(Modified 29 Aug 2008)
Welcome to Unit 6 - Tearing Down Mountains II: Groundwater and Rivers
sgs.gov/lten/gallery4_files/image006.jpg Delta Queen, Tennessee River, 1945
National Water Quality Assessment Program (NAWQA) Tennessee River Basin Study, USGS
Left a big cliff in a landslide, Loosened by a rain and an earthquake, too
And I never lost one minute of sleepin', Worryin' 'bout that trench 'neath the ocean blue
River keep on movin', Bed load keep on groovin'
Rollin', rollin', rollin' with the river.
Shot through a braid in the mountains, Wrapped around a big old meander bend
But I cannot see the good side of the river, A reservoir trapped me away from my friend
River can't keep groovin' When dams stop the bedload movin'
Holdin', holdin', holdin' from the river.
If you go down to the river, Bet you're gonna see some houses too near
They might want to worry, storms are in a hurry, When the levees fail, there is something to fear
River will get movin', Wildness will be provin'
Rollin', rollin', ever-rollin' river.
"It was kind of solemn, drifting down the big, still river, laying on our backs, looking up at stars, and we
didn't even feel like talking aloud.
.." — Mark Train,
Adventures of Huckleberry Finn, Chapter 12.
Most rain is used by plants, but most of the rest soaks down through the Earth and flows slowly to
streams. Streams adjust to balance the water they receive through the ground, and the sediment they
receive from mass wasting. Dams stop sediment but release water, with large effects on ecosystems and
economies. The Colorado River is very different in Canyonlands above Glen Canyon Dam than in the
Grand Canyon below the dam. Big rivers build deltas that compact under their own weight, and flood
muds fill the space left; when humans hold rivers between levees and stop deposition of new mud, the
"protected" cities sink, as was demonstrated when the levees failed and New Orleans filled with water.
Water flowing through the ground dissolves caves in special rocks, providing beautiful places such as
Mammoth Cave, but construction headaches and short-circuit paths for groundwater pollution to affect
people; smaller spaces in rocks slow groundwater and pollution motion, protecting people for a while but
then complicating clean-up.
1. Textbook 6.1: Canyonlands National Park
(Modified 29 Sep 2008)