Output From Vermont’s Hydro Plants Drops Because of Dry Conditions

Rivers have been running low due to a dearth of rainfall, meaning less water rushing through the turbines of hydro plants

This summer's dry conditions have resulted in a drop in output from the hydroelectric power generation plants belonging to Vermont's largest consumer utility.

Rivers have been running low due to a dearth of rainfall, meaning less water rushing through the turbines of hydro plants. 

Green Mountain Power said during June, July, and August of 2015, its hydro plants produced enough electricity on average to power 96,000 Vermont homes. However, to-date in the dry summer of 2016, the output has only been enough for 55,000 households, the utility said.

"This would be kind of the low-of-the-lows that we've seen for a number of years," said Jason Lisai, GMP's generation manager. "We'd definitely like to be generating more power than we have been this year." 

Lisai said the drop in water levels did allow for maintenance work on the utility's riverside infrastructure. 

Green Mountain Power said because electricity prices from other sources have been low, consumers shouldn't see any cost jumps from this summer's drop-off in hydro generation. 

A utility spokeswoman noted that while this summer's hydro output has been disappointing, GMP looks at the renewable power source as a long-term investment. The utility said output from hydro actually exceeded expectations in the last decade.

GMP called hydroelectric generation an important part of its portfolio and said the resource has served Vermonters well as a baseline power source for many years, and predicted it will continue to in the future. 

This week, a fast blast of two to three inches of rain washed out some roads in the central Vermont communities of Duxbury, Moretown, and Fayston. Much of that water flowed to the Winooski River and ended up causing a more than five-foot rise in some spots along the river, according to the National Weather Service. 

That rise in water levels caused output from GMP's hydro turbines on the Winooski to jump Wednesday and Thursday, Lisai noted.

The Winooski River is one of the few in the state that's running at close to normal levels, following this week's rainfall. It's at about 90 percent of its normal height, the National Weather Service said.

Rivers in the southern part of Vermont are generally running 20 to 40 percent of their normal heights, the NWS said. Closer to Canada, northern waterways are about 40 to 50 percent of their normal heights, the NWS added.  

Dave Leonard of Winooski walks by the Winooski River daily, and noticed its rebound this week from earlier low levels. 

"Sometimes it hurts to see it that way," Leonard said of what were visibly-low water levels earlier this month. "But you can't control Mother Nature."

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