Hydroelectric dam repairs to cost $500K

NASHUA – The city’s Jackson Mills hydroelectric dam is getting a turbine repaired to make sure it can keep generating until more thorough work can be done.

According to a letter Mayor Jim Donchess sent to Aldermen, the dam’s turbine failed this summer when it detached and landed near the end of turbine shaft in the river. Repairs currently are underway, and the facility is expected to be back online, generating electricity and revenue for the city next month.

The repairs are costing the city $500,000, though Donchess is seeking to use unanticipated city revenue to cover the costs. This repair is not a permanent fix for the dam, however.

“Ultimately, the turbine will still need to be replaced,” Donchess wrote.

Donchess plans to start budgeting for the design work in the fiscal 2019 budget, and the fabrication of the new turbine in the fiscal 2020 budget.

“The goal is to be prepared to replace the turbine within a short timeframe, when a major break occurs so that the project can generate electricity and revenue for the city reliably for an additional 30 to 40 years.”

Nashua took control of the the dam in 2015 after a long-term lease on the property expired. Nashua has since contracted with the company, Essex Power Services, to operate both the Jackson Mills and the Mine Falls hydroelectric dams. Donchess said Jackson Mills generated more than $260,000 in revenue for the city in 2016, slightly below estimates, due to drought conditions. The Mine Falls project, however, has been on the uptick by about 13 percent above estimates due to good river flow this year.