WSP06343

• File Number: 8220.124.A
• Description: Pine River
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 1/1/1951
• Author: USDOI Bureau of Recl
• Title: Pine River Project Extension Colorado and New Mexico
• Water Supply Pro - Doc Type: Report/Study

NATIONAL PARK SERVICE BEPORT

General Description of the Area

Location

The Vallecito Reservoir is located on the Los Pinos or Pine River,
at the confluence with Vallecito Creek. It is in east central La Plata
County, southwest Colorado. Sources of the Pine River lie near the
Continental Divide shortly to the northeast, opposite sources of the Rio
Grande which drains into the Gulf of Mexico. The dam is just inside the
boundaries of the San Juan National Forest, and the reservoir is approxi-
mately 15 miles north of Bayfield on U. S. Highway 160, most important
east - west highway across this part of the state. By this route the
reservoir is about 33 miles northeast of Durango, most important community
in the vicinity. A somewhat shorter, if more seasonal, approach is
afforded via the Florida Valley route, estimated (from road maps) to be
about 25 miles. Under favorable conditions, access from the north via
U. S. 550 would be from this direction rather than from Bayfield.

Purpose of Reservoir

The Vallecito Reservoir has been in operation since 1941 for the
purpose of storing water for the irrigation of the present 33,160' acres
of the Pine River Project. However, the actual capacity of the reservoir
is sufficient to permit the extension of the project now under considera-
tion, to include irrigation of an additional 15,150 acres. The effect of
the project extension on the Vallecito Reservoir itself would involve
changes in reservoir operation, and not additions to the dam or increases
in reservoir storage capacities.

The top of the earth-filled dam is given as elevation 7,673 with the
maximum water surface established at el. 7,665 with a capacity of 129,700
acre~feet, and a surface area of 2,723 acres. Stream bed elevation at
the dam is indicated at 7,551 feet, MSL.

Table I gives the actual'reservoir operation for the present area of
33,160 acres of the Pine River Project, indicating the active capacity in
the reservoir at the end of the month, from April 1941 through January 1948.

Table II is especially significant in connection with recreational
values that have resulted from the creation of the Vallecito Reservoir,
giving as it does, the maximum and minimum active storage pools which
occurred each month during the same period of operation (except 1948
operation months, November 1947-January 1948). It is noteworthy that
maximum pools occur in June or July, which is consistent with the import-
ance of melting snows in the high mountain watershed as a source of water.
It is equally noteworthy that minimum pools tend to occur during autumn
and winter months, since the major use season at elevation 7,600 in this
part of Colorado i6 generally accepted as May - October inclusive.

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