RESULTS 



The amount of sediment accumulated in the dams that could be attributed solely to 

 road erosion was determined by comparing data on the three watersheds to data of the 

 same type collected on five contiguous and similar but unroaded watersheds (Megahan and 

 Kidd In press). Sediment yield data for individual watersheds shown in table 3 

 represent material eroded from the road prism by surface erosion unless otherwise 

 noted. Surface erosion can be described as movement of individual soil particles; it 

 includes both sheet and gully erosion. 



Table 3. --Sediment yields from road erosion in the Deep Creek study area 



Measurement : Elapsed : Watershed : Watershed : Watershed : : 



period : time : 1 : 2 : 3 : Total : Average 



Days _______ Cubic feet --------- Tons/day /mi. 



of road 



11/60 - 



6/61 



232 



0.0 



0.0 



0.0 



0.0 



0, 







6/61 - 



11/61 



134 



.0 



.0 



.0 



.0 





,0 



11/61 - 



6/62 1 



238 



778. 3 



1,089.0 



14.7 



1,882.0 



109, 



,0 



6/62 - 



10/62 



120 



67.6 



62.8 



9.1 



139.5 



16, 



,0 



10/62 - 



11/62 



20 





Period of log 



ging on study 



watersheds 







11/62 - 



5/63 



195 



.0 



83.3 



68.3 



151 .6 



10, 



,7 



5/63 - 



9/63 



113 



.0 



73.0 



.0 



73.0 



7. 



,8 



9/63 - 



5/64 



251 



.0 



1.8 



9.7 



11 .5 





,6 



5/64 - 



10/64 



128 



.0 



.0 



.0 



.0 





,0 



10/64 - 



6/65 2 



252 



.0 



40 .4 





40.4 



4 



,4 



6/65 - 



9/65 



105 



.0 



9.4 





9.4 



2, 



,7 



9/65 - 



6/66 



258 



2.2 



60.4 





62.6 



6, 



. 5 



6/66 - 



9/66 



100 



.0 



.0 





.0 





,0 



9/66 - 



5/67 



250 



.0 



11.3 





11.3 



1 



,2 



5/67 - 



9/67 



120 



.2 



32.0 





32.2 



7. 



3 



Total sediment accumulation from surface erosion = 2,413.5 cubic feet 

 Total sediment accumulation from mass erosion 2 - 6,030.0 cubic fe et 



Total sediment accumulation from road erosion = 8,443.5 cubic feet 



Road construction completed during this period. 



Dam number 3 irreparably destroyed by a road fill failure (mass erosion) on 

 4/23/65. Field measurements at the failure site indicated 6,030 cubic feet 

 of material moved down the channel. 



5 



