One year out

Elkhead Reservoir construction on track for 2007 opening


By this time next year, outdoor enthusiasts likely will be enjoying Elkhead Reservoir's resources again.

The project is on schedule to open next summer, officials said during a media tour Thursday of the $27 million expansion project.

The reservoir closed in December 2004.

The reasons for expanding Elkhead Reservoir are as varied as the uses for an acre-foot of water, said Ray Tenney, engineer for the Colorado River Water Conservation District.

They include saving endangered fish, providing recreational opportunities and storing water for future use downstream.

The project that was 14 years in the planning is now in its last year of construction. The reservoir, which straddles the Moffat County-Routt County line, will almost double in size when it fills to capacity, possibly by next summer.

The original dam, built in 1974, will rise from a height of 80 feet to 105 feet. Water storage will increase by 11,750 acre-feet. An acre-foot is about 326,000 gallons of water, enough to supply two average households for a year.

"You can see the screens on the intake tower," Tenney said. "Those are to keep non-native fish in the reservoir and out of the river."

The tall concrete tower with various inlets is one of the first things visitors notice at the construction site. It connects to a tunnel that is 6 feet in diameter and 510 feet long that can drain the reservoir to levels below what was previously possible in case of emergencies or extreme drought.

Also nearing completion is the new spillway, a sloping concrete ramp that can handle 28,000 cubic feet per second of water in a high runoff situation.

Unlike the old structure, the new spillway is away from the dam to reduce any chance of erosion to the dam by water cascading down the spillway.

Workers drilled hundreds of holes in the dam and filled them with grout to prevent any water from seeping through the dam.

The spillway has numerous blocks of concrete at the bottom of the ramp to dissipate the energy of the moving water before it enters Elkhead River below the dam.

Colorado State Parks and the city of Craig plan to construct campsites near the water, as well as two boat ramps. The present boat ramp will be enlarged, and a new ramp is being considered farther north toward the inlet for anglers fishing in the no-wake zone.

Fish such as the Colorado pikeminnow, bonytail, razorback sucker and the humpback chub will benefit most from the expansion, Tenney said.

In a project funded by the Upper Colorado Endangered Fish Recovery Program through the federal Bureau of Reclamation, 5,000 acre-feet of water contained in the new reservoir will be allocated to protect endangered fish.

"Low water levels in the river favors the non-native fish," Tenney said. "That 5,000 acre-feet for the fish recovery program will keep river levels up to benefit the native species."

By late November, the construction crews should be wrapping up the project, and the dam road is scheduled to reopen, weather permitting.

Spring runoff in 2007 should fill the reservoir once again, and construction on campgrounds and boat ramps can be completed.

Water being let out of the reservoir will be adjusted by city of Craig Water Department workers. They will release water as required by leases downstream, including those of the Craig Station power plant and the fish recovery program.

The city of Craig will gain access to 3,300 acre-feet of its leased water because the tower will have lower intakes than the structure it replaced.

City of Craig Public Works Director Bill Earley said that 3,300 acre-feet will fill the city's water needs until the population reaches nearly 30,000, many years from now.

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