THOMPSON, CONN. -- People who do not know him well have referred to Bob King as "driven" or "ambitious." His best friends tend to favor "insane" as a more accurate description of the man who rebuilt the Mechanicsville dam.

In 1985, fresh out of Cornell University with a degree in mechanical engineering and definite ideas about the way the world should work, King came to a sleepy valley in northeastern Connecticut seeking a way to generate good, clean power.

"I was poking around, looking for a small hydroelectric power site to rebuild," he recalled. "I knew what I wanted to do. It was just a matter of finding the right site. It's something I've wanted to do since I was 10."

King, 29, did find it, and what has transpired in the five years since then is a tale of work, politicking and good old-fashioned American profit motive. Most of all, it is a story of work -- blood and guts, heave-ho, nose-to-the-grindstone labor.

Mechanicsville dam on French River had been the pride of the Connecticut Light and Power Co., a "flagship" facility before it was closed in the late 1930s as part of a consolidation and fell into ruin. Then the whole complex was washed out, along with most of the rest of Quinebaug Valley, in the great flood of 1955.

To renovate the site, King had to remove more than 50 years of slime, rusted metal and garbage. Tons of mud and catfish had to be mucked out of dilapidated, crumbling canals first built with the dam 150 years ago. Family and friends supplied the muscle, holding weekend "work parties" on which old college buddies and friends of friends arrived to help install a turbine or build a coffer dam.

Local residents have supported the project from the beginning, visiting the site to work, help or sometimes just kibitz.

King and his partner, Mit Wanzer, 26, joke about it now. "It was kind of like, 'Hey, man, great to see ya! Now grab this shovel and get out in the pond,' " King recounted.

As he talks about the dam, something seems to flicker behind his eyes, a kind of subdued frenzy. His father, George, likes to say that Bob has "got the bug."

It is easy to picture King standing neck deep in poison ivy back in 1985, looking at the devastated dam and saying, "Yeah, I can get this thing going again."

And he did. It is called Saywatt Hydro Associates, a self-explanatory play on words but kind of a dumb one, King and Wanzer are first to admit. Behind that title on business cards is their logo, a question mark with a lightning bolt slashing through it.

King, who acts as a consultant on other hydroelectric projects nationwide, bought the property, dam and powerhouse for $40,000, which he had saved while working as an engineer during the summer. His parents also lent a chunk. Bought brand new, the type of turbines -- also known as water wheels -- needed to generate power would cost about $200,000 each. The first cost him $50.

"I got it out of a junkyard," King said. "It was being scrapped out. It's amazing what people will throw away."

Equally amazing is the story of how that turbine and one other now work together to produce more than 200 kilowatts of marketable electricity, bringing in a monthly check from the power company of between $50 and $3,000, depending on the amount of rainfall and the amount of electricity generated. When rain pushes enough water toward the dam, Saywatt can generate power to as many as 250 houses.

The property's last owner was Essex Hydro Associates of Boston, which bought the land after passage of the 1979 Public Utility Regulatory Powers Act (PURPA) made redevelopment of such ancient, abandoned dams economically viable. The act requires utilities to buy power produced by small hydroelectric sites, windmills and solar producers. With PURPA, the walls that separated the Bob Kings from their dreams came crumbling down.

After King left Cornell, he started working for Hydro Associates. They finally reached agreement in 1987, and King had his dam.

On a recent Saturday night, King and many of the original shovelers and muckers gathered here around a freshly painted railing in the dam's powerhouse, the muscle and brain of the operation. It contains both huge turbines, the gearbox and the control panels.

Everyone along the railing was peering down at the second turbine. Painted on the middle of the wheel sitting atop it was the Chinese symbol for the yin and yang, the active and passive forces of the universe. Nearby was a bulletin board full of snapshots: a group of soaked men and women hauling a rusted pipe out of the pond, a small front-end loader perched precariously on the end of a temporary structure used in building the dam.

After a speech by King, short and sweet and expressing gratitude for everyone's help, the turbines suddenly began whirring. A bottle of champagne was smashed against the "water wheel," and a celebration began. With a roaring camp fire outside, guitars resounding and laughter echoing off the powerhouse's high, vaulted ceilings, about 100 friends hailed Saywatt Hydro Associates as a viable part of the local power grid.

The major unresolved problem involves the local Providence and Worcester Railroad, whose twice-daily freight trains cross the dam's lone access road and whose spokesman said the crossing "is badly in need of rehabilitation." P&W workers have placed concrete blocks along the tracks to block vehicle access, and officials want Saywatt to buy a $2 million liability insurance policy. King said he does not have the money, and, for now, dam visitors simply park their cars and walk across the tracks.

At the celebration, a good fire crackled, and the mood was decidely upbeat.

"It gets down to diversity," said Mit's brother, Charlie, 29, between bites of barbecued chicken.

"It diversifies the existing power structure, it diversifies the society. Just about everybody here's had a liberal arts education, we study local history and ecology and culture, we imagine ourselves having a role in the brightening of our future."