipped civilians with little kids would do well to do half that...and in 3 days, they are non functional and will soon die of thirst..  My AO is a swamp, there is surface water everywhere, and I'm sure there will be a lot of the unprepared sick and dying of diarrhea.  

I'm hoping to get my neighbors on the same page ahead of time...

Several years ago, we sold a home and let the buyers take early possession.  The people we were buying our house did not allow us that, so we lived in a borrowed camper in our friend's yard.  This was for several weeks, the weather got cooler, we were still going to work and to school.  We also had our friend's house, so we had hot coffee, showers and a toilet.  I felt like a refugee, albeit a pampered one, and told myself I never want to be an actual refugee.  I say all this to say that if you hit the road, you better have a realistic destination in mind.

A second thought.  When it comes to masses on the move, you have to consider lines of drift.  It is not going to be everyone heading everywhere.  Factors might include local weather patterns, climate, locations of resources, and easiest routes of movement.

I think that the urge to leave urban areas will depend on how long the water comes and the sewer goes. If the cretins set fires and the fire departments are still working, then water supplies won't last long. When the toilets back into the bedroom, people will clear out. When there's no water to flush toilets, people will clear out. How far they get without water and without rule of law is a good question. People with working cars and somewhere to go (grandma's house in the country), will leave first.

In the USA, we mitigate disasters by moving assets from unaffected parts of the country. A Carrington event could affect the entire North American continent. An attack from a rogue nation of just two nuclear warheads, one each over the western and eastern US would affect all the USA and part of Canada. How do you repair utility transformers in a dark factory with no supply lines?

TLDR; the lack of clean water combined with poor sanitation will quickly kill those that aren’t taken out by other more immediate causes.  There will still be a small but persistent population that will be capable of covering quite long (continental) distances given enough time.


It seems to me the relatively short term limiting factor for people in a severe utility-down situation is clean water.

According to Montain, S. and Ely, M. in Chapter 7 of Military Quantitative Physiology: Problems and Concepts in Military Operational Medicine
https://medcoe.army.mil/borden-tb-mil-quantitative-physiology

One of the earliest qualitative signs of dehydration is the development of thirst.With approximately 2% body weight loss, vague discomfort develops, and the number of complaints increase. With additional water loss, soldiers can develop:
flushed skin,
heat oppression,
weariness,
sleepiness,
impatience, and
anorexia.

At 4% loss of body weight, soldiers display signs of apathy, and might complain of muscle fatigue and nausea.

At water deficits of 6% body weight and greater, soldiers will likely display
dizziness,
headache,
dyspnea,
tingling in limbs, and
very dry mouth.
They might present with indistinct speech and the inability to walk.

So for a 200 lb person 2%, 4% and 6% weight loss are 4, 8 and 12 lb of water respectively (or about 0.5, 1 and 1.5 gallons; 2, 3 and 4 liters).

Some additional findings reported from the above reference:

Dehydration in excess of 2% normal body mass has negative effects on morale and willingness to work. Comments from investigators working with soldiers during World War II illustrate how devastating dehydration can be (Figure 7-3). Adolph et al1 reported that, in dehydrated soldiers, “walking was mechanical, and a matter of will power” and that soldiers “threatened to quit unless given water.” Eichna and colleagues2 found that tasks became much more difficult, and “acclimatized subjects who had performed a given task easily, energetically, and cheerfully” were “reduced to apathetic, listless, plodding men straining to fin-
ish the same task.” More recently, Strydom et al50,51 reported that dehydrated men became lethargic and morose, and were aggressive and disobedient toward
their superiors.

Dehydration in excess of 2% body mass compromises physical performance. Exercise endurance time is shorter during both submaximal and maximal ex-
ercise, and less work is accomplished per unit of time when dehydrated beyond 2% body mass (∼1.5 L for a 70-kg soldier) in temperate and warmer environments. Detrimental effects of dehydration afflict large52–56 and small muscle mass activities.52,53,55,57–59 In contrast, dehydration has little effect on muscle strength, at least up to 5% loss of body weight.6 Evidence also indicates that somewhat greater dehydration is necessary be fore endurance performance is affected in cool/cold climates.60
Dehydration also reduces heat tolerance. In a 1992 study,61 scientists had subjects walk to voluntary exhaustion when either euhydrated or dehydrated (8%
of total body water). The experiments were designed so that the combined environment (Ta = 49°C, relative humidity = 20%) and exercise intensity (47% maximal oxygen) would not allow thermal equilibrium; thus, heat exhaustion eventually occurred. Dehydration re duced tolerance time from 121 minutes to 55 minutes; but, more importantly, core temperatures at exhaustion were approximately 0.4°C lower when subjects were dehydrated. These findings suggest that dehydration not only impairs exercise performance, but also reduces tolerance to heat strain.

