346 dodge. DEBRIS CONTROL [Ch. 19 



of debris deposits in existing basins furnish a guide to debris-pro- 

 duction potentialities in adjacent areas that are entirely similar. How- 

 ever, no objective method exists for applying that knowledge to other 

 areas that differ somewhat in their geology, topography, and hydrology. 

 As in all engineering problems, overdesign leads to excessive cost, 

 and underdesign does not produce anticipated benefits and may be 

 dangerous. Thus an objective and practical method for appraisal of 

 debris-producing potentialities based on empirical but well-substanti- 

 ated factors that reflect the geologic, topographic, and hydrologic char- 

 acteristics of any area would have considerable value. 



Finally, the design of debris-control structures is open to consider- 

 able improvement. In general, inexpensive structures are frequently 

 dangerous, and safe structures are usually costly. A wide gap exists 

 between these extremes, a gap that could be closed by the development 

 of structures both inexpensive and safe. 



REFERENCES 



Alter, J. C. (1930). Mud floods in Utah: Monthly Weather Rev., vol. 58, 1930. 



Bailey, R. W., and Craddock, G. W. (1947). Watershed management for sedi- 

 ment control: Proceedings of Federal Inter-Agency Sedimentation Conference, 

 Denver, Colo., May 6-8, 1947, U. S. Bureau of Reclamation, Washington, D. C, 

 pp. 302-314. 



Dodge, B. H. (1947). Design and operation of debris basins: Proceedings of 

 Federal Inter-Agency Sedimentation Conference, Denver, Colo., May 6-8, 1947, 

 U. S. Bureau of Reclamation, Washington, D. C, pp. 274-293. 



Douma, J. H. (1947). Discussion of Dodge (1947) in same publication. 



Morris, B. T., and Johnson, D. C. (1943). Hydraulic design of drop structures 

 for gully control: Trans. Amer. Soc. Civil Engrs., vol. 69. 



Parsons, W. J., Jr. (1947). Discussion of Dodge (1947) in same publication. 



Woolley, R. R. (1946). Cloudburst floods in Utah: U. S. Geol. Survey, Water 

 Supply Paper 994, 120 pages. 



