WSP07461

• File Number: 8143.600.30
• Description: John Martin Reservoir - Other Studies
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 9/1/1982
• Author: Dept of Army
• Title: John Martin Dam and Reservoir - Small Hydropower Addition Reconnaissance Report
• Water Supply Pro - Doc Type: Report/Study

~
(.;-.
o

~)

PRELIMINARY

SUBJECT TO REVIS!ON

cycle is periodically interrupted by storage of flood runoff. The Flood

Control Act of 1965 (Public Lay 89-298. 89th Congress. S2300) authorized the

Corps of Engineers to allocate 10.000 acre-feet of storage capacity for

recreation and fish and yildlife purposes. It yas not until the spring of

1980 that local interests yere able to provide yater for the recreation pool

yhen approximately 10.000 acre-feet of transmountain water yaS delivered to

John Martin. This water has not been replenished and has been subjected to a

substantial evaporative loss. As of 1 July 1982. the permanent pool account

held 4469 acre-feet. The Colorado Division of Wildlife has played an active

role in attempting to establish a permanent pool at John Martin. however.

their attempts to date have been delayed by law suits and no agreements for

permanent storage at John Martin have resulted. A valuable sport fishery has

been established in the reservoir by stocking of warm-water game fish. The

future existence of this recreational resource is dependent on the existence

of a permanent pool. It remains to be seen what success the State of Colorado

or other local agencies will have .in purchasing the water required to maintain

a permanent pool at John Martin Reservoir.

D.

RpRPrvnir Inflows.

J'

1. Another hydrologic matter of interest is the steady decline of

mean annual infloy to John Martin that has occurred during the forty years of

operation history of the project. A graph of accumulated mean annual inflow

to John Martin Reservoir is shown on Plate 1. The high values during the

early years of operation resulted from the flood that occurred in April 1942.

In the last tyenty years of operation the mean annual infloy has decreased

about 21 percent. The last ten years has seen a decrease in the mean infloy

of about 12 percent. An explanation for this phenomenon is undoubtedly of a

complex nature. The reasons could include an expanded total acreage of

irrigated land. additiona roundwaters. additional ect

..
diversions. yinter yater storage in Pueblo Reservoir. Or a natural dry cycle.

The impact of this trend of decreasing yater supplv should be investigated in

future. more detailed hydropower studies.

~~\V
. /./-

L

2. The flow in the Arkansas River is also affected by transmountain

diversions from the Colorado River Basin via the Fryingpan - Arkansas Project.

5