Grand Canyon High-Flow Release of Colorado River

Any idea if they allow rafting trips during these events? I'd guess a lot of the rapids, like Lava, would be easier in higher water conditions. Although the mile-by-mile guidebooks would be fairly useless in such atypical conditions.

“The flooding is expected to reduce the number of campsites available along the Colorado river.”

…. during the high flow.

Four days of 37,500 cfs, is to rebuild sand bar camping sites. Total time is 5 days

Trips go as planned.

GC NP Information

David… read the book The Emerald Mild.
Some rapids are worse at high flow… MUCH MUCH MUCH worse… killers.

billy

13 years ago the standard Grand Canyon river guidebooks rated major rapids at a variety of flows, some pretty high. My books are buried in the basement or I'd confirm.

I've talked to guides who ran the river in the early 1980s when it ran 50,000 to 100,000 CFS for extended periods. They had no guidance!

They were forced to camp so high that they found the trash from early (pre-Glen Canyon Damn) river runners who routinely boated on flood flows. The average pre-dam flood through the Grand Canyon was roughly 100,000 CFS.

A well-known Colorado River scientist once said "45,000 CFS is a pretty wimpy flood," referring to one of the first high-flow experiments.

Every rapid responds differently to lower or higher flows than "normal". Some get harder, some get easier, some are unrecognizable. At extremely high flows, some gnarly rapids appear where none was seen at lower flows. This is true on every river, not just the Colorado through Grand Canyon.

One one trip we scouted Horn Creek, checked the guidebook, and read "Not recommended below 8,000 CFS".

"What's the flow?" "About 5,000 for the next week." (Another experiment in progress.) "Now what?"

As for campsites: during high flows, low-lying campsites will be underwater. After high flows, some campsites will be washed away (erosion), others will get bigger (deposition). Hard to predict, that's why they're called experiments.

— Rex

I did the Royal Arch route years ago during a release which peaked at 55,000 cfs. The river level stretch was quite a bit harder due to being forced up into the boulders, but seeing and listening to the river at that level was pretty cool.

Sad to say there are almost no (or just none?) big rivers in the lower 48 which we'll ever see at true flood. Packrafting across the Copper in AK at ~150,000 cfs? An impressive and intimidating experience. The sediment was so loud against the tubes I thought my boat might erode away from under me.

>"the Copper in AK at ~150,000 cfs"

I wear a PFD when I'm on the SHORES of the Copper River.

Really.

I haven’t been to Alaska since 1991. I still remember the Copper River.

HJ
Adventures in Stoving
Hikin Jim’s Blog

It's pretty entertaining to cross an eddy line and go from 1 mph to 12.