“The discussion in recent months has been that this is coming – and at some point we will have to curtail,” said Augusta Utilities Director Tom Wiedmeier.
The canal is a drinking-water source for about 160,000 households in the city, and its flow provides hydromechanical power that pumps raw water to the city’s filter plant off Highland Avenue, saving $1.5 million a year in energy costs.
The waterway also turns turbines at Enterprise, King and Sibley mills that generate electricity – and money – for the Augusta Canal Authority and its recreation and historic preservation projects.
City officials hope the canal authority can be persuaded to reduce power generation if a request is made to do so, Wiedmeier said.
The area of concern during low water is the Augusta shoals, a segment of the river bypassed when water is diverted into the canal, even if some of that water eventually finds its way back into the river three to seven miles downstream.
The exact flow required to be left in that “bypass” area remains in limbo until a long-delayed license for the canal is finalized by the Federal Energy Regulatory Commission. Until then, city officials and environmental regulators adhere to a general target of at least 1,000 cubic feet per second, Wiedmeier said.
Dayton Sherrouse, the executive director of the canal authority, said current releases from Thurmond Dam – averaging about 3,800 cubic feet per second – provide a barely adequate flow.
“It can take care of Utilities and all three of mills,” he said. “But if it drops down lower than 3,800, then we are going to have reductions.”
Four years ago, before Sibley Mill was acquired by the canal authority, city officials required the previous owners to reduce power generation about 30 percent when water supplies dwindled.
Today, revenue from the three mills combined provides about 58 percent of the canal authority’s operating budget. The percentage could become even larger this fall, when legislation that provides federal money for the Augusta Canal Heritage Area will expire.
Sherrouse said he hopes any reduction in turbine use can be implemented across the board, rather than to one facility, as it has been in the past.
“The reality is, there is a finite amount of water, and in a drought that amount is reduced,” he said. “It’s a situation where everyone has to adjust and do things a little differently.”