Forty-four records of reservoir trap efficiency and the factors affecting trap efficiency are analyzed. The capacity-inflow (C/I) ratio is found to offer a much closer correlation with trap efficiency than the capacity-watershed (C/W) ratio heretofore widely used. It appears likely from the cases studied that accurate timing of venting or sluicing operations to intercept gravity underflows can treble or quadruple the amount of sediment discharged from a reservoir. Desilting basins, because of their shape and method of operation, may have trap efficiencies above 90 pct even with very low C/I ratios.
Semi-dry reservoirs with high C/I ratios, like John Martin Reservoir, may have trap efficiencies as low as 60 pct. Truly “dry” reservoirs, such as those in the Miami Conservancy District, probably have trap efficiencies in the 10 to 40 pct range, depending upon C/I ratio
[1]
G. Brune.
A comparison of the sediment loads carried by the Missouri and upper Mississippi rivers
,
1949
.
[2]
G. Brune,et al.
A consideration of factors influencing reservoir‐sedimentation in the Ohio Valley region
,
1941
.
[3]
H. Eakin,et al.
Silting of Reservoirs
,
1939
.
[4]
Allen Hazen,et al.
Closure of "Storage to be Provided in Impounding Municipal Water Supply"
,
1914
.
[5]
G. E. Harbeck.
Reservoirs in the United States
,
1948
.
[6]
Carl B. Brown,et al.
Discussion of "Sedimentation in Reservoirs"
,
1944
.