RWSA adopts schedule for dam replacement to satisfy state regulators
By Sean Tubbs & Brian Wheeler
Wednesday, November 25, 2009
Rivanna Water and Sewer Authority
(RWSA) will receive permission from state regulators to allow for the two dams at the
Ragged Mountain Reservoir
to continue operating through the end of May 2010. On Tuesday, the RWSA Board of Directors adopted a schedule for replacement of the dams, even though a final decision on their future will not be made until next spring at the earliest.
The two dams have been operating under conditional permits from the Department of Conservation and Recreation’s (DCR) dam safety division due to their age and concerns about their structural viability in the event of a major flood. The upper dam was built around 1885 and the lower dam was built around 1908.
community water supply plan
adopted by Albemarle and Charlottesville in June 2006, the dams are to be replaced by one taller dam downstream that would raise the water pool by 45 feet. The new dam is only one component of the 50-year water supply plan.
In September 2008, the new Ragged Mountain Dam’s
preliminary cost estimates increased from an initial $37 million to a range between $56.5 million and $99 million
(in 2010 dollars). While the new estimates were not accepted by the RWSA, water officials did seek the opinion of an independent panel of dam experts and afterwards decided to hire a new engineering firm to design the dam.
In response to the escalating cost projections, Mayor
and other city councilors have raised the possibility of repairing the lower dam to address DCR’s safety concerns, or alternatively to build on top of the 1908 dam by adding just 13 feet.
In order to receive the new conditional permit, the RWSA was required to submit a new timeline for replacement or repair of the dams. RWSA officials opted to use a schedule which indicates preliminary design of the new dam will be ready by August 2010, with construction to be completed by October 2013.
said she understands the reason for the new schedule, but has reservations about how the schedule might be interpreted by opponents of the water supply plan.
“There is concern the schedule implies consent for the new dam when there’s still a lot of information out there that we have not yet obtained,” Edwards said.
At first, Edwards asked for consideration of the new schedule to be deferred until January so Council could have time to discuss the matter. RWSA Executive Director Tom Frederick pointed out that the current operating certificate for the dam expires at the end of November.
Despite her concerns, Edwards voted to approve the new schedule after said the Board’s approval was not in any way to be seen as an endorsement of the community water supply plan.
Also at Tuesday’s meeting, the RWSA Board deferred consideration of a proposal to have the same firm that is designing the new dam conduct a study on repairing or expanding the Lower Ragged Mountain Dam.
Under the terms of the proposal, Schnabel Engineering would be paid a fee of up to $188,000 to conduct what project manager Chris Webster called a ‘condition assessment’ of the structure.
Betty Mooney with the group Citizens for a Sustainable Water Plan said she thought Schnabel should not be given a contract to study the existing dam because of their existing relationship with RWSA.
“I do see this as a conflict of interest,” Mooney said. “They’re designing the new dam and I don’t feel the public can trust information coming from them.” Mooney said she was also opposed to raising the dam by any amount and said the community will not need the amount of water that the RWSA has claimed will be necessary by 2055.
Webster said his firm had an obligation to remain unbiased.
“As a professional engineering firm, it’s our duty to provide what we think is the best recommendation for the client,” Webster said. He added he is not prepared to provide even a preliminary cost estimate for adding on to the dam because his engineers do not yet have enough data.
“Due to all of the background information that we currently have, the dam is in somewhat poor condition and we feel a fairly rigorous study would be necessary to determine whether or not it could be used beyond its current life,” Webster said.
Dan Johnson, vice president of GEI Consultants in Boulder, was a member of the expert panel assembled by RWSA earlier this year to review engineering data and a 1913 safety report for the lower dam. He confirmed in an August interview that the independent panel did express what Frederick has described as “significant concerns” about any construction taking place on the 1908 dam.
“Work could be done, but you would have to lower the reservoir [water level],” said Johnson. “There was discussion about raising the existing dam… but there is no great cost benefit and you end up with an old dam integrated with a new dam. With an entirely new dam downstream, you can keep operating the reservoir, and that is very valuable.”
A vote on whether to accept Schnabel’s proposal was deferred until the RWSA Board’s meeting in January. City Manager Gary O’Connell said Council will take up the proposal and other water supply issues at its first meeting in January.