RWSA approves 30′ reservoir redesign for Ragged Mountain


After recent votes by the Charlottesville City Council and Albemarle Board of Supervisors, the Rivanna Water and Sewer Authority (RWSA) authorized $28,500 in engineering fees and an extended design deadline for a new earthen dam, to replace the existing Lower Ragged Mountain structure.

The deadline for a final design, according to memo from RWSA Executive Director Tom Frederick, will "now be due from Schnabel [Engineering] on April 29, the last working day before the deadline before completing final design requested by the Virginia Soil & Water Conservation Board." In November, the Soil & Water Conservation Board extended the temporary operating permits for the Ragged Mountain dam, which gave the RWSA an additional six months to address safety concerns regarding the dam’s insufficient spillway. The contract for constructing a new dam could be put out to bid by May, with construction beginning before the end of the year.

While city and county officials have agreed on a 30′ initial reservoir raise, however, the height of the dam itself remains undecided. In January, Schnabel Engineering’s Chris Webster said that a 30′ earthen dam would carry 99 percent of the cost of a 42′ build. A phased build-up to 42′, however, would cost 108 percent the price of a one-time build to a full 42′.

This week, the Albemarle County Service Authority (ACSA) also approved the 30′ reservoir raise. ACSA Board Member Liz Palmer maintains that a dam to support a 42′ reservoir pool "would certainly have been the wisest use of rate payer’s money."

A 42′ reservoir, says Palmer, "would cushion us if growth turns out to be what is projected and against what climate change may bring in the form of longer and more intense dry periods." 

"Any extra water in storage is water we do not have to  withdraw from the South Fork Rivanna  river and the Moormans when flows are at their lowest in the summer months," says Palmer. "This means better stream flows and a healthier watershed.

At present, city and county officials still need to determine a cost allocation for the water supply plan—the dam, as well as a pipeline from the South Fork reservoir to Ragged Mountain, and expanded capacities for the Observatory and South Fork water treatment plants. Along with costs, Frederick says both city and county officials continue to discuss triggers that would raise a 30′ dam to 42′ at a later date.

"I’m not aware of a deadline for this decision," says Frederick, "but believe it is in the interests of the citizens of this community that it be reached soon.