Sharon welcomed the listeners and talked about the importance of water in life and life in water. She said that it is imperative for everyone to realize the importance of water, to drink plenty of water and to carry water with them if they are unsure of a water source. Dehydration, or lack of water, is out of control in our world and causes or contributes to ailments from allergies to obesity.
Guest: Gordon Grant, PhD
Gordon Grant, PhD (Corvallis, OR), Hydrologist, Oregon State University "The Rogue River, Boundary Springs and the High Cascades Aquifer"
Dr. Grant started out as a river guide on the Rogue River and eventually earned a PhD in Hydrology, a branch of Geology. He noted that the study of rivers, in Geology, is called "fluvial geomorphology," which is pretty much what he does.
The special interest of Dr. Grant is the High Cascades mountain range and its impact on water, especially the Rogue River. He says that the High Cascades are a very young range comprised entirely of volcanoes. The young lava rock is relatively soft, highly porous and is capable of holding a tremendous amount of water. Thus, while the region, at least on the ocean facing side, gets an extremely abundant two to three meters of rainfall annually, an unusually large percentage of the water is absorbed into the ground. Hence there is an abundance of springs and emerging aquifers.
One such emerging aquifer is Boundary Springs, on the northern edge of Crater Lake National Park. It is actually three springs and is the source of the main fork of the Rogue River. The Metolius River, in the mountains west of Bend, has a similarly configured origin. These types of river origins, where a full-below river suddenly emerges out of the ground, are very rare.
Boundary Springs comes from local ground water and has no connection to the water inside Crater Lake.
The High Cascades are the source of numerous rivers, including the Rogue, Willamette, Sacramento, Deschutes and Umpqua. Unlike other Western rivers, these do not dry up in late summer and fall. Snow melt also goes mainly into the ground and contributes very little to the annual flow.
The abundance and heavy year-round flow of High Cascades springs may be observed at Thousand Springs, on the Western boundary of Crater Lake National Park, and at the countless springs along the North Umpqua Trail that were opened when the trail was constructed.
Categories: Ecology and the environment; 2009