Dam could blow state's deadline

The Ragged Mountain Dam, a major component of the area’s long-term water supply plan, may not be finished until as late as early 2013, a review panel has concluded. That would be nearly two years after a state deadline mandating the dam’s repair or replacement.

The water supply plan calls for a bigger dam at the Ragged Mountain Reservoir to increase water storage from 464 million gallons to 2.19 billion. The review panel recommends that the Rivanna Water & Sewer Authority plan for the project potentially to take until late 2012 or early 2013; the state, however, has imposed a deadline of June 2011 to fix or replace the dam because of safety concerns.

Thomas L. Frederick, the RWSA’s executive director, said the plan to resolve those concerns would have been to construct the new dam.

“If there is a need for more time, just to do what’s possible, then we may have to talk to the permitting agencies,” Frederick said in an interview.

The Virginia Department of Conservation and Recreation could force the Ragged Mountain Reservoir to be drained if the deadline isn’t met, and residents could be placed on mandatory water restrictions. Rivanna had originally planned for the dam to be built by 2011 and filled by that fall.

The panel’s report, which the RWSA released Tuesday, outlined how the authority could reduce costs for a new dam without compromising safety requirements. The independent review team, comprising three engineers, was convened by the authority after the cost to replace the Ragged Mountain Dam more than doubled from its original $37 million estimate.

Area governments agreed last year that no work would be done on the dam’s construction until several studies were completed, including the one released Tuesday.

The project’s costs initially skyrocketed because an engineering firm discovered fractured bedrock where the new dam’s foundation would be built. Another estimate of the dam project pinned costs at $56.6 million.

Charlottesville Mayor Dave Norris said he personally still questioned whether a new dam is needed to fulfill the region’s long-term water needs.

“Even a revised cost estimate, a lower cost estimate, for a new dam is going to be dramatically higher [than expanding the existing dam],” he said.

In the report, the panel advised preparing for the later completion date because of the halted design work and the lingering uncertainty over geophysical and geological conditions.

Officials agreed that it made sense to convene the panel because of the swings in the estimates and the magnitude of the water plan’s total cost, which was previously estimated to be $142.8 million. But the area still needs to move ahead on the plan, said Dennis S. Rooker, a member of the Albemarle County Board of Supervisors.

Rooker said that while the area has experienced substantial rainfall and has been operating on nearly full reservoirs, “we don’t know if that situation is going to last and we need to move forward expeditiously.”

Other recommendations in the report included evaluating a different and much less expensive alternative for the left and right abutments of the proposed new dam, and considering a shallower dam foundation to reduce costs.

The panel stopped short of offering a new cost estimate for the dam project, saying it would be prudent to complete subsurface investigations for the dam’s design prior to revising the estimate. However, they also suggested that design-related work resume and that the authority proceed with choosing who would be tasked with that part of the project.

“There’s been no decision made at this point, if we’re going to restart the project with Gannett Fleming or if we’re going to take a new direction,” Frederick said. Gannett Fleming was the firm originally responsible for the project’s design, engineering and construction.

At the same time that the local boards agreed to have an independent review of the dam’s past cost estimates, officials also agreed to review the conceptual design of the pipeline that would transport water from the South Fork Rivanna Reservoir for storage at Ragged Mountain. The RWSA also authorized a dredging feasibility study for the South Fork reservoir late last month.

Of the entire water supply plan, Norris said, “We won’t know the answers until we complete these studies.”