The Chair of the South Fork Reservoir Stewardship Task Force gave a preliminary report on the group’s progress to the
Planning and Coordination Council
(PACC) at their meeting on November 20, 2008.. The PACC consists of representatives from the City Council, Board of Supervisors and University of Virginia and meets on a quarterly basis to address issues of common interest to the three groups. The report given by Supervisor
(Samuel Miller) represented her views and not those of the Task Force.
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Thomas said it is likely that some form of dredging will be recommended for the South Fork Reservoir at some point because sedimentation has formed islands behind fallen trees and along the edges of the reservoir and is decreasing its water storage capacity. According to Thomas’ report, dredging would help to meet the projected fifty year water supply demand but it would not fully meet its requirements. Dredging South Fork is not a requirement of the approved water supply plan. [
Editor’s note: See correction in comment below
A potential issue raised by Thomas was that the bottom of the reservoir could possibly contain stumps and debris that would prevent effective dredging. Additionally, one acre of hardened land is necessary for the dredge to enter the water and refuel. Studies would need to be done on the impact of that land use on local soil erosion. It has been suggested that the dredges could enter the reservoir by way of Ivy Creek, the Task Force is currently examining if the bridge at Ivy Creek is too low to make that a feasible entry point.
According to Thomas, “recreation is probably the strongest reason to dredge.” The UVA Rowing Team, whose former members have won several Olympic medals, uses the reservoir for practice. Hydrilla, an invasive plant species has been growing in their typical practice routes due to the increased sedimentation. The rowers only need a 4ft deep channel in order to practice but to stifle the hydrilla the channel needs to be at least 10 feet deep.
Thomas reported that the differences in cost predicted for dredging do not come from the cost of removing the sediment itself, but rather the cost of “what you do with the mud” after it has been removed from the reservoir.
The Task Force was briefed by a representative from the Charlottesville Airport
who said that the airport may have found enough soil on site to meet their need and therefore they would not be interested in purchasing the dredged sediment. Furthermore, according to FAA standards, the airport cannot use any soil that may contain fish or other wildlife that would attract birds to the runway.
Thomas said, “it’s a symbolic concern,” that people are so worried about their water supply, and that people do not want to witness the “death” of the reservoir. However, she pointed out, “it’s not unusual what we’re seeing,” many other places have experienced similar problems, but “we could be leaders” in finding creative solutions to deal with the sedimentation.
who sits on the PACC, expressed surprise that there are no better records of whether or not stumps had been removed before the reservoir was filled. Additionally, he asked if dredging would affect water quality. Thomas responded that while the plans for the reservoir set forth that the stumps were to be removed, eyewitnesses have come forward saying that it may not have happened. As far as water quality goes, Thomas said that screens can be installed when dredging begins to ensure the water coming out of the reservoir is as free from debris as possible. She did say that there is more concern that the pumps used to transport the sediment away from the reservoir are gasoline powered and therefore a plan would have to be made to ensure that they did not contaminate the drinking water in any way.
The task force will next meet on December 8, 2008 to continue its deliberations.