If conditions warrant, the Rivanna Water and Sewer Authority executive director could declare a drought watch or drought warning without a special meeting of the authority’s board.
The Rivanna Water and Sewer Authority Board on Tuesday authorized the authority’s executive director to, if warranted by reservoir and stream conditions for the local water supply, declare a drought watch or warning and with concurrence from the chair before the board’s next meeting on Sept. 28.
Bill Mawyer, executive director of the RWSA, said the authority wants to be prepared in case the hot and dry weather continues.
“We’re not recommending that [restrictions] are needed now,” he said.
According to the National Weather Service, the area has received about five inches less rainfall than normal so far this year. NWS is forecasting a slight chance of showers and thunderstorms for the rest of the week, with increasing possibility at the end of the week and into the weekend.
A drought watch enacts voluntary water use restrictions and a drought warning allows local governments to enact mandatory water use restrictions.
Charlottesville requires action by the City Council to activate mandatory restrictions. The Albemarle County Service Authority has policies in place to initiate mandatory water use restrictions as soon as the RWSA declares a drought warning, provided that the Albemarle Board of Supervisors also has declared that conditions exist.
Mawyer said the authority ran a computer model that looks at historical weather precipitation in the area over the last 80 to 100 years.
“The model indicated that it did not anticipate we would be in drought conditions at the reservoir — that is that the reservoir would not be down low enough to justify water conservation measures,” he said.
A drought warning and mandatory restrictions have not been declared since 2017, when, in addition to dry weather, the authority had leaking stream release gates and was releasing more than the required amount of water into the Rivanna River.
In an interview ahead of the meeting, Mawyer said that the gates have been repaired.
“We’re trying to be proactive and monitor because in two or three weeks of hot weather and no rain, all the stream flows and the reservoir levels could be significantly different,” he said.
Last week, the U.S. Drought Monitor included parts of Albemarle as being in “Moderate Drought,” while the rest of the county was “Abnormally Dry.” A new map will be released Thursday morning based on updated data.
An Aug. 23 map from the Virginia Department of Environmental Quality shows that precipitation, groundwater levels, streamflow and reservoir levels are all currently normal for the drought evaluation region that covers Charlottesville and Albemarle.
The South Fork Rivanna Reservoir, which currently provides most of the water to the city and Albemarle’s urban ring around it, is full and overflowing. Mawyer said if water stopped flowing over the dam, there would be approximately 60 to 90 days of water available remaining in the reservoir.
The Ragged Mountain Reservoir, which also serves the urban area, has a greater amount of storage than South Fork Rivanna Reservoir, but its treatment plant can currently only treat about 3 million to 4 million gallons per day. The South Rivanna Treatment Plant can treat 10 million gallons per day.
“That’s why we monitor South Rivanna because it’s smaller than Ragged Mountain Reservoir, but we’re pulling more water out of it to treat it at the South Rivanna Treatment Plant,” Mawyer said.
The authority is working to expand treatment capacity at Ragged Mountain Reservoir’s treatment plant to 10 million gallons per day. It’s also working to build a raw water pipeline between the Ragged Mountain and South Fork Rivanna reservoirs.
“That’s why it’s important for us to build this pipeline from the South Rivanna Reservoir over to the Ragged Mountain Reservoir, so that we can get water out of our largest reservoir at Ragged Mountain and treat it at the South Rivanna treatment plant, which is our largest treatment plant, when needed,” Mawyer said.
Beaver Creek Reservoir, which serves the Crozet area, is about 87% full, but Mawyer said it still has about seven months of capacity based on the area’s use of about 1 million gallons per day.
“We feel like the Beaver Creek Reservoir and the Crozet community on the public water supply side is in very good shape,” he said.