Reservoir Task Force discusses recommendations and water supply plan
The South Fork Reservoir Stewardship Task Force is winding down its work, and the group spent its most recent meeting preparing to make its final recommendations. On November 18, 2008, Task Force Chair
took the group through a presentation outlining some of the information that the group had been presented over the course of the fall.
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Tom Jones, who represents landowners near the South Fork Rivanna Reservoir, said he wanted to make sure that the task force’s report was clear and questioned whether the chairs of the four boards needed to see so many slides of information. Throughout the course of the meeting, Dede Smith of Citizens for a Sustainable Water Plan questioned some of the facts that Thomas displayed during her presentation.
Mark Fletcher, representing the University of Virginia, suggested that any report be written to have a long shelf-life so that future decision-makers can benefit from the information gathered by the task force. Ridge Schuyler of the Nature Conservancy said if task force members dispute a particular piece of information, the task force should try to verify the fact before throwing it out.
Thomas reminded the task force that the presentation was meant as a discussion piece, and was not meant to be the final presentation.
One new piece of information related to the frequency the proposed pipeline from South Fork Rivanna Reservoir to Ragged Mountain Reservoir would be used to transfer water. Ridge Schuyler had asked an contractor with the firm Hydrologics to model possible scenarios under which the latter reservoir would need to be filled.
“On average, that pipeline would operate fewer than 20 days a year because the [reservoir] is there for use during times of drought,” Schuyler said. However, Schuyler said the pipeline would need to be operated more frequently following droughts in order to refill Ragged Mountain. He reminded the task force that the purpose of expanding Ragged Mountain is to build a bigger storage for use during droughts.
He said that when the task force
visited the South Fork Rivanna Reservoir in August
, they saw evidence of how the South Fork can be quickly drawn down because siltation has reduced its storage capacity. Under the adopted water supply plan, Ragged Mountain’s full storage capacity would be tapped during droughts.
Mark Fletcher asked Schuyler if that meant the South Fork reservoir would continue to play a role in the water supply plan. Schuyler said it absolutely would, and that the South Fork reservoir would be the primary water supply “90% of the time.”
“The South Fork is the bigger drainage area and so it makes sense most of the time to take advantage of all that water and use that to supply the City with water,” Schuyler said. “But when that flow subsides and you have to rely on storage, the storage facility is over at Ragged Mountain because it doesn’t have any sediment and it’s a big enough bowl to hold enough water to meet our needs.”
Wren Olivier, representing the Sierra Club, said if the South Fork reservoir were dredged, it would accomplish the same goal. Schuyler said it would not be big enough. Olivier said it would be if the community chose to stop growing. John Martin, representing the Rivanna River Basin Commission, said there was no guarantee the community could do that for 50 years. Schuyler pointed out the City has changed its zoning to allow for a denser population. Olivier said the County and City have financially supported an optimal population study being advanced by Advocates for a Sustainable Albemarle Population (ASAP). Martin asked Olivier if a smaller water supply should be built so the area can’t support further growth. Olivier said that was not she wanted to do.
Fletcher said he would have appreciated a better understanding of how the reservoirs are connected.
Martin said that one important feature of the new water supply plan is that the South Fork pipeline would allow water to be transferred in both directions in case more water was quickly needed.
Dede Smith asked how the full Ragged Mountain Dam would be initially filled. Schuyler said it would be filled via the pipeline from Sugar Hollow because the new South Fork pipeline would not be built for a number of years. Smith asked if all two and a half billion gallons could be filled via Sugar Hollow. Schuyler said the process would be much slower, but it could be done. Liz Palmer of the Albemarle County Service Authority said that the existing pipeline is 81-years old and will need to be replaced at some point.
Dede Smith said if there was extra capacity at South Fork, then there would be no need to build a new pipeline. Palmer said that either way, the community was going to have to build one of three lines to transfer water from a supply source to a storage basin. That could come through rebuilding the Sugar Hollow pipeline, building the pipeline from South Fork to Ragged Mountain, or by building a pipeline to the James River.
That prompted Olivier to say that the community never talks about water conservation. Palmer and Martin vehemently disagreed.
Dede Smith took issue with the amount of water storage capacity that would be restored if the community did a one-time dredge and then continued to dredge. She said that the task force should report that at least 1 billion gallons of capacity would be restored. Thomas’ presentation claimed 400,000.
Tom Jones said at one point that the conclusions of the adopted water supply plan were put “off-limits” and that it was not acceptable to present them if the task force had not reviewed them. Fletcher suggested just including the references as a bibliography and said the work of the task force was to make recommendations, not confirm every figure that has been published on the reservoir.
Karen Joyner of the Ivy Creek Foundation said the task force should have discussed the water supply plan so these issues could have been cleared up. She said there has been a lot of misleading information about how the water supply plan would work and why it is needed.
“We should have a session on this to make sure we all understood it,” Joyner said. Fletcher said that the task force’s recommendation should include a disclaimer that says that the task force did not discuss the water supply.
Palmer said having the information about the reservoir would be useful in case the task force decides to recommend dredging. Schuyler said the task force was not charged with whether the South Fork should be dredged for water capacity because that decision has been made.
“But that doesn’t mean that expanding capacity for other reasons is not a by-product [if] we do dredging for other reasons,” Schuyler said. “We could certainly say back to them that [extra capacity] would be the effect of maintenance on the [reservoir].” He said that any extra capacity would be in addition to the water supply plan’s goals, but doubted that the height of the Ragged Mountain Dam would be affected by more than a foot with this added supply taken into account.
Jones said that he was skeptical of Schuyler’s claim that the pipeline would only be used for an average of 20 days a year because he thought that Ragged Mountain would be the primary water source.
Jones said he could not imagine the South Fork being used as a reservoir if it only has a usable storage capacity of 250 million gallons. Schuyler said that the supply for Ragged Mountain would come through the natural flow of the river and all the new plan did was shift storage away from the supply.
Martin said that the task force’s recommendations should start from the assumption that dredging is not required to meet the water supply demands of 2055. “Our job is to say given that fact… do we want to dredge anyway, and why?”
After the task force finished the exercise, Tom Jones handed out a list of his recommendations. Though he said his proposal was a straw-man, he suggested the task force should recommend that the four boards request a dredging feasibility study that would provide a bathymetric study, a side scan, geotechnical samples, an evaluation of disposal sites as well as a cost estimate. His proposed objectives would include dredging for water supply capacity, to add redundant capacity to the system, and to preserve opportunities for rowing and fishing.
“[My proposal] does not take a position and I don’t think it’s our task force’s charge to take a position to say when the estimates come in for dredging that we ought to dredge at any price,” Jones said. “There clearly are uncertainties associated with the ultimate cost of the Ragged Mountain plan and I don’t make a statement that’s due to any incompetence or malfeasance or errors on anybody’s part. I think that just comes with the engineering
Time expired before the task force could take up Jones’ proposal. The group has two more meetings scheduled this year. It is expected that a full report will be made to the chairs of the four boards early next year.
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