Navajo Dam is on the San Juan River in northeastern New Mexico about 34 miles east of Farmington. The dam is a rolled earthfill embankment with a structural height of 402 feet and a crest length of 3,648 feet. The dam contains 26,840,863 cubic yards of materials. The top width of the dam is 30 feet, and the maximum base width is 2,566 feet.
The spillway, on the right abutment, consists of an approach channel, concrete crest structure without gates, spillway bridge, concrete chute and stilling basin, and outlet channel. The width of the spillway ranges from 138 feet in the chute section to 195 feet in the stilling basin. The design capacity at maximum water surface elevation is 34,000 cubic feet per second.
Releases of water for downstream requirements are made through the outlet works, consisting of a concrete tower intake structure, an 18.75-foot-diameter concrete-lined tunnel, and valve house. Control is by one 6- by 13-foot fixed-wheel gate, two 72-inch ring-follower gates, and two 72-inch hollow-jet valves. The outlet works tunnel, located in the right abutment, is 1,603 feet long. Discharge capacity is 4,200 cubic feet per second at an elevation of 6,101.5 ft.
An auxiliary outlet works consisting of a concrete intake structure and a concrete-lined tunnel with gate chamber for two 4-foot-square gates also is located in the right abutment. Discharge is into the spillway stilling basin.
Navajo Reservoir extends 35 miles up the San Juan River, 13 miles up the Pine River, and 4 miles up the Piedra River in southern Colorado. When filled, the reservoir occupies 15,610 acres, with a total capacity of 1, 708,600 acre-feet and an active capacity of 1,036,100 acre-feet.