If you're hoping to visit the Grand Canyon in the next few days, better postpone your trip - unless you have an ark.

Grand Canyon FloodIt's not exactly biblical-type of flooding. It won't wash away livestock, villages and people, but today's man-made flood will hopefully wash away some of the damage that was done when the Glen Canyon Dam was built in 1963.

Early this morning, 2 giant steel tubes began shooting 300,000 gallons of water into the canyon from the base of the dam - enough to fill the Empire State Building in 20 minutes. Officials have high hopes for this flood, including a hearty stirring up of the life-giving sediment on the floor of the canyon.

"This gives you a glimpse of what nature has been doing for millions of years, cutting through and creating this magnificent canyon," Secretary of the Interior Dirk Kempthorne said after he pulled the lever to release the water into the canyon.

To see the amazing amount of water pumped into the canyon, check out the slide show on the Washington Post. Be sure to scroll through to the last picture!

The 45-year-old dam traps the sediment that once flowed freely through the canyon, and is directly responsible for the extinction of 4 types of fish and putting an additional 2 on an endangered list.

Prior to the dam, a strong monsoon season washed sand and sediment to the Paria and Little Colorado rivers, which then emptied into the Colorado below the dam. Officials hope the sudden increase in flow (4-5 times the normal amount for this time of year) will create sandbars and natural habitats for native fish.

Not everyone agrees artificially flooding the dam is a good idea though. Environmentalists argue that flood just puts the health of the canyon at further risk by too much at once. They believe permanently altering the flow of water in a way that more closely mimics nature is a smarter approach.

"They're trying to make it appear that they're doing something beneficial when they're just doing it for appearances," said Nikolai Lash, senior program director for the Grand Canyon Trust. "It's being manipulated to be a 'one and done,' even though we know that doesn't work."

The dam has been flooded twice previously in 1996 and 2004.

If you're a rafter, fisher, hiker or plan to visit the area for any reason in the next week, call the Grand Canyon National Park's River Permits Office at 1-800-959-9164. For additional information on how the high-flow event may affect your stay, visit USGS.