Reservoir report finally completed, but now what?

When a task force finalized its blueprint for the future of the South Fork Rivanna Reservoir this week, it punted controversial decisions about dredging back to local officials.

The 25-page report details benefits of dredging the reservoir to remove sediment that has built up for decades. However, the report falls short of recommending dredging, suggesting instead how officials can decide for themselves whether “selective dredging” should be in Charlottesville and Albemarle County’s playbook.

So what’s it mean?

“I think it definitely moves them closer to doing a dredging study,” said Dennis S. Rooker, who represented the Albemarle County Board of Supervisors on the task force.

The task force was charged with determining the benefits of dredging, yet was also instructed not to reassess the long-term water supply plan approved in 2006, which would expand the storage capacity for drinking water at the Ragged Mountain Reservoir.

The task force’s charter meant that certain conclusions were all but off the table before discussions even began, some said.

“If you start with a given that the water supply plan is in place … it becomes difficult to justify the recommendation of complete dredging of the reservoir, because that additional storage is not needed in the 50-year water-supply plan,” Rooker said.

Wren Olivier, a task force member representing the Sierra Club, criticized what she portrayed as an unfair limitation. She said that the charge given to the task force prevented members from looking at the very question that the community wanted answered: “whether restorative dredging of the reservoir is, in fact, a viable option for our water supply.”

“I think the issue is: We wanted to have a study of restorative dredging to see what it would cost,” Olivier said. And from there, she said, officials could determine the best course of action, using the best possible information.

Down to specifics

Instead, the task force report outlines benefits of removing sediment only in vital areas of the South Fork reservoir.

Increasing water storage was identified as a possible short-term benefit of dredging, because it would reduce the risk of a water shortage in case of a drought prior to the year 2021. In 2021, the construction of a new dam at Ragged Mountain Dam and a pipeline that would pump water from the dam to the South Fork reservoir is expected to be complete.

The cost of the water supply plan was initially estimated at $142.8 million. However, an engineering firm more than doubled the cost estimate of building a new dam at Ragged Mountain after fractured bedrock was found at the site where the dam’s base would be built. Critics estimate that the final costs of the water supply plan could exceed $200 million.

If officials determine that there is a serious risk of a near-term water shortage, the report recommends, they should consider “a modest level of dredging.”

The report raised questions about whether failing to dredge would mean that dredging would become impossible in the future because of wetlands formation. If no maintenance is performed, an estimated 30 acres of wetlands are likely to form in the reservoir, the report says. The task force recommends the Rivanna Water & Sewer Authority further investigate the matter.

“If and when the community decision-makers” conclude there is a compelling reason to dredge, officials should determine whether the benefits outweigh the “potential costs,” the report says. To determine those costs, the report suggests identifying the areas of highest priority for dredging and collecting data about whether obstacles, such as tree stumps in the reservoir, would increase the costs.

The report also suggested determining the water depths and sediment compositions, as well as the effect dredging would have on nearby residents, water quality and aquatic life. The report notes that allowing contractors to dredge at the rate at which they can sell the sediment — assuming the material is valuable — would likely be the least expensive way to dredge.

Though the South Fork is often called the best reservoir in the county for fishing, the report says that public access points are limited. It’s debatable whether the formation of shrub and tree-filled islands have improved or damaged the reservoir’s beauty.

The report recommends that the Rivanna Water & Sewer Authority monitor the growth of hydrilla, an invasive aquatic plant growing in the South Fork reservoir, because the presence of too much hydrilla could hurt water quality and fish habitats.

Statement denied

Three task force members sought unsuccessfully to have an attachment from the Piedmont Group of the Sierra Club included in the final report. The statement recommended studying the cost and feasibility of dredging the reservoir.

Though the motion to include the statement was voted down, Olivier was asked to read the statement so that it could be included in the meeting minutes.

Olivier maintains that dredging should be considered as a possible centerpiece of an alternative water supply plan.

“If we made some effort to promote conservation along with also looking at control of our growth … that could fit together.”

Officials say that dredging alone would not create enough water storage capacity to meet the community’s long-term needs.

Dede Smith of Citizens for a Sustainable Water Supply Plan and Charlottesville City Councilor Holly Edwards also voted to have the attachment included in the final report.

Edwards said that a dredging study should be done, for the sake of transparency, to provide the community all the facts and to allow officials to have “a menu of options.”

Smith and Olivier were the only members of the 13-person task force who voted against the final report, which will be given to Charlottesville and Albemarle officials. It is unclear when the local leaders will take up the matter.