Due to the extreme heat and dryness of The Grand Canyon, you will need to plan ahead and take plenty of water with you.
It will take three times longer to get back up the trail than it did to go down!
The only trail that has water is the Bright Angel trail. The South Kaibab trail has no water. Even if you are on the Bright Angel trail, you need to take water with you. It can take a long time to get to the next rest house were there is water.
I have seen a lot of people that became too hot after hiking in the canyon. I really felt sorry for them. They were in rough shape. Don't get caught without water or you will pay the price too.
If you want to go walking in The Grand Canyon follow the Park Ranger's advice notices. Remember that in the summer the inner canyon temperatures often go over 100 degrees and so carry plenty of water and high-energy foods. Also remember that whilst a descent into the valley may only take four or five hours it will take you more than twice that to get back out. Never walk alone and always inform someone of your plans.
As the park notice in the pic shows - it doesn't matter who you are or how healthy, if you are not adequately prepared the Canyon can kill!
Unlike the Bright Angel Trail, there is no water along the Kaibab Trail. You can get water only at the trailhead and once you have reached the Colorado river. This is the price you pay for the presumably better view.
Truly yours almost passed out with dehydration because he had only half a litre of water for the whole day (in mid June). This was an absolutely reckless thing to do. What is more, there is no shade along the trail once the sun is high in the sky. The park rangers recommend that you drink 1 litre of water for each hour you spend in the Canyon. While this may sound far-fetched, once you are down there you realize that they are absolutely right. If you have enough water and are reasonably fit, you are OK.
If you are like me, you will be surprised to learn that the elevation at the south rim is about 7,000 feet above sea level. This means the air is thin and dry so you need to drink a lot more water than you think. Particularly if you are here in the warm or hot time (it can get to 100 degrees F as early as May), this is critical. Also, salty snacks on a regular basis will keep you from succumbing to exhaustion. One ranger told us he recommends drinking a quart or liter of water every half hour. You also need to plan how far you can comfortably walk. No one should try to hike to the bottom and back in one day. It is reported that about 250 times a year people who have tried have to be rescued and the majority of them are healthy males between the ages of 18 and 40.
Do hike down the trail, even if it is just a short hike. Of the almost 5 million visitors a year only about 5% ever get below the rim (1% actually get to the bottom of the canyon). Be one of the few but be cautious.
The Grand Canyon can be deceptively hot and dry. Cooler temperatures (relatively speaking, here) at the top do not mean cooler temperatures inside the canyon. Some of the trails (Bright Angel) provide water at certain points, but you should still bring plenty of your own or at least containers to transport water.
You don't want to be caught without water.
We saw many foreigners, unfamiliar with the desert environment or expecting water to be available asking and even begging people for water as they didn't bring their own.
You don't want to be caught in this dry and hot environment without it.
The Kaibab trail and even Bright Angel after a certain point don't provide water.
Look for a headache, possible nausea and dark yellow urine as signs of dehydration.
I guess what I'm trying to say is... same as any outdoor hiking environment, bring water.
The amount of water you bring depends on your fitness level- both in how much you can carry and how much you lose to sweating- your planned route and time out -both time of day and length of excursion- and the time of year- obviously summer will be hot. Each person should have a good supply (a few liters, at least, especially on trails where water isn't provided). Try any local grocery store for the better prices, since the tourist places will have higher pricing.
Stay away from carbonated soft drinks, high-sugar drinks, coffee and alcohol... at least until you get back.
WATER! If you plan on hiking into the canyon, bring LOTS AND LOTS of water. You could seriously get very sick or die without it... it's a desert within the canyon, and if it's hot enough, there'll be rangers not letting you onto the trail if you don't have enough water. There are a couple places on the Bright Angel Trail to fill up with water, which is nice. Anyway, I'm not sure on the statistics, but I think it's at least a gallon per person per day... check www.nps.gov for more info at the Grand Canyon page.
Walking in the Canyon is tiring especially in the desert sun. Make sure to bring plenty of water n order to avoid dehydration. We brought two refillable water bottles that we refilled at water fountains throughout the day.
If your going to descent into the canyon, be sure to take enough water with you. After Indian Gardens there are no point where you can refill a bottle and even there the watersupply is not that steady. Going down to the riverside means hours walking in a mostly dry and hot environment. The canyon has it's own climat one can say.
You may have heard that you need to keep your salt levels up when it's hot. A quote from one of the Rangers I talked to: 'If you eat salt tablets down there, you'll come out in a body bag'... Moral of the story: don't take salt supplements.