Actually that Willow was doing very well for a long time and did provide shade for the Aniversary Pool. But that tree has been hammered by huge floods on at least a couple of differant occasions, like you see here:

http://www.flickr.com/photos/hotspringswizard/4181710403/sizes/o/in/photostream

Note that many of its branches are gone, being broke off from the flood waters. And in another big flood many years earlier nothing but the trunk was left up as high as where the branches are, the flood waters ripping the branches off. Then there have been the people at the springs that have at times cut branches off of it for some reason. Also the original dark dirt around it has been eroded away over the years. It seems to me there has been less water available to the roots because of recent repairs on the Aniversary pool. Water used to leak out of the pool through cracks down to the soil for that tree. I saw it a couple of weeks ago and for some reason this year it appears to be dead or dying.

The other cottonwoods that were planted many years ago up the beach above the Arizona Pool where doing great until the last few years when people started cutting down the lower branches and cutting on the trunks too. I saw on my last visit there were other trees cut down upstream from those Cottonwoods. Too bad people just can't leave the trees alone. I think we can safely say now that Arroyo Toad approval does not nesesarily mean that a Willow Tree will survive at DCHS :-)