WSP10000

• File Number: 8200.750
• Description: San Juan River General
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 4/1/1961
• Title: Water Supply - San Juan River Basin - Upper Colorado River Commission - April 1961
• Water Supply Pro - Doc Type: Report/Study

001805

.

LITTLE NAVAJO RIVER

.

The Little Navajo direct diversion dam is located on the

Little Navajo River about 3.0 miles upstream from the gl!ge at Chromo,

Colorado, and about 0.5 miles upstream from the diversion conduit

crossing. The Little Navajo River at Chromo gage was discontinued

after September I 1952 and a direct correlation of annual runoff of the

Little Navajo River at Chromo and the Navajo River at Edith, Colorado,

was substituted after September 1952. The average monthly runoff and

Hs pEir.::ent of the annual were calculated for the period of January 1942

to September 1952 and then applied to the annual figures derived from

the correlation

The uncontrolled drainage area above the diversion dam site is

14.2 square miles and at the gage is 21. 9 square miles. The runoff at

the diversion dam site, located above the gage, was .considered as

being the same as the ru:aoff at the gage I because the depletions in the

intervening reach are minor and are offset by the tributary inflow. Water-

Supply Paper 1313 lists irrigation of about 600 acres above the gage and

a diversion above the gage for 50 acres irrigated below the station.

The maximum capacity of the diversion canal from the dam to the

conduit is 100 cfs and the diversion conduit capacity from the Little

Navajo River to the Navajo River is 550 ds. Spills were calculated by

adding the maximum capacity of the diversion canal and the required by-

pass and spilling all daily flows in excess of this figure as follows:
-6-

.

'"