LA Reservoir may reopen in 2012

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Green light for rebuilding of dam expected this month

By Kirsten Laskey

Evidence that the Los Alamos Reservoir has been dormant for quite some time is apparent beginning with the barred entrance gate.


The snow-covered road leading to the reservoir is uneven, making vehicles duck and weave around deep ruts and icy patches. Animal footprints in the snow far outnumber any signs of  humans treading in the area.

The reservoir basin is choked with brush. The remains of a nearby hiking trail are crumbling.

At first glance the dam and reservoir appear neglected, even abandoned – but a closer inspection reveals a far different picture.

During the past five years Los Alamos County has been working to obtain permits from the New Mexico State Engineer’s Office and the U.S. Forest Service – and the effort is paying off.

The preliminary schedule to rebuild the dam calls for an issuance of a Notice to Proceed on Feb. 15. Tim Glasco, Department of Public Utilities deputy manager, said this will be delayed a couple of weeks while everything is finalized with the Corps of Engineers.

The construction contract has been awarded to Kiewit New Mexico Company. Glasco said the company has done work in Los Alamos in the past and was the low bidder on this project, which has a construction price tag of $2,716,000.

Construction is expected to take six months and Glasco said although work will be complete; the reservoir will likely not be filled until spring or early summer 2012.

“I think what we present to (the public) when it is over will not only be safe but attractive,” he said. “If everything works out we should have a nice lake on county property.”

The construction project includes erosion protection work, general site work and demolishing existing features.

The Department of Energy (DOE) still owned the dam following the Cerro Grande Fire in May 2000. The watershed was severely damaged and floodwaters occurred when it rained, Glasco said. DOE was concerned about Los Alamos National Laboratory’s Technical Areas 41 and 42 and to protect the dam, placed a concrete coating around it.

Demolition work involves removing that concrete coating. Additional work includes excavation, grading and soil nail installation to stabilize the dam.

Glasco said the work is necessary because the dam’s slopes are not stable given today’s standards. The dam also requires a large emergency spillway with reinforced concrete sidewalls to define the spillway chute.

Glasco said the county took over the dam through a lease in 1998 and received ownership in 2001. In 1995 or 1996, the county asked the Office of the State Engineer Dam Safety Bureau to conduct a courtesy inspection, he said. At the time, the dam was under federal ownership and not regulated by the state.
The dam safety inspector declared the structure in relatively good shape and deemed it a low-hazard structure, Glasco said.

Then the Cerro Grande Fire hit and the upper watershed was severely burned.

As a result, the county could not do anything because the post-fire flooding brought in a large amount of sediment, Glasco said.  

He added the reservoir was dredged completely on one occasion and then partially several more times.

“The watershed has now been completely hydrologically healed and there have not been any floods or appreciable sediment accumulation in the past four years,” Glasco said.  

In 2005, the county hired an engineering firm, URS, to design repairs on the dam. But also that same year, the New Mexico State Engineer adopted new dam safety regulations.

“The amount of work required just mushroomed because of those requirements,” he said.
Glasco explained that flooding from a catastrophic failure could be dangerous to the public because the Los Alamos County Ice Rink is located down the canyon from the dam.

“Our project just grew significantly because the dam now became a ‘high-hazard’ structure,” he said.
Also, the Office of the State of Engineer adopted new regulations and was consequently swamped with work from other dam owners seeking compliance.

The county went through four rounds of submittals of preliminary modeling and design work before securing the necessary state approvals. The State Engineer permit was received Oct. 7, 2010 and the U.S. Forest Service permit was awarded Dec. 23, 2010.

Glasco said the Forest Service still owns the property surrounding the dam. The county owns the dam and there is an effort to purchase the Forest Service land.  

The reservoir is of interest to the community. People approach him in the grocery store wondering when the reservoir will open, he said.

“It was just a popular place to go,” he said. “I took my oldest kid up there to play and it was a beautiful place. It’s a nice place to go.”

According to a 1966 article in the Los Alamos Historical Society’s archives, the Ranch School began construction of the reservoir in 1942. Pipeline laid in 1921 was extended to the reservoir.

In 2008, the Los Alamos Monitor reported that the school had plans to build a larger dam but it wasn’t completed. The Army then took over and the project was completed in 1943.