Shrinking Lake Powell Reveals Long-Lost Desert Wonderland - SLT

[hatrack]

BULLFROG -- "The philosophical quandary between half full or half empty need not be debated at Lake Powell this year as the enormous reservoir dips to 46 percent of capacity. (ed. - It's actually a shade under 42% of capacity as of 3/25/04) The upside of staring six years of drought in the face is that the basin that surrounds Lake Powell is more spectacular than it has been in more than a quarter-century, according to Glen Canyon Dam promoters and critics alike. The water hasn't been this low since the reservoir was filling in the mid-1970s.

EDIT

(ed. - hydrologist Brian) McInerney said a predicted runoff of 85 percent of normal for the Colorado River drainage has faded to less than 50 percent. March -- typically one of the snowiest months -- has turned out dry and exceptionally warm. The upshot is that the reservoir will gain several feet in depth until July, but then fall again to below the present level, unless weather patterns change. "It will take Lake Powell five years to fill with normal runoff," McInerney said.

EDIT

With the reservoir level at 3,584 feet elevation, Lake Powell is more than 100 feet below its capacity. Wonders such as the Cathedral in the Desert and Gregory Natural Bridge are among those now visible by boat for the first time since the 1970s, (ed. - Glen Canyon Institute founder Richard) Ingebretsen said. "Whether you like Powell or not, this is just spectacular," he said. "By revealing these features, we've been able to show people just how valuable Glen Canyon is."

For river runners, too, the low level is a rush because the lake no longer extends up the Colorado River into Cataract Canyon, Ingebretsen noted. "Thirty miles of river is back. Ten big rapids have returned."

EDIT

http://www.sltrib.com/2004/Mar/03282004/utah/151951.asp

[swinney]

1. Breaks my heart

Wish I had not read it. Such beautiful territory.

[HuckleB]

2. There was a fantastic piece in a recent Outside or Backpacker mag...

on Glen Canyon, showing incredible photos of hikers hitting the area. Absolutely amazing. I wish I had the time to head that way this year.

[NNadir]

3. I hate dams anyway.

Like many other resources, water is way underpriced with respect to its cost.

Neither are these systems sustainable. It changes not only the water flow, but the salt flows of the continent as well.

Glen Canyon, along with the Hetch Hetchy dam represent, IMO, two of the worst conceived dams in history.

[hatrack]

5. And speaking of sediment, check out this photograph (large graphic)

This is of Hite, at the head of the reservoir. As you scroll from left to right, look for a big rectangle about 40% across the image - that's the boat ramp, high and dry for nearly a year now.

And that island downstream? That's 40 years' worth of mud, now revealed by drought.

[NNadir]

6. Thanx from the picture.

The Canyon is magnficient, even with all that silt. Do you know how deep the lake was at the point of the photograph? Is that the dam shown on the extreme right?

[hatrack]

7. The reservoir was 50-60' deep in this area

The silt goes down about 150' from the top of the bar visible here to the original canyon floor, and what looks like the dam at far right is just the toe of the silt island - this is about 185 miles upstream from Glen Canyon Dam.

Unfortunately, I don't have any graphics on the San Juan River arm of the reservoir, since it carries (proportionally) an even heavier silt load than the Colorado - which is saying something.

This is one of the great sleeping problems that hardly anybody is talking about - reservoir sedimentation. It's about as unsexy and technical an issue as you can imagine, but cities like Phoenix, Tucson and Las Vegas are utterly dependent on reservoirs that are silting up quickly, at least in engineering terms. The Sacramento Bee had an excellent series on the long-term problems facing western water systems. I don't have the URL, but it's worth googling for - I think the title was "The Gathering Storm", or something like that. Check it out if you have time.

[NNadir]

8. Of course the other side of this silt deposition

is that it is not being deposited in estuaries and deltas. I don't know this for certain, but I would imagine that this is helping to lead to the decline of wetlands downstream. I know it has an effect on beach erosion (along with Greenhouse warming) I would presume.

It is nice to see that people have not given up yet on trying to get this horrible dam removed. It shouldn't have been built in the first place, but removing it, is the next best solution.

All this silt, of course, would only wind up behind the Hoover dam ultimately.

[hatrack]

10. Exactly so

You've probably heard about the subsidence problems facing the southern parishes in Lousiana. Many factors are in play forcing this phenomenon - rising sea levels, the criss-cross pattern of oil & gas canals throughout the delta, the burrowing habits of the nutria - to name a few.

But one big reason the Mississippi delta is disappearing is the loss of sediment from upstream. Without resupply of mud and silt, the delta was inevitably going to shrink, even without the problems mentioned briefly above. Lock and dam systems on the Mississippi capture some of the silt load, but the lion's share of the delta silt came from the Missouri system, a substantially muddier river than the Mississippi. Since the 1940s and 1950s, when the mainstem dams went up along the Missouri - Garrison, Fort Peck, Gavins Point and Oahe are the biggest ones - nearly all of the river's silt is piling up behind these structures, rather than flowing downstream to rebuild the delta.

The Colorado Delta, of course, died thirty years ago, but that was as much from the almost complete stoppage and diversion of the Colorado as from blocked sediment flows.

On edit: Oh, and by the way, I just went to the same website where I got the Hite photograph. According to the poster there, the NPS has moved dozens of houseboats that were docked about five miles south of Hite all the way down to Hall's Crossing, which is about 35 miles downlake. The NPS says that the frontal wave of the silt delta has already reached that far down from the abandoned boatramp, and is 160 feet deep at its face. That sure didn't take long!

[NNadir]

9. Gathering Storm series link.

Use the pop-up to Navigate the series.

Gathering Storm.

[NNadir]

4. The Glen Canyon Institute.

Here is a link to the organization dedicated to restoring the Colorado river above and below the disaster known as Lake Powell:

http://www.glencanyon.org/

[On the Road]

11. John McPhee's "Encounters with the Archdruid"

described a walking conversation with David Brower and the government official charged with creating Lake Powell -- while the lake was filling up. Very interesting. And the descriptions of the flooded habitats were amazing.