Supai Evacuated

[nonot]

The Redland Dam burst has caused Havasu Canyon to be evacuated. Hopefully everyone is getting out safely. Having visited earlier this year, I hope that the destruction is minimized and that the canyon and its residents are able to recover quickly.

I believe the town has been wiped out once before by another dam failure several decades ago.

[big_load]

Is that the same dam that broke a few years ago?

[base871]

from what ive read there has been no injuries. some damage to foot bridges and trails.

[PaleoRob]

Raft party was stranded overnight due to the flood washing their raft away after 8 inches of rain in a day. Wow!

[azbackpackr]

They have pretty big floods every year, and giant floods every decade or so. This one sounds like it's in the "giant" category!

[SuperstitionGuy]

Does anybody know what time of day the flood hit the village and campgrounds?

[chumley]

Well, it's difficult to discern anything from the information you read/see on the news. It's one of the most visited places in Arizona, you would think some news organization could find somebody who had actually been there to help contribute to the story. (I read in one story that "the campgrounds are 7 miles past the village" ... really? Does your newspaper not have access to Google Maps?) It probably doesn't help that the Havasupai Tribe is not known for their PR department, or even ability to simply answer the telephone for reservations.

Anyway, as best as I can tell, the Redland Dam burst at 6am on Sunday morning. However, the dam in not a particularly large structure, and it's demise was only a partial factor in the flooding. Friday and Saturday resulted in heavy thunderstorms which dropped 3, 6, or up to 10 inches (depending on what you read) of rain in the area. So, flash flooding was apparently already occurring in along Havasu Creek before the dam break added additional flow. Seems the evacuations began sometime Sunday morning.

In the meantime, I'm going to enjoy reading more stories in the New York Times about how a dam broke and flooded the Grand Canyon.

[chumley]

And because I was curious, and thought some of you might be too, here's the location of the dam. (I should qualify that with "I think" ... because the dam is not marked on the map, but "Redlands" Ranch is there, and looks to have some water retention capability on the topo map.)

Just doesn't look like the kind of structure that could result in a huge problem 35 miles away ... unless a lot of other rain/runoff was the primary problem.

35° 48.291 N
112° 25.913 W

[PaleoRob]

On KPHO 5 I saw a picture of Glen Canyon Dam next to the headline "dam burst flooding Grand Canyon." My parents called from California asking if we were okay with the dam break and the flooding Grand Canyon.

[SuperstitionGuy]

The Mississippi river here alongside where I live in Illinois is also rising. Maybe there is a relationship with the flooding of the Grand Canyon. Maybe I should call CNN and report it.

[big_load]

There was a little actual information in the NJ papers (Newark Star Ledger). Six local scouts and three leaders were at the campground and were evacuated by helicopter (minus their gear), reportedly after the dam failed, but before the water reached the village. They said there was no damage to structures prior to their departure. I don't know how long it would take water to go that distance, but it doesn't seem plausible that helicopters could be deployed that fast.

The Mississippi river here alongside where I live in Illinois is also rising. Maybe there is a relationship with the flooding of the Grand Canyon. Maybe I should call CNN and report it.

Some of my buddies in Oakville, IA, just allowed to see their flood-damaged home for the first time on Friday. A lot of the IA side south of there was once again spared by levee failures on the IL side. (Mrs. big_load is from Burlington, IA).

[nonot]

The chopper constantly runs in the canyon, it's likely they ordered people to hike out and had the least capable women and kids ride in the bird.

[big_load]

Yeah, the chopper seems omnipresent, but these were more than the usual. They were reported to be from the NPS, National Guard, and AZ Dept. of Public Safety and took "scores of people" to the hilltop, from where they were bused to a Red Cross shelter in Peach Springs. Based on other comments in the story, it sounds like the reaction was based more on the risk of catastrophe than its actual occurrence, although I don't mean to suggest that doing so was wrong.

[chumley]

There's a new article on azcentral that actually has some good information. First of all, the dam break was a completely erroneous story. Which makes sense if you look at the map I posted earlier. It was basically a cattle tank that ruptured and had no effect on the floods. The water was rising through Saturday night/Sunday morning due to the heavy rains, and evacuation of the campground was ordered by 5:30 am. And the helicopters were Blackhawks ... which indicates full-fledged evacuation, not just women and children! The article states that by 9am Sunday the creek was running 8 feet above normal. Now, I'm not going to ask exactly where they measure that, but if it's 8 feet above normal in the campground, then there's absolutely no dry ground except for the nasty outhouse at the upstream end of the campground. Either way, it's a lot of water. Check out the article on azcentral for the details.

[azdesertfather]

"The best news on Tuesday was that 11 hikers, unaccounted for since rainwaters flooded the village over the weekend, were safe."

"Ultimately, more than 250 were evacuated because of the flooding. On Tuesday afternoon, the 62-mile road from Route 66 to the rim overlooking Havasu Canyon reopened. The Red Cross also announced it would close its shelter this morning when residents would be allowed home. Those events added to the general relief that nobody was hurt or killed in the storm."

