Puget Sound Energy will be able to move forward with major renovation at its 111-year-old Snoqualmie Falls hydroelectric power plant.

Federal regulators issued PSE a key amendment to the utility’s operating license for project on Monday, June 1, company officials said in a news release.

Construction work will ramp up in September, and is expected to last, in stages, through 2014.

Under the 40-year operating license PSE received five years ago from the Federal Energy Regulatory Commission, and the license amendment the commission issued Monday, the utility will be making substantial upgrades to the historic plant’s power-generating infrastructure. PSE also will be making major enhancements to the recreational facilities it provides to Snoqualmie Falls’ 2 million annual visitors.

“Snoqualmie Falls is a scenic and cultural treasure that’s also been giving our region clean, renewable, carbon-free energy for more than a century,” said Paul Wiegand, vice president of Power Generation for PSE.

“With our amended license, we’re in a position to carry forward the project’s legacy well into the 21st century,” he added.