Archaeological sites deep within Grand Canyon National Park have been damaged, and lost in some cases, due to changes in the Colorado River caused by the construction of the Glen Canyon Dam.
Go with the FLOW: Fort Lewis College launches new river education program durangoherald.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from durangoherald.com Daily Mail and Mail on Sunday newspapers.
So why are worried about the bare sand, what’s happening to it?
The obvious one is really that when Glen Canyon Dam was completed in 1963 it formed a 700-foot high wall that creates Lake Powell upstream, and all of the sediment which would otherwise be transported through the Grand Canyon… is now sitting in Lake Powell. So Grand Canyon is really starved of sediment…. And the other reason that Glen Canyon Dam affects bare sediment is a more subtle story. That’s how flows have changed in the post dam period. In the pre-dam period, the river system is marked by really, really big spring and summer floods. … Following those floods the river would essentially go dry… It’ a desert river. That’s what we would expect. But today the flows through Grand Canyon are steady year round, so you’ve lost those large floods but importantly for bare sand you’ve lost those really low flows as well throughout the summer and fall months.