Based on that I think that we would see desperate people moving that would pretty quickly (within a day) start utilizing surface and other water sources that would never be considered suitable in normal times.
While some would attempt to treat the water very few would be successful.  Perhaps those that had a water filter or treatment tablets from camping/hiking trips. Others might attempt to heat water to treat by boiling.
I don’t have direct data to support this one way or another but I think one could assume this is at less than 1% of the population of a given area.
For 2022 the NPS reported about 13 million overnight stays on about 312 million visits.  Those overnight stays include on-property lodging (like hotels and cabins), RVs, and backcountry camping.  The NPS reports a bit under 2 million backcountry stays for 2022.  Each person each night counts as a stay.  But if we just assume that each and every stay was a unique person on a uniques night in that year we are well under 1% of the US population per year.

I propose that, while on foot, people (in general, not the 0.001% person who rucks 100s of miles per week) are not going to be carrying heavy cooking equipment, water treatment materials, etc. very far but will be using expedient devices like carts, bicycles, etc. to carry more items farther.

If we accept for this exercise the premise that EMP will disable all forms of transportation that require moderately sophisticated electronics (think more than carburetor with plugs and toro) then I think we have to assume people that desire to move will be limited in methodologies.

Methods would move to things like bicycles, carts to haul goods, animals, etc.

I’d envision people moving from an extinguished source of supplies (shelter, water, food) to find additional supplies.  Dependent on location water could be relatively available but not in ready-to-drink condition (safe).  Water would be needed at a minimum level of about 3 liters (about 3 quarts) or so per day.

If we look at waterborne pathogens in the US we find that the top 5 (covering 97% of illnesses) domestically acquired waterborne diseases are
Otitis externa 65%
Norovirus infection 19%
Giardiasis 6%
Cryptosporidiosis 5%
Campylobacteriosis 2%

These cause very few deaths in the US each year.
These, other than Otitis external (swimmer’s ear), are much more likely to be a problem in a utility-down situation.

Norovirus:
Norovirus causes inflammation of the stomach or intestines. This is called acute gastroenteritis.
A person usually develops symptoms 12 to 48 hours after being exposed to norovirus. Most people with norovirus illness get better within 1 to 3 days, but they can still spread the virus for a few days after.
With support, even in a utility-down situation I think most people would recover from this, although the dehydration caused via diarrhea and/or vomiting wouldn’t be helpful.

Giardiasis:
Giardia can be found in every region of the United States and around the world. You can get giardiasis if you swallow Giardia germs. Some people with giardiasis have no symptoms at all. If signs and symptoms develop, they may vary and usually begin 1 to 2 weeks after becoming infected with Giardia.
Symptoms of giardiasis generally begin by having 2 to 5 loose stools per day, with progressively increasing fatigue. Other, less common symptoms include fever, itchy skin, hives, and swelling of the eyes and joints. Over time, giardiasis can also cause weight loss and keep the body from absorbing nutrients it needs, like fat, lactose, vitamin A, and vitamin B12. Some people with Giardia infections have no symptoms at all.
People with giardiasis will usually feel better and no longer have symptoms within 2 to 6 weeks. However, in some cases, symptoms may seem to be gone but will return after several days or weeks.
While this wouldn’t be immediately problematic I see this becoming a serious problem within a few weeks of utilities down.

Cryptosporidiosis:
Symptoms of cryptosporidiosis generally begin 2 to 10 days (average 7 days) after becoming infected with the parasite. The most common symptom of cryptosporidiosis is watery diarrhea.
Some people with Crypto will have no symptoms at all.
Symptoms usually last about 1 to 2 weeks (with a range of a few days to 4 or more weeks) in persons with healthy immune systems. Occasionally, people may experience a recurrence of symptoms after a brief period of recovery before the illness ends. Symptoms can come and go for up to 30 days.
Again, similar to Giardiasis I see this becoming a serious problem within a few weeks of utilities down.

Campylobacteriosis:
People with Campylobacter infection usually have diarrhea (often bloody), fever, and stomach cramps. Nausea and vomiting may accompany the diarrhea. These symptoms usually start 2 to 5 days after the person ingests Campylobacter and last about one week.
Sometimes Campylobacter infections cause complications, such as irritable bowel syndrome, temporary paralysis, and arthritis.
Again, similar to Giardiasis I see this becoming a serious problem within a few weeks of utilities down.