"But the mood was far from joyous. The beauty of that part of the Grand Canyon is an important part of the tribe's identity, and tourists coming to visit it are an important part of its economy. Billy Jack, with the Havasupai tourism office, said camping revenue alone generates $2 million for the tribe annually, and that, at best, it will be six months to a year before the area gets anywhere close to normal. 'I'm afraid it looks pretty grave,' Jack said. 'The whole area's unstable, especially toward the falls. The tourist dollars are really critical.'"

"The remoteness of Havasu Canyon, more than 250 miles from Phoenix, will also make repairing it a challenge. Getting workers and supplies to the rim of the Grand Canyon will be difficult; getting them to the bottom even more so. The only way to the village, one of the only places in the country where mail is still delivered by mule, is a 9-mile hike or a 10-minute helicopter ride. Some tribal leaders returned to the village on Tuesday. Although it remained off-limits to journalists, pictures of the devastation began to circulate by e-mail. The roots of trees along Havasu Creek in the village were left exposed by water. Mud was everywhere. But perhaps most significantly, parts of the trail leading from the village to the falls were simply gone."

(from azcentral)

[chumley]

The National Weather Service in Flagstaff has posted on their website an explanation of the weather which caused the flooding in Supai. I've copied it in its entirety, including the accompanying map.

Cataract Creek and Supai Flood - Aug 16-18, 2008

On the afternoons of August 15th-17th thunderstorms dropped heavy rain over the area between the city of Williams and the Grand Canyon, resulting in significant flooding on Cataract Creek and the Havasupai Reservation (village of Supai). Total rainfall for the period from Friday the 15th through Sunday the 17th was generally light in the Supai area, but as high as 4 to 6 inches within the Cataract Creek Drainage 20 to 40 miles southeast of Supai on the Coconino Plateau (as estimated by National Weather Service Doppler radar). As this water collected in the Cataract Creek drainage, it lead to significant flooding and the destruction of bridges and a campground in Supai Canyon, three homes destroyed near Supai Village, a small dam (Redlands Dam) breach on upper Cataract Creek, and hundreds of tourists and residents stranded in the Supai area. Multiple public safety agencies worked together to evacuate residents and tourists from the Supai area on Sunday and Monday (Aug 17th and 18th).

In the remote region of Coconino County from which Cataract Creek originates, accurate rain gauge data were unavailable. Radar estimated that scattered areas in the Cataract Creek watershed received 1 to 2.5 inches of rain on Friday, setting the stage for moderate to heavy flows on Cataract Creek. On Saturday, 1 to 3.5 inches of additional rain fell over the upper reaches of Cataract Creek. Another round of thunderstorms rolled through the area Sunday afternoon (well after the flood event began in the Supai area), producing additional (smaller) regions of 1 to 3 inch rainfalls on the drainage. Due to the localized and highly variable nature of rain associated with thunderstorms, the peak precipitation fell in slightly different locations of this drainage basin each of the three days, however a total of around 6 inches of rain fell at a few locations over the 3 day period, and many areas saw in excess of 3 inches over the period (three inches of rain represents more than a normal month's worth of precipitation in this area). See the image below which illustrates the location of the heaviest rain areas on each of these three days.

Runoff from Saturday's storms began to significantly impact Supai Village late on Saturday night (5 to 9 hours after the rain fell upstream on the Coconino Plateau). By early Sunday morning, severe flooding was occuring in the Supai area. Redlands Dam, a small holding pond (about 45 to 50 river miles upstream from Supai Village) failed at approximately 6:00 AM on Sunday morning, but likely added little to the enhanced flows on the stream.

On Sunday afternoon and evening additional thunderstorms moved through the upper Cataract Creek watershed, dropping up to 3 inches of additional precipitation. This rainfall washed out another road west of Valle, and kept the flood waters high in the Supai area through Monday, August 18.

[azdesertfather]

so it sounds like the actual flash flood came from when the Redlands Dam was breached?

[chumley]

no, actually, it says the dam failure "added little to the enhanced flows on the stream"

[big_load]

That's consistent with what the rescued Scouts said, too. The water had been gradually rising even before they arrived at Supai. They were directed from the start to camp on higher ground (perhaps it was the area uphill from the campground to the east) and were evacuated from there when the water continued rising even to that level. As the story noted, that's a lot of rain in a short period of time in a compact drainage system.

[azbackpackr]

If there is an actual flood, it would be hard to hike out. A great deal of the trail is within the flood zone, both upstream and downstream from Supai village, so I think one would either seek high ground or take the helicopter. There are other ways to the rim, of course, but I expect most did not use those ways.

National Guard is nearby at Bellemont and could have been deployed quickly from there, I think.

Interesting to read that there is now a great deal of unstable ground, and that it will take a long time to rebuild the trail so that it's safe again. I would imagine that right near the areas of Navajo and Havasu Falls the trailbed could be totally washed away. If you'll recall, there used to be signs right by Navajo Falls that said "unstable ground." One time when I went it was only a few months after a very bad flood. Every time I go there it looks different from the time before, though!