UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 832 



Contribution from the Bureau of Public Roads. 

 THOS. H. MACDONALD, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



June 7, 1920 



THE FLOW OF WATER IN DREDGED 

 DRAINAGE DITCHES 



THE RESULTS OF EXPERIMENTS TO DETERMINE 



THE ROUGHNESS COEFFICIENT, n, IN KUTTER'S 



FORMULA 



By 



C. E. RAMSER, Senior Drainage Engineer 



CONTENTS 



Introduction 



Field Measurements . . 



Computations 



Tabulated Results ........ 



Description of Channels 



Accuracy of Results ....*... 



Description of Experiments .."... 



Experiments In Lee County, Miss. . 



• Experiments in Bolivar County, Miss. 



Page 

 Description of Experiments— Continued 



Experiments in Western Tennessee. 24 



Experiments in Western Iowa . . 36 



Experiments in North Carolina . . 45 



Experiments in Florida 51 



Variation of n with Stage .... 58 



Application of Results 58 



Conclusions . 69 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1920 