So, a lot has to happen for people in a full utility-down situation to decide to leave where they are.  They face a tremendous challenge of just basic needs in addition to actually moving any appreciable distance.

On the other hand we can look to the current situation in Sudan to try and study the problem further.  The UN estimates of about 50 million people in Sudan that about 1 million have been internally displaced or have left the country.  So that puts it at about 2%.  Photos online show refugees bunched around clean water sources and aid sources (things that will be in short supply during a widespread utility-down situation).

We know people can travel very long distances on foot given the resources and the time.  Clean water will be a big killer but won’t prevent all travel.  Shelter would be commonly available.  Food will be sparse and become hard to acquire in modern forms in relatively short time.

With all that said I’d estimate that (in a complete global scale grid-down situation) one could have 1 to 2% of the current population moving as refugees looking for resources (clean water, food, etc) over an exceedingly broad portion of the US as the population redistributes out of cities and becomes more centered around resource availability.

What do we do to be prepared for this?  No easy answers.

Presumably the amount of feces and decaying bodies in and around the water sources is going to increase geometrically and thus the impact of lack of proper sanitation will increase as well as nastier things than the ones mentioned above become more commonplace.

So protecting water sources from the hordes seems like a priority.

ETA, told you
https://x.com/ultradane/status/1738371349012533393?s=46&t=Sjepgi-iWV4rn_atOM0DJQ

One of the better conversations her on this subject...

That reminds me I really have to get that well and hand pump put in.

The poorly prepared will last about 10 days if that.  Those who don't get killed by the goblins will be shitting themselves to death from contaminated water.  Very few will make very far, I  can guarantee that few families still together will really understand what needs to be done to survive...  

Those in the megacity that stretches from northern VA to North of Boston will be screwed.   It's basically one enormous suburb from end to end with 70% or so of the US population.  I can picture miles of interstate clogged with stalled cars.   If you want an example, look what happens with numerous a hurricane warning and evacuation orders...

Correct- the vast majority of the densely populated areas will have people dying in their homes because they're unprepared to save themselves.  Street thugs will live longer than others due to their willingness to prey on others, but water will run out, or dysentery will set in.

As someone previously implied, the urban shitholes will see internecine gang violence worse than Baltimore after the Freddy Grey incident, where police stopped responding to calls and homicides went up 500% over the ensuing weeks. Once that thinning-out plays out, the survivors - who will be the most vicious killers and armed  -  will be leaving the cities in vehicles for rural areas in search of stockpiled food, clean water, more gas, etc. You can assume their vehicles will start out with full gas tanks and probably have extra gas in jerry cans.

Depending on the city (or cities) in proximity of travel toward your A/O, you should be able to figure out just how close a caravan of vehicles with full tanks (plus extra gas) will get to you before they'd run out and have to hoof it on foot.

Regardless, as suggested above, at each point along their route of travel these "looting-n-shooting" thug-caravans will encounter some level of armed resistance from rural groups of prepared defenders, and thus from sheer attrition over various firefights their numbers and fighting capability will be further thinned out. Some thugs will survive, escape, re-group and move on, but their numbers will continue to shrink as they move further into or around the countryside  - which will also be terrain they are unfamiliar with.

The further "out" you are from the likely path of travel of a convoy of cold, hungry, violent urbanites, the more time you'll have to prepare for the eventual encounter. So there really are no "safe" areas under the assumptions this scenario makes. They are only comparatively "safer" ones versus those that are "less safe" in relation to one's proximity to a highly populated urban center.

Grid-down actions

So for those people that are not able to (or choose not to) homestead what are the best courses of action in a severe, widespread (global or at least continental-level) grid-down event?

Let’s presume a suburban family of 4, has > 365 days of food stored for 4 adults (so can feed 8 adults for >180 days, etc.), ways to make clean water (e.g. filtration) and could well equip (arm, plus support items) 5 to 10 people.

We’ll presume that most vehicles continue to operate but it’s a bring what ya got situation with fuel (the fuel infrastructure is kaput so you aren’t getting more from the local gas station without a lot of creativity and once the gas station is empty there isn’t more getting delivered).

While the situation would clearly be different in many ways I still think this discussion can inform decision making for those in more rural areas, those in small towns and for those that are homesteading.

