Drought warning continues amid growing concerns about Sugar Hollow Reservoir
On November 26, 2007, the
Rivanna Water and Sewer Authority
(RWSA) held their monthly meeting. Executive Director Tom Frederick provided a “sobering” update on the area’s continuing drought warning. Despite recent rainfalls, the Sugar Hollow Reservoir remains 12 feet below full and there is growing concern that the reservoir may not refill before next Spring.
A pipeline built in 1925 runs from the Sugar Hollow Reservoir in the mountains above White Hall to the Ragged Mountain Reservoir near Charlottesville. According to Frederick, during November, the RWSA shut down the Sugar Hollow water supply intake depriving Ragged Mountain of its main source of new water. Ragged Mountain is currently 1.6 feet below full and its water storage is now being withdrawn by the Observatory Hill Water Treatment Plant. “In a situation like we are in right now we will routinely switch [sources], because what we are trying to do is put both reservoirs in relative balance to each other, so when we do get rain we get the maximum opportunity for refill,” said Frederick.
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Since Sugar Hollow has not been utilized for urban water supply needs, RWSA has been able to make a closer examination of the actual water flows coming from Shenandoah National Park into the reservoir. In the past, flow predictions have been made based upon the Mechums River flow gage. That has been used as a rough predictor of what was happening in the Sugar Hollow watershed that feeds into the Moormans River. Based upon observations this month, RWSA’s data shows that Sugar Hollow has only 22% of the flow that would have otherwise been predicted. Frederick said, “That was a surprise to some of us, that it was that different.”
After ruling out potential causes for under counting the stream flows, RWSA has concluded the 4 inch rainfall in late October had only a “marginal positive effect” on the streams feeding Sugar Hollow. Frederick said Sugar Hollow is the most critical facility for RWSA right now and the Authority’s goal is to have all its reservoirs full before next Summer. As a result of this assessment, Frederick informed the Board that, “There is still a lot of concern at the staff of the Rivanna Water and Sewer Authority that, without more rain than we’ve been getting so far this fall and winter, there’s a chance we may not fill Sugar Hollow by spring.”
After this update, the Board left the Drought Warning status in place.
In other business, the Board received an update from Ron Taylor, a consultant with the engineering firm of Hazen and Sawyer. Taylor provided an update on the design work for upgrades to the Moores Creek Wastewater Treatment plant which are expected to cost about $35.9 million. Upgrades will ensure that RWSA can comply with new nutrient removal regulations related to the protection of the Chesapeake Bay watershed. The Board took action to refine the final design and to allocate another almost $1.7 million to Hazen and Sawyer to complete the final design and execute the bid process.
Taylor also shared with the RWSA some concerns about current trends in the inflation for construction costs and the fact that a perfect storm was developing with respect to these nutrient removal compliance projects around Virginia. Approximately ninety treatment plants will need to be upgraded in Virginia By January 1, 2011 and there is insufficient labor and construction resources in the region to complete that work. Thirteen of the ninety localities have gone to bid thus far and three of those localities (Henrico, Fishersville, and Culpeper) saw bid prices 29-44% above what their engineering firms had originally estimated. Over the next two months Hazen and Sawyer will finalize work on the design and the project’s cost estimates.