WSP11510

• File Number: 8143.600.30B
• Description: John Martin Reservoir - Other Studies
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 11/1/1973
• Title: Report on Sedimentation - John Martin Reservoir - Arkansas River Basin Colorado -- Resurvey of March 1972
• Water Supply Pro - Doc Type: Report/Study

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acre-feet while during the period August 1968 to March 1972 (3.7 years)

there was a storage gain of 2,658 acre-feet. Detailed data are presented

in table 3, which is a copy of the Reservoir Sediment Data Summary,

ENG Fonn 1787.

33.

The suspended sediment retention from September 1966 to March
"-
computed to be 4,076 acre-feet or less than half the storage

1972 was

reduction shown by the resurvey of the reservoir. In general retention

from suspended sediment would account for about 85 percent of the storage

reduction. Some of the difference can be attributed to the consistent use

of the assumed dry weight of sediment of 75.7 powlds per cubic foot for the

entire period of observation. The effects of using the Constant Factor

Method for volume computations and the correction brought about by the 1968

topographic survey also effected the computations. Results of the topo-

graphic survey of 1968 were used to determine the capacity for August 1968

and there was a computed gain in storage space from August 1968 to March 1972

of 2,658 acre-feet. Some of this can be seen from the partial range line

plotting on plate 23 which shows a well defined channel established after

the 1966 survey. There were 1,201 acre-feet of sediment removed by this

channel between range 13 and the dam. Table 11 is a comparison of channel

sections in the reservoir between the dam and range 13. In addition there

was noticeable consolidation from Water Year 1968 through March 1972. This

accounts for a storage gain of 1,338 acre-feet. Thus the total storage

gain from these two sources was 2,539 acre-feet. Table 12 lists consolida-

tion of the sediment.beds.

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