Daily water need

Depends on when you’re leaving and how long it’ll take you to hike the 13 miles. If you’re leaving late afternoon and returning early morning, I’d probably take 3 liters. If you’re going to be gone all day both days, that would be a different story. Haven’t done a hike like that where I couldn’t cache water.

I love water! I would carry 4 liters for something like this. And i would tank up extra .. for 2 camels at trailhead!

I drink about 3 liters per day while backpacking 15-20 miles per day in moderate weather. Takes another liter to get through one night, between cooking, cleaning, and tea. So I would normally start with 7 liters for a dry, two-day trip like yours.

So now add fudge factors. Low 80s F during the day – add some water, but depends on humidity, shade, elevation gain, and high elevation (lose more through breathing).

How long it stays hot matters, too. Sometimes you get a distinct peak high temperature with cooler temps most of the day. Other times it heats up shortly after sunrise, stays hot, and doesn’t cool down until sunset. Usually it’s somewhere in between.

No water for meals or cleanup – drop about 3/4 liter. Willing to end the trip with dry mouth – drop another liter. But always keep some in reserve for emergencies like unexpected delays or wound cleaning.

Net for me – I might start with 5 liters. Plus all your other tricks.

Over-cameling at the trailhead just means more urination sooner, so don’t overdo it.

Don’t ignore electrolytes – at least in your food, even on short water rations. Everybody’s different on those.

Consider a slower pace, to reduce sweating and heavy breathing. And less shouting “Hey Bear” every couple of minutes, so maybe bear bells?

Try for an early start on both days, to reduce heat stress. Afternoon siesta in the shade?

— Rex

The typical rule of thumb I thought was 1 liter for every 5 miles. If there is no water and it is 26 miles + water for food, then the calculation would be 5 liters for just completing the 26 miles. Half a liter for dinner + half a liter for brushing teeth etc. So, it would be 6 liters at least. Now, if you start real early when it is cooler, you typically do not consume that much water. What I have noticed is that I do not consume more than a liter from 6:30 AM to 11 AM (assume 10 miles in that span) or so in the Sierras or Colorado etc. So you can take that into account as well and carry 1 liter less perhaps for each 10 miles. You maybe able to get away in 4 liters. Good to be conservative and carry 5 liters to 6 liters. Also since it is just a overnight and you are going to hydrate before starting, it is not a big deal even if you get it wrong. Just have lots of water in your car so that you can drink after your trip.

I would take about the same as Rex.

You say: “On normal non-hiking days I drink a lot of water.”  If you are consuming a total of 3 liters total liquids including those consumed in food in a normal non hiking day, I would think 4 to 5 liters might  not be enough for backpacking in 80 degree whether.

Do you have the ability to measure your daily consumption?

Dehydration can hit you quite hard if the weather is hotter than forecast and you are short on water.

I have never really understood the so many miles per liter statements.  Not all miles and days are equal.  I do a lot of desert/dry hiking and it always comes down to 4-5 liters a day, 5 if warmer.  So as someone said it depends on when you start and when you get back.  My basic rule of thumb for warm weather is 1 liter for breakfast, 1 for the morning, 1 for lunch, 1 for afternoon and one for dinner; no washing up etc.  So similar to Rex and others, 3 during the day and 1 or 2 for meals depending.

The electrolytes can help, I have found something Nuun tablets do seem to help “stretch” the water.

As to cameling up, it is now well known that any more than a half a liter right before is just a waste as you will just pee the excess out and will have just carried it the whole time, internally.

5 L per day?
That is a huge amount of water! And probably seriously excessive imho.
For a high camp (ie NO water up there), I allow 6 L for the TWO of us (wife & me). That covers drinking on the way up, dinner, breakfast and usually morning tea as well. Plus washing up.

Cheers

I have never really hiked hard or long miles in a desert. I can’t imagine drinking 5 liters a day in my environment, but maybe in a desert?

Thanks for all the input, looks like there’s a wide variance. I’m going to go for 4.5 liters for the two days, and drink a bit before leaving in the morning. If the mosquitoes drink all my blood, I could be in trouble.

@ Karen… You will survive!!