Some thoughts:

Information gathering:  It will be important to be able to gather widespread information to really understand the scale of the event so one can “over react” appropriately.  You definitely don’t want to under react (to nearly any event in my mind) as that will really put you on your heels for the long haul in case of a extremely severe event (doubtful it hurts much in what turns out to be a minor event).
Is this best accomplished with short wave, amateur radio (HF), other?  Even if there is basic communications infrastructure operating, in a grid down event it will die quickly once fuel supplies for backup generators, etc. are exhausted.
Let’s say you are able to gather information via radio.  How to put on a skeptical filter for the misinformation campaign (as described above)?  How to conduct your own misinformation campaign once you (think) you have a handle on the scale and magnitude of the situation?

Communications:
Local and global level:  For local anything more than just word of mouth (or flyers again as above) I don’t see any viable alternatives to handhelds (like amateur radio and GMRS, etc).  For global I think you are limited to HF (whether amateur, marine or similar).
In addition to what’s list above (flyers, pamphlets, radio) , what are some other ideas for redirecting people?

Shelter:  You’ve got a house, but now you don’t have grid electricity for cooling, heating, etc.
Let’s presume that you’ve got some degree of solar plus battery plus inverter system.  Maybe a basic system to keep devices charged and even to run your amateur radio setup.
Even in the case that you have a large hybrid solar and battery system that let’s you run your AC and that it wasn’t critically damaged during the grid failure.  Are you really going to want that AC unit making a bunch of noise when nearly everybody else has nothing of the sort?  There’s nothing quieter than an area during an extended power outage with little to no travel available (like the Feb 2021 winter storm that severely impacted parts of Texas).
I can’t imagine running a generator in this situation unless being very deliberate about the use of every last drop of fuel.
So, that said, do you use hammocks for sleeping?  Tents?  Where do you set them up?  What about biting insects?
In the winter maybe you’ve settled on wood heat.  Guess what can probably be smelled for miles around?  So what do you do?  Maybe you can run your heat pump off your solar battery system, but again you have the noise issue.
Some areas the winter is the worst part of the year for climate considerations, others it’s the summer, some are just right.

Water: Assume you have filtration that would last hundreds of people for multiple years.  What are good protocols for identifying surface water sources?  How to deal with surface water that’s been contaminated (hydrocarbons (oil), trash, dead animals, dead people, feces, etc)?
What are good protocols for approaching water, collecting the water, moving it to a more secure location?  What if the water is 100 yards away, 1/4 mile, 1 mile?

Sanitation:  Best practices for latrines?  Are the US military field manuals on this the current best practices?  Are there improvements that can be learned from third world areas?

Food:  Well, you’ve got food supplies for you and yours but they’re limited by what you could store ahead of time.  Maybe you have a hobby garden.  Perhaps you even went ahead and laid in supplies of seeds for planting in case of a disaster.
What seeds are you storing and planting for the long haul?
What time of year is it?
How are you preparing the soil?
Are you trying to irrigate?
Remember, fuel is at a premium (or non-existent at some point).  
Are you going to try and forage?  What’s left after the remainders of the hordes have moved like locusts across the land?  Maybe snaring and trapping small game to help supplement?
Perhaps some of your neighbors kept chickens and rabbits.  Are you able to acquire said animals or were they killed by starving people with no thought for the long-haul?  Even if you have them how do you feed them?  How do you keep them safe from other people and other predators?
Foraging through abandoned houses, will anything be left?
Even in modern times people have resorted to cannibalism, when is that a viable option?

Rules of engagement:
Follow your local law?  Fairly “liberal” in Texas for people and property, not so much in some other states.
SSS?
Neighbors? Friends? Females? Kids?  Starving? Thirsty?
Try and lay low to avoid any contact?  For how long?  What if you get discovered?

Other thoughts:
How to lay low?
How to “camouflage” your preparedness?
I can’t see it being a good idea to get into all-out gun battles.  More a “war” of attrition where hopefully you don’t have to get into open combat and people are thinned out by disease, starvation, etc. to a point where the land starts becoming sustaining again due to very low population density.
How long for the wildlife that made is past the “locusts” to rebound to where judicious harvesting can sustain a limited number of people?

What else?

Actual E1 EMP is pretty limited, i.e. "over a city". so unless its some major multi bomb attack the scenario is no one cares. E3 EMP is a bit different but won't really do shit to vehicles or normal electronics lest plugged in, but will damage the grid alot.

So rather prep for the 2nd.