With this final sentence in his book A View of the River, Dr. Leopold elegantly summarizes the underlying philosophy of Natural Channel Design.  Since a river channel reflects the environment in which it developed, the channel itself provides valuable information about the way in which that particular river functions. 

Rather than relying on laboratory data and theoretical relationships, Leopold and researchers such as Dr. David Rosgen used field data to develop mathematical relationships between real-world stream parameters.  Dr. Rosgen integrated these relationships into a stream classification system that allows river managers to use the stream itself as a guide for assessment and restoration of river channels.  He continues to refine restoration techniques that use natural materials (such as boulders and willows) to mimic nature's most healthy river dynamics. 

Natural Channel Design projects must begin with high quality data.  For this reason, Cheryl Harrelson et. al. described stream mapping techniques in “Stream Channel Reference Sites:  An Illustrated Guide to Field Technique.”  Only after this data has been obtained and analyzed does it become possible to define, assess and plan for the long-term stability of the river.

The final result is a river that self-maintains its channel features by transporting its water and sediment, provides a variety of habitat, pleases the eye, and functions as a stable natural system.

Additional sources for more information on Natural Channel Design concepts:

"Stream Channel Reference Sites: An Illustrated Guide to Field Technique" by Cheryl Harrelson, CL Rawlins and John P. Potyondy is available from the US Forest Service Stream Team. (5 MB PDF file).
 

Dr. David Rosgen's publications and river short course schedules are available from Wildland Hydrology, Inc.
 

Books by Dr. Luna B. Leopold:

Fluvial Processes in Geomorphology, Luna B. Leopold, M. Gordon Wolman, and John P. Miller, Dover Publications, 1995.

Mountains and Mesas: The Northern Rockies and the Colorado Plateau, Pete Bengeyfield, Alice Bengeyfield and Luna B. Leopold,  Northland Pub., 1996.

Round River: From the Journals of Aldo Leopold, Aldo Leopold, Luna B. Leopold and Mary A. Shafer, Northword Pr; 2nd edition, 1991.

The Colorado River Region and John Wesley Powell (Geological Survey Professional Paper 669), Mary C. Rabbitt, Edwin D. McKee, Charles B. Hunt and Luna B. Leopold, University Press of the Pacific, 2001.

View of the River, Luna B. Leopold, Harvard University Press, 1994.

Water in Environmental Planning, Thomas Dunne and Luna B Leopold, W. H. Freeman, 1978.

Water, Rivers and Creeks, Luna B. Leopold, University Science Books, 1997.

Water: A Primer, Luna B. Leopold, W H Freeman & Co., 1974.