By Sean Tubbs

Charlottesville Tomorrow

Friday, January 21, 2011

The

Albemarle County Service Authority

is welcoming

this week’s vote by the Charlottesville City Council

in favor of raising the pool height of the Ragged Mountain Reservoir by 30 feet, rather than the 13 feet the council had previously supported.

“The city has made a big step forward,” said

Jim Colbaugh

, who represents the Scottsville district on the ACSA Board of Directors.

“I applaud the City Council for making this move,” echoed

Liz Palmer

, the newly elected vice chair of the ACSA board.


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Chris Webster of Schnabel Engineering updates the ACSA on the progress of the earthen dam design


However, the council’s resolution did not specify whether the bigger pool would be accomplished through building on top of the existing

Lower Ragged Mountain Dam

, or through an all-new earthen dam built downstream.

The

ACSA agreed last fall

to pay the entire cost for

Schnabel Engineering

to produce a final design of the earthen dam in order to keep the project on schedule. On Thursday, the ACSA authorized Schnabel to complete the work.

“It will get us through all the issues we need to do from a design standpoint, beginning to look at all the permitting and all the information that needs to be done for that,” said the ACSA’s executive director,

Gary O’Connell

.

The

Rivanna Water & Sewer Authority

has a May 31 deadline to demonstrate to the Virginia Soil and Water Conservation Board that progress has been made toward addressing the existing dam safety issues at Ragged Mountain.

“We’re still on track for the completion of documents in mid-April which will meet the requirements,” said Chris Webster, the project manager for Schnabel.

However, Webster said his firm has not begun work on proposed modification to the Department of Environmental Quality and Army Corps of Engineers permits issued in 2008 because several questions remain, including which design to use for the dam.

Last fall, the

City Council

hired the firm

Black & Veatch

to produce a feasibility study for repairing and expanding the existing

Lower Ragged Mountain Dam

, which was originally built in 1908.

At their meeting Feb. 7, councilors will consider whether to retain Black & Veatch to further advance that design in support of the council’s action earlier this week.

Another issue from the ACSA’s perspective is whether either dam will be built to its full height, or whether it will be built in two phases.

Since Tuesday night’s council meeting, Webster said his team has been revising the cost estimates for building the earthen dam in two phases at the council’s request.

“Considering the scenario of a 30-foot raise, the initial phase, we’re looking at a cost of $17.548 million,” Webster said. “[That’s] 99 percent of the cost of building a full-height dam.”

Webster said the second phase, required to raise the pool to the full 42 feet necessary to meet the goals of the 2006 water plan, would cost an additional $1.69 million.

He added that one issue with a second phase was the possibility of needing to lower the reservoir at that time in order to obtain fill material from the reservoir’s floor and bank to use for the dam.






Jim Colbaugh


Colbaugh asked if fill materials for the second phase could be stockpiled during the construction of the first phase. Webster said it could but the fill would have to be properly stored to protect it from the elements.

“Why not stockpile it on top of the dam?” Chairman

Clarence Roberts

quipped.

Colbaugh said he was concerned that action by the city to design a concrete dam would cause further delay, because that work would not be finished until later this year, too late to satisfy the state’s deadline. He suggested meeting the city halfway.

“I would suggest that we go with a 30-foot pool and agree that we will have no more than a 30-foot pool until certain triggers are set.”

Roberts said he didn’t have enough information to make any decisions at this point.

Palmer said she wanted input from Albemarle’s

Board of Supervisors

before she could take any action.

“I don’t think we’re going to lose any time since we don’t even know what dam we’re talking about and we can’t apply for the permit until we do know,” Palmer said. However, she said there are still a lot of unknowns, including how to develop a trigger to determine when phase two would be constructed.

ACSA board member

Dave Thomas

said he could support a compromise, but held out hope that the city would see the benefits of building all at once, even if the reservoir wasn’t filled to its full height until it was necessary.

“I have no problem with a 30-foot additional dam height, conservation triggers and all the measures designed to ensure adequate instream flow,” Thomas said. “I simply don’t see a reason to go only to 30 feet if everybody agrees that eventually we’re going to have to go to 42 [feet].”


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