Overview

Morrow Point Dam, 12 miles downstream from Blue Mesa Dam, is Reclamation`s first thin-arch, double-curvature dam. It is 468 feet high, 52 feet thick at the base, and 12 feet thick at the crest. The dam has a crest length of 720 feet and a volume of 360,000 cubic yards of concrete.

The spillway consists of four orifice-type openings in the top central part of the dam, providing a free-fall discharge higher than 350 feet to the concrete stilling basin at the toe of the dam. Each of the four spillway openings is controlled by a 15- by 16.83-foot fixed-wheel gate. Maximum capacity of the spillway is 41,000 cubic feet per second.

The outlet works consists of one stainless-steel lined 4-foot-square conduit through the dam. Control is by two 3.5-square-foot slide gates. Discharge capacity of the outlet works is 1,500 cubic feet per second.

Reservoir capacity behind Morrow Point Dam is 117,190 acre-feet at maximum water surface. The active capacity is 42,120 acre-feet. Surface area for Morrow Point Reservoir is 817 acres at an elevation of 7,160.0 ft.

The powerplant chamber is tunneled into the canyon wall in the left abutment about 400 feet below the ground surface. The powerplant chamber is 231 feet long and 57 feet wide with a height ranging from 65 to 134 feet. There are two 60,000-kilowatt generators driven by two 83,000-horsepower turbines. The power penstocks consist of 13.5-foot-diameter steel liners in 18-foot-diameter tunnels.

Geology

The dam is located in the Black Canyon of the Gunnison River, a 2,460-foot-deep gorge carved into folded precambrian metamorphic and igneous rock. The foundation is entirely quartzite and mica schist that are cut by granite pegmatite dikes, shears, and joints. The Cimarron fault is approximately 1 km from the dam.

General

Dimensions

Hydraulics & Hydrology