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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in April 1942. At that time the dam was not complete but the flow was

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restricted as it passed through low monoliths in the dam. A large pool

was formed above the dam and more than 50 percent of the sediment inflow

was deposited. Details of the operation prior to the period covered in

this report are explained in the 1953 and 1960 reports. From the spring

of 1957 to the fall of 1959, the reservoir was at a relatively high stage.

The next S-1/2 years were dry and there was only a small amount of winter

storage and long periods when the reservoir was empty during the summers.

The June 1965 flood filled the reservoir to about elevation 3,853 and

operations were above elevation 3,850 until April 1966. After -that storage

declined until the reservoir was empty in April 1968. From then until

March 1972 there have been small amounts of winter storage and long empty

periods during the summer.

14. Inflow and outflow. The monthly inflow and outflow in acre-feet

for John ~Iartin Reservoir from October 1942 through March 1972 are tabulated

in table 2. These data were taken from the daily operation reports. The

total monthly flows past the two inflow gaging stations, Arkansas and

purgatoire Rivers at Las Animas, for the period 1943 through March 1972

are presented in table 6. The reservoir inflow obtained from the daily

operation reports and the reservoir inflow obtained from the flow passing

the inflow stations do not agree for the same periods for several reasons.

There is a small inflow below the gages from springs, arroyos, and one

ephemeral tributary. In addition, the ungaged area frequently contributes

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