A malfunction at the Animas-La Plata Project has halted pumping and could push back the date the reservoir is full by six months, Bureau of Reclamation officials said Tuesday.
Problems with the crest gates, which are part of an intake structure that allows water to flow into a forebay or fish screen area before it is pumped up the hill, caused the system to be shut down since early last week.
"It's a minor issue, but it keeps us from pumping any water," said Barry Longwell, the bureau's deputy construction engineer for the project.
The gates are air operated and one of the lines has become pinched. The result is that the gates can be moved only to the all-the-way-down or all-the-way-up positions.
Though the problem is expected to be remedied within a couple of days, the malfunction occurs as the river is flowing high from the spring snowmelt, which came unusually early this year.
Tyler Artichoker, first-fill project manager, said officials had optimistically projected Lake Nighthorse could be full by July 2010, but that depended on being able to take advantage of the seasonal high flow.
"Because we're missing a lot of that right now, working out some of the bugs in our system, and we have not ramped up to full capacity pumping yet, it does give us a lot of concern that we're going to push that at least into August, September of next year," he said.
Artichoker and Longwell discussed the malfunction as part of an update on the project made to La Plata County commissioners at their request during their regular meeting Tuesday.
Because pumping may be halted at times during fall's low-flow months, this could further delay filling the lake.
"It does have a potential to increase that duration by a good six months or more," Artichoker said. "We want to get the plant operational while we still have significant flows in the river."
Though the malfunction represented a major, albeit temporary, roadblock, Artichoker said it was to be expected with a project this size. There may still be other kinks to work out.
Additional hindrances could push the fill date out two years or more, he said.
"My crystal ball is no better than anyone else's," he said.
The massive water project has been 40 years in the making and eventually will provide water to three Native American tribes and other entities in Colorado and New Mexico. It will be slightly smaller then Vallecito Lake, but, because it will be deeper, will hold about the same amount of water.