5 L per day?
That is a huge amount of water! And probably seriously excessive imho.
For a high camp (ie NO water up there), I allow 6 L for the TWO of us (wife & me). That covers drinking on the way up, dinner, breakfast and usually morning tea as well. Plus washing up.

Roger you are scrawnier and tougher than me but you are not far off my estimate of 4 a day depending on when you leave and get back to water.  I have found, for me, 5 for really hot weather is about right to be comfortable and not excessive.

Cheers

Yeah, for really hot weather all bets are off. There comes a temperature where you start sweating a lot, and then you may need to drink a bit. What temperature depends on your condition: we always find it takes a few weeks to adapt once the hot weather hits.

Cheers
PS: not sure about the ‘scrawny’ bit. I wish.

I’d go with 5 L for the entire trip, based on your description.  The difference between 4.5 L and 5 L is one pound, and if you get delayed/injured, etc, that extra .5 L could come in very handy.  When it comes to water, a little too much is always better than coming up short, IME/IMO.  You might want to consider taking a couple of packets of electrolytes, too, or even half an ounce of plain old table salt (NaCl) and a few magnesium tablets, just in case you start cramping.  Worst case, you end up carrying an extra pound of water and a few grams of electrolytes.  Far better than ending up dehydrated and cramping.

26 miles round trip, plus water needs for camping overnight?  And no gauranteed water supply along the way nor at camp?

I’d not only camel up at the trailhead but be sipping an additional liter on the drive to the trailhead.

And then, much as I hate to carry water, I’d bring 5 liters – 2 in, 2 out, 1 for at camp (with a menu that requires little or no water to prepare).

Half way in, I’d look for a spot to stash the 5th liter and avoid carrying it the last half, round trip, for a savings of 13 miles x 2 pounds = 26 pound-miles.

I’d also wear light-colored clothing, hike earlier in the day (advanced cultures take seistas in the hottest part of the day) and strongly consider a Chrome Dome or similar – I feel 10-15F cooler underneath a sunbrella.

a spot to stash the 5th liter
Inside the base of a burnt-out gum tree. It stayed ‘slightly’ cool.

Cheers

I would bring 6L.  2.5L for the hiking, 1L for meals.

My typical water consumption when backpacking (3mph with moderate elevation gain, slower when steep)  is 1L for every three hours when it’s 30-60F, around 1L for every 1.5-2 hours 60-80F, and 1L every hour when it’s more than 80F.  When engaging in vigorous activities such as running I use around 3x my normal rate.

I determined my water needs by doing a number of tests where I weighed myself and the water I was carrying, engaged in activities, and then weighing myself and the remaining water at the end,  also paying attention to  my level of thirst.  You’re milage will vary.  I always encourage people to run experiments like what I did.

I ran out of water once, and vowed never again. What you need to carry depends on your metabolism and climate etc. Only long experience and careful accounting can tell. In the meantime, bring extra and don’t rely on getting back according to plan.

My consistent consumption for desert hiking in mild temperatures (perfect temps to slightly cool to a bit warm) on low-mileage cross-country trips is 3 liters per 24 hours (and I don’t cook). When it warms, it goes to 4 liters. When it’s just plain hot all the time, 6 liters or even up to 8 (yes, Roger). I recall a 15-mile dayhike in a hot canyon during which I drank three gallons.

I’m talking consumption, not what you should carry. In remote waterless places your water is your only insurance. Twist an ankle and see how much longer it takes you to get home. Break a leg, and you’d better hope you have enough excess to survive while waiting for SAR to arrive. If your backup plan is to have someone at home call for help if you are late returning, that could become days if your injury happens early in your trip.  (I generally hike alone. Now I carry a PLB, but it may not work in a canyon, and I shouldn’t be gauging my water carry according to reliance on technology.)

This spring I started a trip with a 58 lb pack, which included five full days of food and five full days of water (that’s why I don’t use an ultralight backpack). I’m not saying I went far or that it’s fun in those early days, but it’s always great to be out there.

Roger and Randolph: I’ve gone through a (wimpy 4-liter US) gallon in 3 hours and wanted more (hiking 5,000 feet up in the Grand Canyon on a summer day).

