Next to this artifact, the company plans to dig 135 feet down into solid rock. In this hole, the company proposes to build a second powerhouse. The building would be smaller than the old one but would hold two new hydroelectric generators twice as large as the 1910-era machines. The new turbines could pump out 125 megawatts of power, more than doubling the dam's current capacity.
"The new building will be built right here," Porse said, pointing to a blue line that has been spray painted in a box shape on blacktop near the dam's entrance. "For people in the hydroelectric industry, this is a once-in-a-lifetime project."
Downstream from the dam, much of the Susquehanna River is a barren-looking washboard of boulders, wetlands and scrubby trees. Beside this riverbed, a narrow, fast-moving stream pours out of the dam's outfalls into a narrow, stony valley. The current flows too fast for rare American shad to migrate along this route upstream to spawning grounds.
The Holtwood project would attempt to address this problem by dynamiting and excavating in a roughly mile-long section of the Susquehanna River to make the channel wider, said Porse.
This would slow the current and help the passage of migrating fish. If they can make it through a slower current, the shad could swim into a mechanical fish lift built 10 years ago on the dam. The elevator hasn't been a success because fish can't get to it, Porse said.
An environmental activist who has been studying the project, Michael Helfrich, the Lower Susquehanna river keeper, said adding more turbines could chop up more fish that pass through the dam. But he said adding more hydroelectric generation is a good idea.
He noted that this section of the Susquehanna is already one of the most generating-intensive areas of the world. Two nuclear plants (Three Mile Island and Peach Bottom), four hydroelectric dams (including Maryland's Conowingo), a coal-fired plant, a natural gas plant and a municipal incinerator all line a 50-mile stretch of the river.
"I would rather see the hydros than any of the other power plants that are up and down this river," Helfrich said. "Hydroelectric power isn't impact-free, but it creates no greenhouse gases - and I think it's better than coal, natural gas or nuclear as a way to get electricity."
tom.pelton@baltsun.com
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