For nearly two centuries there has been a dam across the Des Plaines River in the area of what is present-day Riverside. Two weeks from now, the dam will simply be a memory.

Promptly at 7:15 a.m. Wednesday morning an excavator from Illinois Constructors Corporation scuttled across the shallow bed of the river, under the Barrypoint Bridge and onto a rock platform in front of the Hofmann Dam – the most recent structure, built in 1950.

Click here to see photos from the demolition.

Outfitted with a sledgehammer attachment, the excavator swung its arm into position and began chipping away. Rat-tat-tat-tat.

There was no stopping the dam removal now. Over the next hour, the excavator methodically pounded away at the center face of the dam, gradually opening up a notch through which water began to pour.

“I’m sad to see it go, but if it improves Swan Pond or the river flow and stops flooding up river, it’ll be worth the eight or nine years it’s taken,” said Tim Forney, a Riverside resident for the past 41 years.

While the removal of the dam is expected to have little, if any, impact on flooding, the main purpose of the project is to improve the ecosystem above the dam and eliminate a proven safety hazard.

Forney said he has canoed in the river above and below the dam and is looking forward to being able to paddle down the river unimpeded through Riverside.

“You get a nice view through here,” he said.

Lyons resident Bruce Von Ohlen, who lives in the Riverwalk Condominiums on the south bank of the river near the dam thinks the project is a bad idea.

“I think it’s a waste of taxpayer dollars,” Von Ohlen said. “There’s no reason to do it. It’s really quite a shame.”

Another Riverside resident, a woman who declined to give her name, said she’s a little nervous about what the removal of the dam will mean in the long run.

“I hate to see it go,” she said. “If it’s a positive, that would be great, but I’m not convinced. If there are negative effects, hopefully they can rectify them.”

She wasn’t the only person in Riverside afraid of the negative effects of the dam removal. Since April, residents who live along Maplewood Road have pleaded with village officials to pull their support for the project, claiming lower water levels might have a negative impact on their properties.

But on June 11, village trustees refused to reconsider the measure, setting the stage for Wednesday’s operation.

When work is complete on July 7 (weather permitting), the center 150 feet of the concrete dam will be gone, removed all the way to bedrock and the water will seek the natural channel of the Des Plaines River, one that hasn’t been seen much since 1827, when the Laughton brothers built the first dam for a sawmill atop a natural waterfall.

That dam was rebuilt several times, first in 1866 and then in 1908 by George Hofmann, who constructed a horseshoe-shaped dam to create a pool of water to be used alternately for recreational purposes and to supply electricity to his adjacent recreational park in Lyons.

What Hofmann’s dam actually succeeded in doing was to create an open sewer behind it. When Hofmann ignored complaints about the pollution, the Sanitary District of Chicago in 1928 built a bypass on the Riverside side of the river to wash the pollution downstream.

In 1950, after deterioration of the top of the horseshoe dam had dropped water levels to near bone-dry, the state of Illinois replaced it with the present dam.

Storm water runoff due to increased urbanization and the influx of water from 11 treatment plants upstream of Riverside have significantly increased flows in the Des Plaines since 1950, say officials, making it far less likely to experience the kind of low water levels seen at that time.

Photos from day 2