And, Karen, factor in how un-acclimatized you’ll be.  If I stepped off the plane from Alaska and started hiking in the desert, I couldn’t go as far nor as fast as I could after I’d been there several days.  And I’d need more water.  It’s not as bad, for me, in a dry heat, as when it’s hot and muggy, but still – I have more fun showing off at GCNP wearing shorts in January when it’s a balmy 25F than in July when it’s 80F on the Rim and 110F in the Inner Canyon and I’m carrying extra water to wet myself down.

When it’s just plain hot all the time, 6 liters or even up to 8 (yes, Roger). I recall a 15-mile dayhike in a hot canyon during which I drank three gallons.
Well, I did say that once it gets really hot, ‘all bets are off’.

Cheers

I’d find another hike….I hate carrying water.

Karen,

Your hike, for me, I’d want about 2 gallons / 8 liters.  Also one “in the tank” and one in the truck for when I get off the trail.  13 miles for me with a pack is about 6 hours of trail time.  At 80 degrees “conserving” I’ll drink at least 1/2 liter per hour.  So 3-4 liters will get me to camp.  Dinner + breakfast I’ll drink another 1-2l, and then will want 2-3l for the hike out.

My reference is a November thru-hike of the Tonto Trail, Grand Canyon.  I was told not to expect water until half-way through day 3 of my hike.  I limited myself to one gallon over a 16 mile first day and was fumbling and bumbling by the time I got into camp, and felt like crap.  Temps were upper 70’s.  So glad I found the seep up canyon was beginning to pool.  I drank another gallon between while waiting for dinner to cook, in my dinner, and before bed.  It took than “in camp” gallon to feel good again.  So optimal for me would be about 2 gallons per day.  That said, if there is no water on route I am sure I could make 2 gallons for the weekend hike work, it just wouldn’t be optimal for me.

We are all a bit different in how much discomfort we will tolerate, but my reference says 2 plus/minus maybe 1/2 gallon for your hike.

So post-trip report on the water thing. It was hot, more strenuous than I anticipated, but not bad. I brought 4.5 liters. As we hiked in the 13 miles, we found puddles on the trail that could be filtered, although muddy. Toward mile 11 we found some really decent pools of water that were clear on top (until the dog tromped through!). We were all still good on water though so we marked the waypoint and continued on. We stayed at a remote cabin with no water source, but discovered that the cabin owner had left a pile of lumber, covered with a tarp. Trapped on top of the tarp in a little depression was about another gallon of nice clear water! It had been rainy so the water was new with only a few little buggies in it.

I used use my steripen on about a liter of the tarp water, before setting out for the return journey, even though I still had most of my camelbak and another half liter. When I returned home I still had about a liter in the camelbak, so even though I had taken some additional water, the 4.5 liters estimate was about right. In total I probably used 5 liters and was fully hydrated when we got the vehicle, where we had stashed a 5 gallon jug.

Really lovely trek. Sometimes even just an overnight can feel like a real vacation. Here is the view from the cabin window at 3am.

Nice shot there!  Glad it worked out for you.

Just for comparison sake I once did a 7 mile day hike in Joshua Tree NP in August.  Desert in peak summer. We started at about 9:30 am, when temp was mid 80s F and ended around noon, temp was well over 100 F.  HOT!  I drank almost 5 liters of water.

It was the first time I realized how truly easy it is to die in the desert.  Never again.  Ever.  It was a short hike, but the dumbest I’ve ever attempted.  I remember being only 1 mile away from my car and out of water, briefly thinking what if I don’t make it.

The night before was the coolest meteor shower (perseid) i’ve ever seen though.

When I go to Joshua tree for 1 overnight trup now, not summer, I bring 7 liters of water.  I usually have 2 left over, but we only hike about 10 miles total.. Maybe I just drink a lot.

Just did a similar mileage hike but at elevation, 10K  and with gain 4K and 2.6K. Used 4 liters per day. That’s with 1/3 to 1/2 liter for coffee each day and 6oz for soup. BUT I had access to water.

I did a 22 mile, 7K foot gain overnight in the desert-temps 50F low/85F high not long ago and I took 10L and was really dehydrated when I got back. That hike is totally exposed and about as dry as it gets in the states. I could have taken another 2L but my back couldn’t take it. A smaller person on the hike thought he could get by with 6L and ran out, luckily found some cached water from 2007 that was abandoned. His take was he also should have brought 10L.